The biannual Journal of the Malaysian Journal of Catalysis (Malay. J. Catal.) is open access and peer-reviewed research journal published by the School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia supported by the Malaysian Catalysis Society (MCS). This journal is a free-processing fee and will be published on January-June and July-December. The aims and scope of the journal encompass research articles, original research reports, reviews, short communications, and scientific commentaries from fundamental principles to practical applications in the broad field of homogeneous, heterogeneous, and biocatalysis. All manuscript submissions must be made through the journal's online manuscript system at "Submission". Indexed by: MyJurnal Topics of the journal (but are not limited to): 1. Catalytic Mechanisms 1-1. Spectroscopic and Visualizing Characterizations 1-2. Surface Chemistry, Reaction Kinetics and Mechanisms 1-3. Molecular Simulation and Theoretical Modeling 1-4. New Concepts for Catalysis 2. Catalytic Materials 2-1. Nanostructured Catalytic Materials 2-2. Micro- and Meso-Porous Catalytic Materials 2-3. Hybrid materials for catalysis 2-4. Novel Design and Synthetic Approaches 3. Catalysis for Energy 3-1. Efficient Utilization of Fossil Sources 3-2. Clean Energy Conversion: Electrocatalysis 3-3. Biomass Conversion 3-4. Photocatalysis for Hydrogen Production 4. Environmental Catalysis 4-1. Automotive Exhaust Cleanup 4-2. Water Pollution Control 4-3. Air Pollution Control 4-4. Updating and Utilization of Wastes 5. Catalysis for Chemical Synthesis 5-1. Green Synthesis 5-2. Petrochemicals 5-3. Fine Chemicals and Pharmaceuticals 5-4. Selective Oxidation & Hydrogenation 6. Cross-Disciplinary 6-1. Integration of Heterogeneous and Homogeneous 6-2. Organic and Biomimetic Catalysis 6-3. Industrial Catalysis 6-4. Other Surface Active Site Phenomena 6-5. Adsorption-Desorption Phenomena 6-6. Active sites Studies 6-7. Others Click for template of MJCAT Manuscript Publication Ethic & Malpractise Statement Guide for Authors Guide for Editors Guide for Reviewers Recent Articles : >>Characterization of Ni catalyst supported on α-Al2O3 and SiO2 for Syngas Production via Dry Reforming of Glycerol >>Characterization of iron-doped mesoporous silica nanoparticles for CO2 methanation eISSN : 0128-2581 Abbreviation: Malay. J. Catal. Imprint: School of Chemical and Engineering, Faculty of Engineering. UTM Johor Bahru
School of Chemical and Energy Engineering, Universiti Teknologi Malaysia
The Malaysian Journal of Catalysis publishes open access articles under the terms of the Creative Commons Attribution (CC BY) License which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The Department of Chemistry, Faculty of Science, UTM retains the Copyright on any research article published by Malaysian Journal of Catalysis. Authors grant Malaysian Journal of Catalysis a license to publish the article and identify itself as the original publisher.
Green Mg-Ca-Al Mixed Oxide Catalyst for Synthesis of Glycerol Carbonate
This study aims to investigate the transesterification of glycerol with dimethyl carbonate (DMC) to produce glycerol carbonate (GLC) using a heterogeneous Mg–Ca–Al mixed-oxide catalyst. Catalysts with different molar ratios of Mg, Ca, and Al (Mg₃.₅ₓCa₀.₅ᵧAlₓO₃) were synthesized and calcined at 500 °C for 5 hours to determine the optimal composition for achieving a high GLC yield. Among the synthesized catalysts, Mg₁.₀₅Ca₀.₇₅Al₀.₃O₃ was identified as the most effective. The results revealed that the Mg₁.₀₅Ca₀.₇₅Al₀.₃O₃ catalyst exhibited higher catalytic activity when calcined at an elevated temperature of 800 °C. Characterization techniques, including SEM, HRTEM, BET, XRD, and FTIR, were employed to analyze the structure, morphology, composition, porosity, and surface functionality of the catalysts. All transesterification reactions were conducted in a batch process under varying conditions: catalyst loading (2–5 wt%), DMC-to-glycerol molar ratio (1:1–4:1), reaction temperature (65–80 °C), and reaction time (0.5–2.0 hours). The optimum reaction conditions were identified as a catalyst loading of 3 wt%, reaction temperature of 70 °C, DMC-to-glycerol molar ratio of 3:1, and reaction time of 1.5 hours. Under these conditions, a GLC yield of 75% was achieved, with a glycerol conversion of 76%. The stability of the Mg₁.₀₅Ca₀.₇₅Al₀.₃O₃ catalyst was evaluated over three consecutive cycles. The results indicated that aluminium plays a crucial role in enhancing catalyst stability by providing a high surface area and acting as a support. Furthermore, the presence of aluminium reduces the basicity of the catalyst, thereby minimizing the formation of glycidol.
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Tin-Doped Titanium Dioxide Photocatalysts Prepared via Hydrothermal Method: Effect of Calcination Temperature on Dye Degradation Efficiency
The widespread discharge of persistent and toxic synthetic dyes from the textile industry into aquatic ecosystems has critically compromised global access to clean water. Conventional treatment techniques are often inefficient in removing these pollutants. Among advanced oxidation processes (AOPs), photocatalysis has emerged as a promising solution for degrading dye-contaminated wastewater. While titanium dioxide (TiO2) is a prominent photocatalyst for wastewater treatment, its practical application is limited by a wide band gap (3.2 eV) and rapid electron-hole recombination. This study reports the preparation of tin-doped titanium dioxide (Sn-doped TiO2) as a photocatalyst via a hydrothermal method, with a systematic focus on optimizing calcination temperature. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), which confirmed a pure anatase phase with the crystallite size increased at higher calcination temperature. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) analysis verified the presence of tin within particle clusters, while diffuse reflectance ultraviolet-visible (DR UV-Vis) and Fourier transform infrared (FTIR) spectroscopies confirmed extended visible-light absorption and successful lattice incorporation. Furthermore, photoluminescence (PL) results indicated that Sn-TiO2 (400 °C) exhibited a more ordered crystal structure, reducing non-radiative recombination. Photocatalytic evaluation via methylene blue (MB) degradation under visible light revealed that Sn-doped TiO2 calcined at 400 °C achieved the highest efficiency of 65.2% after 7 hours. This enhanced performance was attributed to the synergistic effects of a narrowed band gap (3.14 eV), high crystallinity, and optimized crystallite size. These findings demonstrate that controlling calcination temperature is crucial for developing efficient, visible-light-active photocatalysts for sustainable industrial wastewater remediation.
Commercial Silica-Supported Niobium-Doped Titanium Dioxide for The Photocatalytic Degradation of Methylene Blue
Water contamination caused by mutagenic dyes has intensified research into the Advanced Oxidation Process (AOPs), a promising method to mineralize dye pollutants. The widely used TiO2 catalyst can overcome this current issue; however, it still experiences agglomeration despite its high catalytic activity, thereby reducing surface area and increasing charge recombination. To overcome this limitation, this study modified a niobium-doped titania photocatalyst by introducing fumed silica, a high-surface-area support, to improve titania dispersion. A series of SiO2/Nb-TiO2 photocatalysts with different silica-to-titania molar ratios was prepared via the sol-gel method with sonicator assistance and characterized by X-ray diffraction (XRD), Fourier transform infrared-attenuated total reflectance (FTIR-ATR), diffuse reflectance UV-Visible spectroscopy (DRUV-Vis), and nitrogen adsorption-desorption analysis. XRD analysis confirmed anatase TiO2 phase presence, successful substitution of niobium into the titania lattice, and the appearance of a broad amorphous hump in the silica-supported catalyst (20 SiO2/Nb-TiO2). DRUV-Vis Spectroscopy revealed that the absorption edge of the silica-supported samples shifted to deeper ultraviolet light due to quantum size effects. Among all samples, the optimum silica molar ratio was 10 SiO2/Nb-TiO2 due to a lower bandgap, the highest surface area (180.81 m2/g), and the highest degradation activity (76.60%) at a 5 ppm methylene blue. These findings demonstrate the synergistic interaction effects of niobium doping and an optimum silica support in enhancing photocatalyst performance.
Green Synthesis of ZnO Nanoparticles for kinetics and thermodynamics studies of the photocatalytic degradation of eriochrome black t and methylene blue dyes
This work presents a biosynthesis of zinc oxide nanoparticle (ZnO NPs) from the Vigna unguiculata L extract via co-precipitation method. The prepared photocatlyst was characterized using thermogravimetric differential thermal analysis (TG-DTA), Bruneur-Emmett-Teller (BET), X-ray diffraction (XRD), ultraviolet-visible (UV/Vis), Fourier transform infra-red (FT-IR) and energy dispersive x-ray fluorescence (EDXRF) analyses.TG-DTA results revealed that the calcination temperature was found to be 600 ℃. BET specific surface area was 190.04 m2g-1. The average crystallite size and band gap values were 50.10 nm and 3.25 eV, respectively. FT-IR analysis demonstrated that the vibrational absorption band of 637 cm-1 corresponds to the Zn-O bond. EDXRF result confirmed the presence of Zn and O atoms in the ZnO. The optimal degradation efficiencies of 98.05 & 97.51, 96.58 & 95.65, 96.45 & 94.98 and 96.75 & 93.25 % were achieved at 10.00 mg/L eriochrome black t (EBT)/ methylene blue (MB) initial concentrations, 1.50 g/L ZnO dosage, initial pH of 9.00 and 50.00 ℃ initial temperature in 120.00 min irradiation time respectively. The photocatalytic removal of EBT and MB over ZnO NPs was followed pseudo-first order kinetics with apparent rate constant of 5.33 x 10-2 and 4.91 x 10-2 s-1, respectively. Activation energy (Ea), enthalpy change (ΔH), entropy change (ΔS) and Gibbs free energy change (ΔG) were + 8.94 & + 14.65 k J mol-1, + 6.27 & + 12.02 k J mol-1, - 82.86 & - 61.56 J mol-1K-1 and + 31.37 & + 30.67 k J mol-1 for the photocatalytic removal of EBT and MB, respectively
Effect of Ceria Doped on Fibrous Silica Titania Catalyst for Enhanced Photodegradation of Ciprofloxacin in visible light
Advanced oxidation processes (AOPs) is one of the most promising methods to degrade such organic pollutants from water. Titania (TiO2) is the most attractive semiconductor photocatalyst due to non-toxicity compound and low cost. Notwithstanding, its application is limited owing to the wide band gap, high recombination rate of the charge carriers, low surface area and low absorption of light. This study was focused on the synthesis of different ceria (Ce) loading on fibrous silica titania (FST) by using hydrothermal and impregnation method. The physical and chemical properties of FST-Ce was characterized by X-ray diffraction (XRD), ultraviolet visible spectrophotometer diffuse reflectance spectroscopy (UV-Vis/DRS), field emission scanning electron microscope (FESEM) and fourier transform infrared (FTIR); and the performance of photocatalytic activity was evaluated on the photodegradation of ciprofloxacin (CIP) under different type of catalysts, pH, catalyst dosage and CIP initial concentration. The result revealed that FST-3Ce showed the best performance due to low band gap, high crystallinity and strongest interaction between Si-O-Si, Si-OH, and Si-O-M bonds. A kinetic study using Langmuir-Hinshelwood model illustrated that the photodegradation followed the pseudo-first-order and adsorption was the rate-limiting step.
Mesostructured TiO₂–g-C₃N₄ Hybrid Nanocomposites: A Potential Solar-Driven Solution for Textile Dye Pollution
The development of efficient solar-driven photocatalysts is crucial for sustainable treatment of dye-contaminated textile wastewater. In this study, a mesostructured titania/graphitic carbon nitride hybrid nanocomposite (MTNCN) was successfully synthesized via a sol–gel method and evaluated for the photodegradation of methylene blue (MB) under ultraviolet, visible, and solar irradiation. The structural and physicochemical properties of the synthesized materials were systematically characterized using X-ray diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray analysis (FESEM–EDX), N₂ adsorption–desorption (BET) analysis, and UV–Vis diffuse reflectance spectroscopy (UV-Vis DRS). The results confirmed the successful incorporation of CN into MTN, leading to enhanced textural and optical properties attributed to the formation of an effective heterojunction. Among all samples, MTNCN exhibited superior photocatalytic activity, achieving 78.2% MB degradation within 30 min and 97.3% after 180 min under solar irradiation, outperforming both pristine MTN and CN, even under UV light. The enhanced performance under solar irradiation highlights the strong potential of MTNCN as an efficient and sustainable photocatalyst for textile dye wastewater remediation.
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The Epoxidation of Cooking Oil Using Heterogeneous Catalyst Via Peracids Mechanism
The increasing demand for sustainable and environmentally friendly materials has directed attention towards the epoxidation of vegetable oils for biopolymer and plasticizer production. This study investigates the use of natural zeolite as a heterogeneous catalyst in the epoxidation of cooking oil via the in situ peracids mechanism. The epoxidation was carried out using hydrogen peroxide and formic acid at 80°C, with varying catalyst loadings to examine their effect on oxirane yield and reaction kinetics. The oxirane oxygen content (OOC) was monitored through titration, while Fourier Transform Infrared Spectroscopy (FTIR) confirmed structural changes in the oil. Results showed that 0.25 g of natural zeolite yielded the highest relative conversion to oxirane (RCO) of 68.6% within 10 minutes, with higher catalyst amounts resulting in lower efficiency due to possible side reactions. FTIR analysis revealed the successful conversion of unsaturated fatty acids into epoxides, as indicated by the disappearance of alkene (C=C) peaks and the appearance of epoxy (C-O-C) peaks. The study confirms the catalytic potential of natural zeolite as a greener and reusable alternative to conventional homogeneous catalysts, supporting sustainable practices in bio-based chemical processes.
Z-Scheme CoPi/Ag₃PO₄ via Microwave Irradiation for Photodegradation of Rhodamine B
The widespread use of synthetic dyes in the textile industry has led to severe water pollution, as most dyes are not firmly bound to fabrics and are released into aquatic ecosystems. Unchecked release of untreated dye-bearing effluents critically risks environmental quality and human health. Photocatalytic degradation is considered one of the best and most eco-friendly methods employed to degrade dye pollutants from wastewater. In the present study, a Z-scheme photocatalyst, cobalt phosphate (CoPi) and silver phosphate (Ag₃PO₄), abbreviated as CoPi/Ag₃PO₄, was synthesized by a microwave irradiation method for the photodegradation of Rhodamine B (RhB) dye under visible light. The as-synthesized photocatalysts were characterized by field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activity was evaluated using a dosage of 0.375 g/L of catalyst in irradiation for 60 minutes. The 5% CoPi/Ag₃PO₄ showed the highest degradation efficiency at 96%, followed by 10% CoPi/Ag₃PO₄ (92%), Ag₃PO₄ alone (87%), 1% CoPi/Ag₃PO₄ (82%), 15% CoPi/Ag₃PO₄ (73%), and CoPi alone (71%). The enhanced activity of 5% CoPi/Ag₃PO₄ was explained in terms of the homogeneous distribution of the Co and P elements on Ag₃PO₄ and the reduced band gap, which favors better absorption and separation of light. Further studies on the effect of different operating conditions, including initial pH, RhB concentration, and catalyst dosage, were conducted. The optimal degradation was achieved at pH 9, 10 mg/L of RhB, and a catalyst dosage of 0.375 g/L. Scavenger experiments indicated that photogenerated holes (h⁺) were the major contributors to the mechanism of degradation. Finally, microwave-assisted CoPi/Ag₃PO₄ synthesis is a simple and efficient route to produce visible-light-responsive photocatalysts. Doping CoPi significantly enhanced the photocatalytic activity of Ag₃PO₄, and the composite is a promising material for the degradation of dye-contaminated wastewater
Removal of Heavy Metals from Wastewater Using Albizia Lebbeck Seed-Based Activated Carbon
Water, a vital resource for sustaining life, is increasingly threatened by pollution caused by industrialization, population growth, and modernization. This study evaluates the potential of Albizia lebbeck seed-based activated carbon for the removal of Chromium VI [Cr(VI)] ions from aqueous solutions. The Albizia lebbeck seed was chemically modified using 1 M phosphoric acid into activated carbon and examined based on contact time, adsorbent dosage, temperature, concentration, and pH of the wastewater. The efficiency of the preparation was evaluated using batch adsorption isotherm, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), and Energy Dispersive X-ray Spectroscopy (EDS). Batch adsorption results revealed that the removal of Cr (VI) ions from its aqueous solution on the studied adsorbents was influenced by the investigated parameters in varying degrees. The adsorption process was found to be endothermic and best described by the Freundlich as determined from isotherm modelling. The FTIR analysis also established the presence of more surface functional groups and sharper peaks in the activated adsorbent than the original form. The SEM microgram revealed the morphology of the prepared activated adsorbent and The activated adsorbent exhibited higher BET surface area (336.436 m2/g), pore volume (0.305 cc/g), and pore size (6.602 nm), enhancing its mesoporous nature compared to the unmodified adsorbent (236.617 m2/g), (0.215 cc/g) and (6.214 nm) which likely improved its performance. The results confirm that activated Albizia lebbeck seeds are effective adsorbents for removing chromium (VI) ions from aqueous solutions, particularly when treated with inorganic acid. This highlights their potential for removing heavy metal contaminants from industrial wastewater. KEYWORDS Adsorbent, Heavy metals, Activated carbon, Wastewater, Chromium.
Preparation of Mesoporous Al-MCM-41 and Its Application for Hydrocracking Cerbera Manghas Oil
Mesoporous Al-MCM-41 was successfully prepared by hydrothermal method over CTABr template. The catalyst was varied of stirred during the synthesis process, with 4 and 8 h. The results obtained showed that Al-MCM-41 with 4 h stirring had a surface area of 184.8508 m2/g and an 8 h stirring of 655.4759 m2/g. The Al-MCM-41 was used as a catalyst for hydrocracking cerbera manghas oil. Based on GC-MS analysis, the products contain 1-methyl-indan (C10H12), cyclotetracosane (C24H28) when using Al-MCM-41 4h. Meanwhile, when using Al-MCM-41 8h catalysts, the products contain 1,3 tetradecadiene (C14H26), and 1-tetracosene (C24H28). All products still contain high oxygenate compounds. The presence of carboxylic acids indicates that the hydrogenation reaction has required high temperature to convert them into biofuel. The results demonstrated that the synthesized Al-MCM-41 had potential applications as catalyst in the hydrocracking of non-edible oil to produce biofuel.
Biomass-based Sorbents for Oil spill Clean-up: A review
The pervasive environmental and health impacts of oil spills, stemming from the extraction, transportation, and handling of crude oil, highlight an urgent need for sustainable remediation techniques. Traditional cleanup methods such as oil skimming, combustion, and synthetic sorbents are often limited by high costs, non-biodegradability, and potential environmental risks. As oil spills continue to rise with global oil consumption, sustainable, eco-friendly alternatives are essential. This review evaluates biomass-based sorbents, particularly agricultural fibres, as promising substitutes for synthetic materials. These natural sorbents exhibit high oil sorption capacities, are biodegradable, and possess hydrophobic properties that enable effective oil retention while repelling water. Their low cost, availability, and potential for reuse through carbonization also position them as economically viable and environmentally responsible solutions. Carbonized biomass sorbents produce biochar, a porous material applicable in wastewater treatment and soil conditioning, contributing to resource circularity and aligning with sustainability goals. Through an analysis of recent advancements, sorption efficiencies, and environmental impacts, this review assesses biomass-based sorbents’ potential to reduce environmental degradation and enhance waste management, underscoring their role in supporting a circular economy approach for oil spill cleanup.
Enhancing Nickel-Based Catalysts for Hydrodeoxygenation: The Role of Sulfated and Phosphated Silica Supports
The development of efficient catalysts for hydrodeoxygenation (HDO) is crucial for producing sustainable hydrocarbons from biomass-derived feedstocks. In this investigation, silica (SiO2) supports were modified through sulfation and phosphatization treatments to enhance the performance of nickel-based catalysts for HDO reactions. The modified silica supports, SiO2-S (sulfated) and SiO2-P (phosphated), were characterized using XRD, FTIR, N₂ physisorption, and FE-SEM techniques to assess their structural changes, surface area, and nickel dispersion. SiO₂-S exhibited the highest surface acidity and pore volume, resulting in superior nickel dispersion and smaller particle sizes. The catalytic performance was evaluated in HDO reactions, with Ni/SiO₂-S achieving the highest hydrocarbon selectivity (89.3%), particularly for C17 hydrocarbons, attributed to the enhanced Brønsted acid sites. Ni/SiO₂-P also improved hydrocarbon production compared to untreated SiO₂, albeit with lower selectivity. This research elucidates the critical role of surface acidity and support modification in optimizing nickel-based catalysts for HDO reactions.
Photocatalytic Degradation of Phenol from Textile Wastewater Using Rutile and ZnO-NPs Doped Rutile Nanocomposite
This research focuses on the photocatalytic degradation of phenol from textile wastewater. The objective is to synthesize and characterize zinc oxide nanoparticles and a rutile-ZnO nanocomposite and compare their degradation performance on phenol from textile wastewater. Zinc oxide nanoparticles (ZnO-NPs) were synthesized via a green method by mixing zinc nitrate hexahydrate with Mangifera indica leaf extract. The synthesized nanoparticles were incorporated into rutile (TiO2), a photocatalyst often limited by its band gap and high recombination rate, to obtain the rutile-ZnO-NPs nanocomposite. The particle size distribution of the synthesised ZnO-NPs was assessed using dynamic light scattering (DLS) and the morphology, surface area of ZnO-NPs, pure rutile, and the rutile-ZnO-NPs nanocomposite were determined using scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The photocatalytic potential of rutile and rutile-ZnO-NPs to degrade phenol from textile wastewater was investigated under three conditions: sunlight, UV lamp, and darkness. The SEM results revealed that the materials have good morphological properties, and the BET results indicated that the synthesised material have relatively large surface area. The rutile-ZnO-NPs demonstrated superior photocatalytic activity under sunlight and artificial light, with degradation efficiencies of 94.87% and 91.66%, respectively, compared to pure rutile's 86.70% and 83.54%. The kinetics of phenol degradation followed pseudo-second order model suggesting chemisorption involving valence forces by sharing or exchanging electron. The doping of ZnO-NPs into rutile matrix enhanced the photocatalytic activity of the nanocomposite.
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An Insight into the Performance and Prospect of Catalysts in Biodiesel Production, with Special Emphasis on Heterogeneous Based Catalysis
Fossil fuel depletion, increased world energy demand, and the environmental crisis linked to petroleum-based energy instigated the quest for its substitute. The sustainability of biodiesel affords it a high prospect over fossil fuels. It has been receiving attention as a result of its biodegradability, renewability, low toxicity, and good transport and storage properties. The main shortcomings of biodiesel are the production cost and choice of catalyst. Three types of catalysts mainly used for biodiesel production are basic, acidic, or enzyme. Industrial production of biodiesel typically employed homogeneous catalysts due to their ability to facilitate the reaction quickly. However, catalyst separation and biodiesel purification are tormenting, requiring a large amount of water. Thus, heterogeneous catalysts, with several advantages over homogenous catalysts, have been searched. Heterogeneous catalysts can be separated from the products effortlessly, thus allowing for recycling. Furthermore, the process is simpler, cheaper, and more environmentally benign. This review aims to evaluate the performance of different types of catalysts in the transesterification reaction, with special emphasis on heterogeneous base catalysts. The review also gives insight into the key catalytic properties that need to be tailored economically and eco-friendly to reduce cost, to give better biodiesel yield/conversion. Additionally, the various conditions necessary for the optimum yield of biodiesel have also been explored. Lastly, the future challenges and prospects of heterogeneous base catalysts are proposed. Keywords: Biodiesel, Catalyst performance, Heterogeneous catalyst, Transesterification
Characterization and Performance Test of Sulfonated Activated Carbon as a Catalyst in the Levulinic Acid Production Process from Cellulose
The production levulinic acid from cellulose was investigated using active carbon as catalyst. This research conducted the characterize of activated carbon, sulfonated activated carbon, and nickel impregnation into sulfonated active carbon. The results showed that the acidity of the active carbon catalyst is 1233.046 μmol/g, while the Ni/sulfonated activated carbon had the highest catalyst acidity of 6106.512 μmol/g. In addition, the highest acidity of the sulfonated activated carbon catalyst was obtained at a sulfonation temperature variable of 150℃ and a H2SO4 concentration of 10 N is 5108.332 μmol/g. At a sulfonation temperature that is too high, degradation of the -OH functional group occurs and can damage the pore structure of the active carbon. The results of FTIR analysis show that in the sulfonated activated carbon catalyst, the S-O, S=O, and C-S groups appear at wavelengths of 748-883 cm-1, 1148 cm-1, and around 600 cm-1 respectively, which proves that the sulfonic acid group successfully attached to the surface of the sulfonated carbon catalyst. Meanwhile in Ni/sulfonated active carbon, the Ni2+ peak appears at a wavelength of 473 cm-1. XRD patterns of the three variables, indicating that sulfonation does not affect the carbon microstructure. The appearance of a new peak at 43° indicates the presence of NiO species in Ni/sulfonated active carbon and the sharper peaks in Ni/sulfonated active carbon indicate that there has been a change in the amorphous area to crystalline, which proves that Ni metal is not only attached to the surface but has entered the active carbon structure. Catalyst performance test show that hydrothermal cellulose without catalyst produces a cellulose conversion of 12% while active carbon catalyst produces a cellulose conversion of 20%. The results of the catalyst performance test also show that hydrothermal cellulose using sulfonated activated carbon produces a conversion of 30% due to the presence of -COOH, -OH, and -SO3H functional groups which have the power to adsorb cellulose so that it is efficient for the cellulose hydrolysis reaction. The highest cellulose conversion of 42% was achieved when using Ni/ sulfonated active carbon due to the presence of Ni which bound to the sulfonate groups enhanced the acidity and catalytic activity.
Direct Alcoholysis of Glucose into Alkyl Levulinates Catalysed by Metal-Doped Sulfonated Activated Carbon
Lignocellulosic biomass is widely studied to produce alkyl levulinate through alcoholysis catalysed by acid catalyst, which potentially used as a biofuel additive. However, the poor properties of homogeneous catalyst have prompted this study to focus on enhancing the yield of alkyl levulinate by using sulfonated activated carbon (AC-S) doped with different metals as a heterogeneous catalyst with co-existence of Brønsted and Lewis acidic sites. The activated carbon (AC) precursor was modified via sulfonation and impregnated with iron (Fe), copper (Cu) and cobalt (Co) metals, which were further characterised to evaluate their physicochemical properties as a catalyst. Their catalytic activity was evaluated for glucose alcoholysis in a stainless-steel batch reactor at 180 ˚C for 4 h, by charging 0.6 g of glucose, 40 mL of alcohol (methanol and ethanol) and 0.3 g of catalyst. From the result, the catalyst properties were improved after sulfonation and metal doping. Among the employed heterogeneous catalysts, AC-S-Cu exhibited the highest catalytic activity, which was contributed mainly by its co-existence of Brønsted and Lewis acidic sites with significant Brønsted acidity, higher thermal stability with minimum weight loss up to 200 ˚C (<2 wt%), better morphology, and larger surface area (928 m2/g). The maximum alkyl levulinate yield (15.04 wt%) was obtained for ethyl levulinate production under conditions of 180 ˚C, 4 hr, 0.6 g of glucose, 0.3 g of AC-S-Cu and 40mL of ethanol. The outcome of this study provides an insight on the potential of AC-S-Cu in facilitating the direct alcoholysis of glucose to alkyl levulinate
Synthesis and Characterization of Fe2O3/g-C3N4 Photocatalyst from Waste Toner Powder
Modern use of electrical and electronic equipment and the rapid development of technologies lead to the production of electronic waste. Electronic waste management is one of the key challenges for the green revolution without affecting the environment. One of the electronic wastes includes toner powder from the printer. Toner powder consists of polymer, carbon black, Fe3O4, additives and charge control agents. This paper focuses on the synthesis and characterization of Fe2O3/g-C3N4 photocatalyst. Initially, waste toner powder was calcined at 600 °C at air atmosphere to ensure the complete decomposition of organic residues. Then the obtained Fe2O3 was mixed with g-C3N4 by polycondensation method for fabrication of Fe2O3/g-C3N4 photocatalyst. The obtained Fe2O3, g-C3N4 and Fe2O3/g-C3N4 were characterized by FTIR, SEM and TGA. FTIR and SEM results confirm that Fe2O3 is successfully incorporated with g-C3N4 while TGA analysis demonstrates an excellent thermal stability for Fe2O3/g-C3N4 photocatalyst. The physicochemical properties of Fe2O3/g-C3N4 catalyst demonstrated its ability to be utilized in a variety of photocatalytic reactions. Therefore, the utilization of waste toner powder as an iron (Fe) precursor may offer a great opportunity for waste management and the fortification of the environment such as in wastewater treatment.
Environmental Influences on Microplastics and Particulate Matter Resuspension in Indoor Air: A Study of Office Settings with Air Conditioning
This study investigates airborne microplastics (MPs) in office environments, with a particular focus on spaces with air conditioning (AC), due to increasing health concerns. The research aims to analyze the physical characteristics, sources, distribution, and potential health risks of MPs. Despite growing awareness of MP pollution, comprehensive data on their specifics in office settings—such as shape, composition, and size—remains limited. Between November 2023 and January 2024, 42 air samples were collected under controlled conditions, both with and without AC, at the Air Resource Research Laboratory, Universiti Teknologi Malaysia Kuala Lumpur Campus. Stereomicroscopy was employed to identify the MPs’ physical properties, revealing a dominance of bead-shaped MPs in air-conditioned spaces, with smaller particles (<50µm), often transparent or black, being the most prevalent. Environmental factors like wind speed and humidity were found to influence MPs' abundance. The study also noted a potential correlation between atmospheric MPs and particulate matter (PM) emissions, suggesting shared sources or accumulation mechanisms. Estimates of daily MPs intake through dust ingestion highlighted associated health risks. This research provides insights into the dynamics of MPs and PM in air-conditioned offices, emphasizing the need for further investigation into their environmental and health impacts. Effective mitigation strategies are crucial for reducing MP and PM exposure, thereby improving indoor air quality and protecting human health.
Evaluation of the Glass Transition Temperature and Intermolecular Interaction of Poly(ethylene oxide) with Addition of Lithium Perchlorate or/and Titanium Dioxide
The high crystallinity of poly (ethylene oxide) (PEO) has urged the need for adding salt or nanofiller. The effect of the glass transition temperature (Tg) and intermolecular interaction of PEO upon the addition of salt or nanofiller become a debatable topic due to the lacking of the understanding of the role of salt or nanofiller in PEO. Hence, the evaluation of the Tg and intermolecular interaction of PEO with addition of lithium perchlorate (LiClO4) salt or/and titanium dioxide (TiO2) nanofiller are presented and discussed. The solid polymer electrolytes with addition of nanofiller are prepared by solution casting technique. The optimum composition of PEO and LiClO4 salt is used as host matrix and TiO2 as nanofiller. The Tg and intermolecular interaction of the polymer-based electrolytes have been studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. PEO-LiClO4 serves as the classical model of polymer-salt systems with good polymer-salt molecular interaction at low salt concentration (WS ≤ 0.107) whereas TiO2 without any surface treatment when added to PEO, serves as a classical model of polymer-nanofiller systems with weak polymer-nanofiller molecular interaction. Results have shown that LiClO4 salt gives notable effect on the Tg and intermolecular interaction of PEO. Whereas, TiO2 do not provide a substantial effect on the Tg and intermolecular interaction of PEO-based polymer electrolytes. This work provides a better understanding and knowledge of the effect of addition of salt or/and nanofiller in the Tg and intermolecular interaction of the PEO systems.
Enhancing Aerobic Granular Sludge Formation in Domestic Wastewater Through Mg2+ Augmentation
This study investigates the optimal Mg²⁺ concentration for enhancing aerobic granular sludge formation in domestic wastewater treatment. Domestic wastewater samples and activated seed sludge were obtained from a local wastewater treatment plant. The research examined three Mg²⁺ concentrations—130 mg/L, 160 mg/L, and 260 mg/L—alongside a control sample without Mg²⁺. Each sample was supplemented with solid magnesium sulfate (MgSO₄) before being fed with activated seed sludge for aerobic granular sludge cultivation in four lab-scale sequential batch reactors, operated at a 50% volume exchange ratio (VER) and a 2.5 L/min aeration rate. Results indicated that a 160 mg/L Mg²⁺ concentration yielded the highest chemical oxygen demand (COD) removal efficiency and stable granule formation within a 20-day cultivation period. In contrast, Mg²⁺ concentrations exceeding 260 mg/L negatively impacted aerobic granular sludge formation due to altered extracellular polymeric substance (EPS) content. This study identified 160 mg/L as the optimum Mg²⁺ concentration for efficient granular sludge formation, showing promising potential to improve existing practices in wastewater management.
Biocomposite Material Using Sugarcane Bagasse and Modified Starch for Potential Packaging in Agroindustry
The widespread use of petroleum-based plastics in packaging has raised significant environmental concerns due to their non-biodegradability and detrimental ecological impacts. This study explores the development of an eco-friendly biocomposite material using sugarcane bagasse and cassava starch as potential alternatives for agro-industry packaging. The research objectives include characterizing the morphological properties of modified and unmodified sugarcane bagasse, analysing the thermal and physical properties of the resultant biocomposite, and evaluating its potential as a sustainable packaging material. A set of samples experiment were investigated using a constant ratio of distilled water to cassava starch which is 3:1 and 5 different ratios of acetic acid to bagasse. The morphological properties of biocomposite material which are sugarcane bagasse and cassava starch were examined using a Field-Emission Scanning Electron Microscope and Fourier Transmission Infrared Spectroscopy. Thermogravimetric Analysis (TGA) and Tensile strength were used to analyse thermal and physical property. Subsequently, the assessment of environmental friendliness was conducted by biodegradability testing. The results indicate that the most optimal biofilm, in terms of flexibility, thermal stability, and decomposition speed, was achieved with a ratio of (2:1) and (3:1) of acetic acid to bagasse. The results obtained suggest that sugarcane bagasse, when combined with cassava starch, can serve as an effective, biodegradable packaging material, potentially mitigating the environmental impact of conventional plastics in the agro-industry.
Effect of Tea Waste Extract Volume on Synthesis of TiO2 for Photodegradation of 2,4-dichlorophenol
The volume effect of tea waste extract was studied in synthesis of titanium dioxide (TiO2) namely TiO2-1 (1 mL), TiO2-3 (3 mL) and TiO2-5 (5 mL). The catalysts were characterized by XRD, FTIR, BET, UV-Vis DRS and FESEM. The role of tea waste extract in formation of TiO2 was tested to degrade 2,4-dichlorophenol (2,4-DCP) under visible light irradiation. The best photocatalytic degradation of 2,4-DCP was achieved using TiO2-1 (85%) compared with TiO2-3 (80%), TiO2-5 (77%) and P25 (71%). Furthermore, the optimum volume of tea waste extract was 1 mL and the results show that increasing volume of tea extract increased the band gap and crystallite size, while the surface area was decreased. The role of tea waste extract as capping agent in synthesis of TiO2 contributed significantly to the good photocatalytic degradation of 2,4-DCP.
Catalytic deoxygenation of Reutealis trisperma oil over Al-MCM-41 derived from red mud
The Al-MCM-41 was successfully synthesized from red mud as silica and alumina source. The synthesis process involved a two-step hydrothermal method using CTABr as the mesopore template. The XRD analysis shows an amorphous structure characteristic of Al-MCM-41 with uniform hexagonal pore structure. The resulting Al-MCM-41 had a high surface area of 461.37 m2/g with the high pore volume of 0.41 cc/g. Morphologically, the Al-MCM-41 catalyst displayed agglomerated small crystallites with particle sizes ranging from 0.6 to 1.4 μm. Elemental analysis showed the catalyst comprised Al, Si, Fe, and O elements, with percentages of 5.45%, 39.61%, 2.72%, and 49.09%, respectively. The catalyst was used in the catalytic deoxygenation of Reutealis trisperma oil to produce diesel-range hydrocarbon. Furthermore, GC-MS analysis of the liquid product demonstrated a selectivity of 48.5% for hydrocarbons and 28.14% of aromatic.
Effect of Transition Metal/Graphitic Carbon Nitride for Photoreduction of Hexavalent Chromium
Recently, the discharge of heavy metals such as hexavalent chromium (Cr(VI)) into water is increasing due to the development of industrials. This poses a huge environmental challenges as toxic waste of heavy metal leads to water pollution which give a negative impact on health and environment. This heavy metal can be treated by reducing the highly poisonous of Cr(VI) to less toxic trivalent chromium Cr(III). Nowadays, the photocatalytic reduction is one of the effective method that can reduce Cr(VI) to harmless toxic into the environment. In this study, the effect of different metal of Ag, Cu and Ni loaded on g-C3N4 were investigated based on the structural, morphological, compositional, and optical properties. The different metal of Ag, Cu and Ni were loaded on g-C3N4 by using impregnation method. The physical and chemical properties of Ag, Cu and Ni loaded on g-C3N4 were analyzed using FTIR and UV-vis/DRS techniques. The performance of photocatalytic activity among Ag, Cu and Ni loaded on g-C3N4 were evaluated for photoreduction of Cr(VI) and the highest performance of photoreduction of Cr(VI) was demonstrated by Ag/C3N4 (87%), followed by Cu/C3N4 (85%), Ni/C3N4 (80%) and pure g-C3N4 (77%) under visible-light. Among of photocatalyst, Ag/C3N4 was revealed as the best performance in photoreduction of Cr(VI) owing to its change in morphology, strong interaction between Ag and C N bonds and low band gap. Besides, the effect of scavengers shows the active species was the photogenerated electron (e-) play an important role on photoreduction of Cr(VI). Overall, the Ag loaded on g-C3N4 was successfully contribute on photoreduction of Cr (VI) under visible light.
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Luffa Cylindrica Fibers Unveiled: A Sustainable Approach for 4-Nitrophenol Removal in Aqueous Solutions through Activated Carbon Utilization
The prevalence of mutagenic and highly toxic compounds, such as 4-Nitrophenol (4-NP) and its derivatives, in industrial wastewater poses a significant environmental threat. This study emphasizes the critical need for public authorities to prioritize combating organic compound pollution for achieving sustainable development. The focus of this research is the preparation and evaluation of activated carbon adsorbents derived from Luffa cylindrica fibers (LC) for the efficient removal of 4-NP from aqueous solutions. The preparation involved carbonization process by heating LC in an argon furnace at 800℃, resulting in carbonized Luffa cylindrica fibers (LCC). Subsequently, chemical activation is performed using potassium hydroxide (KOH) solution, denoted as LCA. The properties of the adsorbent are identified through X-Ray Diffraction (XRD). To assess the removal efficiency of 4-NP, various parameters such as pH, adsorbent dosage, and 4-NP solution concentration are investigated. Optimal conditions for maximum 4-NP removal are achieved at a concentration of 50 mg/L, an adsorbent dosage of 0.75 mg/L (LCA), and a solution pH of 5. These conditions result in an impressive 99 % removal of 4-NP in 60 minutes. This study demonstrates the feasibility of utilizing locally available raw materials, such as LC fibers, to prepare an adsorbent with a robust adsorptive capacity for toxic pollutants like 4-NP. The findings underscore the potential of eco-friendly solutions in addressing environmental challenges and promoting sustainable practices in wastewater treatment.
EXPERIMENTAL STUDY OF THE PRESSURE DROP AND FLOODING IN A ROTATING PACKED BED REACTOR
In conventional packed beds, mass transfer and flooding limitations lower the productivity of many processes. The almost zero sensitivity to variations in gravitational force has made centrifugal processes to have great potential for enhancing heterogeneous catalytic reactions. We studied a rotating packed bed (RPB) reactor as a gas/liquid contactor for multi-phase catalytic reactions. The scarcity of fundamental data on the hydrodynamics and mass transfer of the reactor limits the design, scale-up, and retrofitting of RPB reactors. Hence, we focused on the hydrodynamic behavior of the device. Previous studies on RPB reactor flooding and operating limits dwelled on visual observations and pressure drop variations only. However, physical visualizations are subjective because RPB reactor pressure drop variations are too inconsistent to be used to determine the upper operating limit during their operations. A robust quantitative method of obtaining RPB reactor flooding limits based on the flow rate of the ejected liquid, supported by visual observation and pressure drop measurement, was presented. The aim was to identify, with greater certainty, RPB reactor hydrodynamic characteristics and provide a more standard method of identifying it. The average increase in single-phase pressure drop per unit increase in rotation speed in the range investigated was 0.75Pa/rpm, and the average increase in pressure drop per unit increase in gas flow rate was 4.11Pa/Nm3h-1 within the operating range investigated.
Extraction and Characterization of Keratin Protein from Chicken Feathers using Alkaline Hydrolysis Method: Effects of Sodium Sulphide Concentration and Shelf-life Evaluation
This study investigated the extraction of keratin protein from chicken feathers through alkaline hydrolysis using sodium sulphide as a digesting agent. The protein was precipitated using hydrogen chloride and confirmed through biuret test, solubility test, sulfur test, and FTIR analysis. The effect of varying sodium sulphide concentrations (0.5 M, 0.75 M, and 1 M) on the extracted keratin was evaluated. Results showed that a higher concentration of sodium sulphide produced a higher yield of keratin, with 1 M producing 65.8% yield. However, the shelf-life of wet keratin extracted using 1 M concentration was four weeks, compared to six weeks for 0.5 M and 0.75 M concentrations. The dried keratin was unaffected after six weeks. The study suggests that a higher concentration of the reducing agent produced a higher yield of keratin protein but with a shorter shelf-life if drying was not carried out. The utilization of abundant waste generated by poultry industries is crucial in reducing pollution and creating opportunities for valuable product development. The extraction of keratin from chicken feathers provides an eco-friendly approach to waste management and creates opportunities for product development.
Effect of Ni/Al-MCM-41 Impregnation Method on Catalytic Deoxygenation of Reutealis Trisperma Oil
Deoxygenation of Reutealis trisperma oil into green diesel has been carried out using Ni/Al-MCM-41 catalyst. The Ni/Al-MCM-41 catalyst was prepared using the wetness impregnation and incipient wetness impregnation methods, hereinafter referred to as Ni/Al-MCM-41 (WI) and Ni/Al-MCM-41 (IWI). XRD and FTIR analysis shows a characteristic of amorphous phase for solid Al-MCM-41 catalyst. FTIR pyridine was used to assess the impact of the NiO impregnation technique on Lewis acid and Brønsted acidity. The acidity test showed that the Ni/Al-MCM-41 (WI) catalyst had the highest total acidity 0,227 mmol/g. The catalytic activity of Ni/Al-MCM-41 catalyst was examined in deoxygenation reaction of Reutealis trisperma oil under inert conditions for 4 hours. In comparison to Ni/Al-MCM-41(IWI) and Al-MCM-41 catalysts, the Ni/Al-MCM-41(WI) catalyst produced better results in the deoxygenation reaction of Reutealis trisperma oil with a selectivity of hydrocarbon compounds (C11-18) of 100% and a degree of deoxygenation of 92.77%.
ORANGE PEEL WASTES AS LOW-COST ADSORBENT FOR REMOVAL OF NICKEL AND CHROMIUM IN AQUEOUS SOLUTION
Agricultural-by products such as orange peel (OP) was found to be abundant in quantity and had great components to adsorb the heavy metals. In this study, orange peel was used as biosorbent in adsorption process of heavy metal. The main aim of this study was carried out to examine the ability of adsorbents orange peel to remove nickel, Ni(II) and chromium, Cr(VI) ions from aqueous solution. From literature review, orange peel was proven can adsorb considerable quantities of Ni(II) and Cr(VI) ions in aqueous solution. The adsorption of Ni(II) and Cr(VI) ions were conducted in batch experiment to investigate the different parameters which are the effect of contact time, pH, adsorbent dosage and initial Ni(II) and Cr(VI) concentration. the optimum conditions for Cr(VI) were achieved when using 1.5 g of acid-treated orange peel at pH 3 in 20 ppm of initial Cr(VI) concentration which successfully removed 47.45% of Cr(VI) from aqueous solution within 90 min of contact time. The optimum conditions for Ni(II) were achieved when using 1.0 g acid-treated orange peels at pH 7, with 40 mg/L of initial Ni(II) concentration which removed 83.85% Ni (II) from aqueous solution within 90 min of adsorption time. Statistical analysis showed that that there was a significant mean different between percent removal of heavy metal adsorb by raw and acid-treated corncobs. However, there is no significant relationship between dosage and percent removal of Cr(VI) from aqueous solution. Therefore, raw and acid-treated orange peel certainly can remove Ni(II) and Cr(VI) ions from aqueous solution.
Understanding the effect of the calcination process on the structure of mesoporous silica zirconia photocatalysts for Bisphenol A degradation
The mesoporous silica zirconia (m- SiO2/ZrO2) was successfully synthesized in this study using a microwave method, and the effect of the calcination process was studied. In this study, half of the sample was left untreated (labeled "untreated sample"), while the other half was calcined at 850 °C for 3 hours in an air atmosphere in a muffle furnace to remove the surfactant. X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible differential reflectance spectroscopy, nitrogen adsorption-desorption spectroscopy, and electron spin resonance spectroscopy were utilized in order to analyze the catalysts that were produced. The findings from the characterization showed that the calcination procedure caused the creation of oxygen vacancies and increased the surface area, both of which affected the photocatalytic activity. The photocatalytic activity of the calcined m-SiO2/ZrO2 (80%) catalyst was superior to that of the untreated m-SiO2/ZrO2 (19%) catalyst. Zirconia's greater surface area and its natural occurrence in the tetragonal phase are both to blame for this phenomenon. In addition, there is the possibility that a greater proportion of oxygen vacancy will result in a smaller band gap and a lower electron-hole recombination rate. After five cycles, the photocatalytic activity exhibited by both catalysts remained unchanged.