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Treatment of oil pollution remains a challenge due to the growing urbanisation. Thus, there is an increasing number of global studies on exploiting simple and effective methods to remove oil from water. In the present work, spent tea leaves (STL) have been modified using oleic acid (OA) and free fatty acids from waste cooking oil (FFA-WCO). The aim was to enhance the hydrophobicity of the STL so that they can act as an oil adsorbent. The functional groups of the fatty acids within the modified STL were identified using the Fourier Transform Infrared (FTIR) Spectroscopy analysis, while the surface morphology of STL was characterised using a Scanning Electron Microscope (SEM). The performance of the synthesised adsorbents for oil adsorption was tested in batch adsorption experiments. The FTIR results revealed that free fatty acids have been successfully impregnated onto the surface of STL. SEM analyses showed that the surface of the fatty acid-modified STL has smoother surfaces compared to the rougher surface of unmodified STL. From the batch adsorption test, the highest adsorption capacity was observed using 1:10 ratio of STL to WCO, with 120 min of contact time, 1 g of adsorbent dosage, and under the temperature of 45 °C. The adsorption capacity of STL@FFA-WCO at the optimum condition was 1.800 ± 0.15 g/g. For the effect of modification agents, STL that were modified using oleic acid (STL@OA) showed greater adsorption capacity of 2.267 ± 0.21 g/g. These findings proved that the fatty acid-modified STL have the potential of becoming green adsorbents for oil removal.

Heterogeneous photocatalysis is one of the popular alternative treatment methods for wastewater. It utilizes semiconductor material as the catalyst and metal oxide such as zinc oxide nanoparticles (ZnO NPs), emerged as the commonly used catalyst. In this study, a series of biogenic ZnO NPs was fabricated through precipitation method with pullulan as the biomaterial. The amount of zinc salt in the presence of pullulan was varied to study its impact on the generated ZnO NPs. The results showed that without pullulan, the average particle size of ZnO NPs obtained was 110.86 nm. With 0.84 M zinc salt in 50 g/L of pullulan, the ZnO NPs average particle size significantly reduced to 58.13 nm. The surface area of all synthesized ZnO NPs ranging from 14.84 to 19.99 m2 g−1. The photocatalytic activities of all synthesized ZnO NPs were evaluated through the photodegradation of two drugs, amoxicillin (AMX) and paracetamol (PCT). Through the comparison of drugs’ photodegradation with all synthesized ZnO NPs, ZnO NPs produced with 0.67 M zinc salt in 50 g/L of pullulan showed the highest degradation percentage of 85.7% and 96.8% for AMX and PCT respectively. The best photodegradation conditions for the drugs were 30 ppm drugs concentration, pH 9 (for AMX) and pH 5 (for PCT) and 50 mg catalyst dosage. Based on these results, biogenic ZnO NPs has high potential to be used in the treatment of pharmaceutical wastewater.

Water pollution is one of the major problems faced by mankind worldwide. With the increase of populations and urbanization, the natural water resources are under great threat due to the release of untreated effluent. An alternative treatment method, photocatalysis, emerged as a promising solution. Photocatalysis process utilizes photosensitive catalyst to degrade the pollutant and one of the most common catalyst being used is metal oxide. To increase the photocatalytic activity, nanosized metal oxide being used instead of its bulk form. In these recent years, metal oxide nanoparticles production has been shifted towards a more environmentally friendly process which is also commonly known as green synthesis. In this review, we discussed on the photocatalytic process and production via green synthesis of common metal oxide nanoparticles being used as photocatalyst.

Fewer fossil fuel deposits, price volatility, and environmental concerns have intensified biofuel-based studies. Saccharification, gasification, and pyrolysis are some of the potential methods of producing carbohydrate-based fuels, while lipid extraction is the preferred method of producing biodiesel and green diesel. Over the years, multiple studies have attempted to identify an ideal catalyst as well as optimize the abovementioned methods to produce higher yields at a lower cost. Therefore, this present study comprehensively examined the factors affecting biodiesel stability. Firstly, isomerization, which is typically used to reduce unsaturated fatty acid content, was found to improve oxidative stability as well as maintain and improve cold flow properties. Meanwhile, polymers, surfactants, or small molecules with low melting points were found to improve the cold flow properties of biodiesel. Meanwhile, transesterification with an enzyme could be used to remove monoacylglycerols from oil feedstock. Furthermore, combining two natural antioxidants could potentially slow lipid oxidation if stainless steel, carbon steel, or aluminum are used as biodiesel storage materials. This present review also recommends combining green diesel and biodiesel to improve stability. Furthermore, green diesel can be co-produced at oil refineries that are more selective and have a limited supply of hydrogen. Lastly, next-generation farming should be examined to avoid competing interests in food and energy as well as to improve agricultural efficiency.

A simple microwave method was employed to prepare silica-doped mesoporous zirconia nanoparticles, SiO2/ZrO2 (SiZr) catalysts under various Si amount and then characterized by X-ray diffraction, nitrogen adsorption–desorption analyses, Fourier-transform infrared, electron spin resonance, ultraviolet–visible diffuse reflectance spectroscopy and photoluminescence analyses. The lower amount of Si fully stabilized the ZrO2 in the tetragonal phase (t-ZrO2), but the higher amount of Si occupied oxygen vacancies (OV) in the SiZr lattice to disrupt the catalysts with introduce low content of monoclinic phase. The catalyst activity towards on photodegradation of 2-chlorophenol (2-CP) was ranked in the following order: 1SiZr (92%) > TiO2 (73%) > 2SiZr (67%) > 3SiZr (64%) > 4SiZr (56%) > ZrO2 (51%). This result demonstrated that 1SiZr gave the highest degradation percentage of 10 mg L−1 2-CP at pH 5 using 0.375 g L−1 catalyst under visible light irradation within 4 h. The highest photoactivity of 1SiZr is due to the larger surface area and crystallite size, which resulted in a good surface contact with light and thus accelerated the photocatalytic activity. Additionally, the highest amount of OV possesed by 1 SiZr effectively suppressed the electron–hole recombination by acting as an electron acceptors, which consequently affected the t-ZrO2 stabilization as well as the catalytic activity. The kinetics of photocatalytic degradation of 2-CP correlated with pseudo-first order model, with the surface reaction as the controlling step. The photogenerated hole was the most active species as confirmed by effect of scavenger study. The 1SiZr maintained the photocatalytic activities after five runs and has a great capability in degrading of various phenols derivatives, indicating its potential use in the phenol-based wastewater treatment.

The continuous demand for olefins has stimulated recent research to develop appropriate technology to produce olefins from alternative resources. Syngas-to-olefins (STO) is considered to be a promising pathway due to the availability of numerous technologies to produce syngas from municipal solid waste and biomass. The development of catalysts to obtain high CO conversion and high selectivity to olefins is still in progress. The first route is based on iron and cobalt catalysts via Fischer Tropsch synthesis to olefins (FTO) with a range of promising supports and promoters. The second approach is based on metal oxide–zeolite (OX–ZEO) composites, with a focus on combined metal oxides to increase the CO conversion. Finally, the potency of less-explored zeolite frameworks such as FER, KFI and Rho zeolites is highlighted. We propose that researchers should focus on FER, KFI and Rho zeolites. However, further reaction mechanism studies should be elaborated to obtain their optimum conditions for STO.

Thiophene is one of the sulfur compounds in the petroleum fraction that can be harmful to living things and lead to a critical effect on the ecosystem. Photocatalytic degradation is one of the promising methods in treating wastewater as it can mineralization of pollutants into carbon dioxide and water. Other than that, this method is non-toxic and relatively low cost. The production of hydroxyl radicals playing a vital role in the degradation of organic pollutants. It has been claimed that the usage of zinc oxide (ZnO) nanoparticles could give an excellent degradation process as this photocatalyst have high photosensitivity, low cost and chemically stable. However, the preparation method of ZnO nanoparticles will affect the agglomeration, particle size, shape and morphology of particles and lead to influence the photocatalytic activity in degrading thiophene. Therefore, this study focused on the effectiveness of ZnO nanoparticles in the presence of fibrous nanosilica (KCC-1) and polyethylene glycol (PEG) as the capping agent to degrade synthetic thiophene. ZnO/KCC-1 had been synthesized via the precipitation method and characterized by using Fourier Transform Infrared (FTIR). The chemical bond and nature of the photocatalyst from the FTIR results proved that the synthesis process to produce the ZnO/KCC-1 was succeed. The large surface area of KCC-1 increases the effectiveness of ZnO which is supported by the experimental data. Accordingly, the optimum condition for photocatalytic degradation of thiophene is under pH 7 by using ZnO/KCC-1 as photocatalyst. Hence, it is believed that this research could be implemented to remove the thiophene in petroleum fraction from the actual industrial effluents and this can preserve nature in the future.

Advanced extraction method such as simultaneous ultrasonic–hydrodistillation (UAE–HD) extraction method has been proved to increased extraction yield of plant material yet the application of this method in the preparation of metal nanoparticles has not been studied. In this study, Cymbopogon nardus (C.N) extracted via UAE-HD extraction method was used to synthesis silver (Ag) nanoparticles. XRD and TEM analysis confirms the formation of spherical shape Ag nanoparticles with size ranging between 10-50 nm. FTIR spectra suggest the presence of bioactive compounds in the C.N leaves extract that may responsible to the stabilization and reduction of Ag ions (Ag+) to metallic Ag nanoparticles (Ag0). The TPC analysis successfully proved that huge number of phenolic compound greatly involved in the nanoparticles synthesis process. Next, the catalytic activity of the synthesized Ag nanoparticles was tested towards the degradation of 2,4-Dicholorophenoxyacetic acid herbicide with remarkable degradation performance up to 98%. Kinetic study confirms that surface reaction was the controlling step of the catalytic process. Copyright © 2019 BCREC Group. All rights reservedReceived: 1st October 2018; Revised: 12nd November 2018; Accepted: 12nd December 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Kamarudin, N.S., Jusoh, R., Setiabudi, H.D., Jusoh, N.W.C., Jaafar, N.F., Sukor, N.F. (2019). Cymbopogon nardus Mediated Synthesis of Ag Nanoparticles for the Photocatalytic Degradation of 2,4-Dicholorophenoxyacetic Acid. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 173-181 (doi:10.9767/bcrec.14.1.3321.173-181)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.3321.173-181

The utilization of waste heat for heat recovery technologies in process sites has been widely known in improving the site energy saving and energy efficiency. The Total Site Heat Integration (TSHI) methodologies have been established over time to assist the integration of heat recovery technologies in process sites with a centralized utility system, which is also known as Total Site (TS). One the earliest application of TSHI concept in waste heat recovery is through steam turbine using the popular Willan’s line approach. The TSHI methodologies later were extended to integrate with wide range of heat recovery technologies in many literature, whereby Organic Rankine Cycle (ORC) has been reported to be the one of the beneficial options for heat recovery. In general, the medium to high temperature waste heat is recovered via condensing/backpressure steam turbine, whereas ORC is targeted for recovering the low temperature waste heat. However, it is known that condensing turbine is also able to generate power by condensing low grade steam to sub-ambient pressure, which is comparable with ORC integration. In this work, the integration of ORC and condensing turbine are considered for a multiple-process system to recover intermediate temperature waste heat through utility system. This study presents a numerical methodology to investigate the performance analysis of integration of ORC and condensing turbine in process sites for recovering waste heat from a centralized utility system. A modified retrofit case study is used to demonstrate the effectiveness application of the proposed methodology. The performance of ORC and condensing steam turbine are evaluated with the plant total utility costing as the objective function.

An electrochemically reduced graphene oxide was grown on carbon felt surface in a simple one-step electrodeposition process of graphene oxide and it was employed as a positive electrocatalyst of vanadium redox flow battery. The electrodeposited graphene-based nanocomposite on carbon felt presented outstanding electrochemical redox reversibility toward vanadium redox couple. Based on the cyclic voltammetry data and electrochemical impedance spectroscopy curves, the modified composite electrode possesses a huge amount of oxygen functional groups, high surface area, high electrical conductivity and excellent stability in compared to the pristine carbon felt electrode. The prepared electrode showed promising performance for vanadium redox flow battery as the energy efficiency was significantly enhanced by 12% at current density of 60 mA cm−2. This superior performance was probably due to the increase in the surface sites and fast electron transfer rate of the reduced graphene oxide.

A series of magnetite nanoparticles were prepared with electrosynthesis. Natural capping agent, sodium alginate (SA) was added to electrolysis system to produce smaller size and highly crystalline of magnetite. The variation of SA content highly influenced the particle size which confirmed with XRD. FTIR characterization confirmed that SA interact with magnetite surface. The magnetite product was also evaluated for paracetamol (PCT) degradation as a sample of pharmaceutical waste due to its large consumption in society. The highest initial degradation rate (8.22 x 10-2 mg/L.min) was achieved with magnetite which is prepared from 0.05% w/v of SA at initial concentration of 15 mg/L PCT. Finally, the result could contribute to electrosynthesis advancement of magnetite with high purity using inexpensive and green chemicals.

Vanadium Redox Flow Battery (VRFB) is an energy storage flow battery in whichthe key material for VRFB is the membrane that determines the cost and performance of the battery. Porous membranes have shown a great potential as a membrane due to their high stability, cheap and high selectivity. Poly(vinylidine fluoride) (PVDF) is a type of porous membrane that was extensively studied as a potential material for surface modification due to its thermal and chemical stability, inexpensive and mechanical properties. This study aims to develop a highly selective, high-performance modified PVDF membrane using surface grafting and functionalization for VRFB application using the sonication method. Graphene oxide (GO) is a trending material in the field due to its excellent properties such as being highly resistant to alkaline/acidic and strong mechanical strength, low cost and easily accessible. In this work, GO was functionalized on both sides of grafted PVDF using the sonication technique. Hydrogen bond from modification with GO caused the membrane to be a hydrophilic and FTIR results proved that new peaks appeared which relates to carbon bond from GO. Proton conductivity of modified membrane is recorded higher than commercial VRFB membrane, Nafion.

Zinc oxide (ZnO) nanoparticles in the presence of fibrous silica (KCC-1) were produced via simple and green precipitation method. The nanoparticles properties were characterised with Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning electron microscopy (FESEM). It is believed that the preparation method influences on the characterization result. Based on nanoparticles characterisation, the properties of the chemical bond and nature of ZnO/KCC-1 and KCC-1 photocatalyst were analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) that produced an infrared absorption spectrum. While, the morphology, dimension and particle surface area were observed by using Field Emission Scanning electron microscopy (FESEM).

Nickel (Ni), cobalt (Co), and zinc (Zn) loaded on fibrous silica KCC-1 was investigated for CO2 methanation reactions. Ni/KCC-1 exhibits the highest catalyst performance with a CH4 formation rate of 33.02 × 10–2 molCH4 molmetal–1 s–1, 1.77 times higher than that of Co/KCC-1 followed by Zn/KCC-1 and finally the parent KCC-1. A pyrrole adsorption FTIR study reveals shifting of perturbed N–H stretching decreasing slightly with the addition of metal oxide, suggesting that the basic sites of catalyst were inaccessible due to metal oxide deposition. The strengths of basicity were found to follow sthe equence KCC-1, Ni/KCC-1, Zn/KCC-1, and Co/KCC-1. The data were supported by N2 adsorption desorption analysis, where Co/KCC-1 displayed the greatest reduction in total surface area whereas Ni/KCC-1 displayed the least reduction. The elucidation of difference mechanism pathways has also been studied by in situ IR spectroscopy studies to determine the role of different metal oxides in CO2 methanation. It was discover...

The increasing number and concentration of organic pollutants in water stream could become a serious threat in the near future. Magnetite has the potential to degrade pollutants via photocatalysis with a convenient separation process. This study discusses in detail the control size and morphology of magnetite nanoparticles, and their composites with co-precipitation, hydrothermal, sol-gel, and electrochemical route. Further photocatalytic enhancement with the addition of metal and porous support was proposed. This paper also discussed the technology to extend the lifetime of recombination through an in-depth explanation of charge transfer. The possibility to use waste materials as catalyst support was also elucidated. However, magnetite-based photocatalysts still require many improvements to meet commercialization criteria.

In the last several years, the interest on hydrophobic and hydrophilic solid subtract was increased due to many applications in daily life, agriculture and industry. The continuous effort has been made to fabricate suitable material with more efficient fabrication method. In this research, physical blending method have been used by mixing four components of modifying agent with organic beeswax varnish at different weight percentage. Those modifying agents consists of decamethylcyclopentasiloxane (D5), Silica nanoparticles (R812S), Polydimethylsiloxane (BP-9400) and non-ionic surfactant (Triton X-100) were mixed in the mass ratio of 52:3:34:1. The modified varnish produced was coated on Pineapple peel fiber (PAPF) biocomposite and were characterized using Water Contact Angle (WCA) instrument, Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). Based on the wettability index analysis; the value of water contact angle was reduced when increasing weight percent of modifying agents from 101.87 to 22.98°. The morphology of the surface was observed to have more silica nanoparticles, along with the increasing concentration of modifying agent. It also supported by FTIR which shows the presence of Si-O peak at 1030.88 cm-1. These results proved that the modifying agent and organic beeswax varnish had successfully produced hydrophilic coated on the PAPF surface.

The photocatalytic degradation of 2-chlorophenol (2-CP) in aqueous solution was studied under visible light irradiation using mesoporous titania nanoparticles (MTN) catalyst. MTN was prepared by a microwave (MW) - assisted method under various MW power densities which are 0.56 (MTN1), 0.37 (MTN2) and 0.12 (MTN3) W g -1 . The catalysts were characterized by XRD, XPS, UV-Vis DRS and N2 adsorption-desorption. The characterization data show higher microwave power increased the crystallinity, number of oxygen vacancies (OV) and Ti 3+ surface defects (TSD) also surface area while decreasing the band gap of the MTN catalysts. MTN1 shows the highest degradation of 2-CP with 100% compared with MTN2 (88.48%) and MTN3 (86.39%). The optimum condition for photocatalytic degradation of 2-CP was obtained at pH 5, 10ppm of 2-CP and 0.075g of catalyst.

Activated carbon is known as one of the effective adsorbents in carbon dioxide adsorption, which is mainly attributed to its highly porous structure. Utilizing biowaste as the precursor for the activated carbon synthesis is considered as an attractive approach due to the biowaste being an inexpensive, renewable, abundant, and environmental-friendly material. This review article covers the various biowaste precursors used for activated carbon synthesis along with the comparison of its activating methods (which are physical and chemical activation). The relation between the activation methods and carbon dioxide adsorption performance is elucidated for better understanding. The functionalization of the biowaste-based activated carbon with basic nitrogen functionalizing agent as well as the challenges in the application of these adsorbents in carbon dioxide adsorption are also discussed.

Palm oil mill effluent (POME) has become critical issue among the oil palm industries due to its high organic contents and other contaminants which results in dark colour, turbid and bad smell. POME that is not treated effectively will result in significant wastewater issues as it disposes to the environment. Adsorption is a promising technique to purify the wastewater and has a wide variety of potential adsorbents. It works by adhering the pollutants on the high porous of activated carbon. Therefore, activated carbon has been widely used due to the effectiveness to adsorb pollutants and easy to produce. Previous studies proved that adsorption using activated carbon has been an effective method for the treatment of POME. This paper presents the utilization of activated carbon from agricultural biomass wastes for POME treatment. The materials are renewable, low-cost and viable as precursors of the activated carbon. The adsorption efficiencies and mechanisms of the activated carbon are discussed and summarized for easy reference. Development of methods for synthesis may become great challenges in the future, as well as the regeneration of activated carbon.

Nitrogen based nutrients are among the main components in aquaculture effluent to cause eutrophication condition, as it may cause algal bloom and depletion in oxygen once its concentration reaches the threshold. Nitrogen based nutrients are released into water in a form of nitrate after going through nitrification and denitrification. Cellulose based adsorbent are increasingly gaining attention due to its adsorption capability which comes in useful for recovery of nitrogen based nutrients. This study aims to evaluate the efficiency of powder cellulose as a potential natural cellulosic adsorbent for the recovery of nitrate ions in water under a constant pH 6.6. The uptake of nitrate by natural cellulosic adsorbent was investigated with variation of parameters such as initial concentration of 5.0 mg L−1 and 30.0 mg L−1, adsorbent dosage of 5.0 mg and 40.0 mg, temperature of 25.0 °C and 45.0 °C, and contact time of 10 minutes and 60 minutes. The experiment was conducted based on the experiment design by Design Expert Version 11 software in order to observe the recovery percentage of powder cellulose in different condition. The best recovery percentage was achieved at the condition of 5.0 mg L−1, 5.0 mg, 25.0 °C and 10 minutes with 96.50 % of recovery. This shows that the electrostatic force of attraction between powdered cellulose and nitrate anion nutrients have the potential to occur without heat and vacant pores around powdered cellulose was filled by nitrate anions in a limited amount of time. The model for the experiment which is most suited in this experiment is a natural log with a significant R2 value of 0.9982. This indicates that the adsorption of nitrate anion nutrients using natural cellulose adsorbent is indeed feasible. Therefore, there are potential of using cellulose extracted from biomasses in Malaysia, which will expand its product-value.

Dimethyl ether (DME) is a greener fuel, which is derived from low-rank coal. Integrating synthetic gas (syngas) as an intermediate and DME production is greener route for low-rank coal processing. Syngas could be fabricated by catalytic gasification over K2CO3 or Ca(OH)2 exhibited lower energy consumption than conventional gasification. Then, syngas product is transformed to DME via indirect or direct route. The indirect route depends on methanol production over metallic oxide, which prone to catalyst deactivation. In addition, acidity of the catalyst is also crucial for methanol dehydration to DME with high water tolerant. A hybrid catalyst is required for direct DME production, which challenging for coke deposition. In indirect route of coal to DME, the metallic oxide should be dispersed homogenously which could be achieved via hydrothermal assisted with ultrasonic or controlled sol-gel with surfactant. Meanwhile, direct route preferred introduction of dopant to increase oxygen vacancy or noble metal to reduce the pressure. The catalyst stability to water must be received more concern in the future since water could block the active site. There are still few studies emphasizing to the effect of CO2 as co-feed to syngas in DME synthesis. Besides that, the technoeconomic analysis and optimum condition for CO2 addition are crucial to be explored in upcoming years. Lastly, future research should be expanded to LPG fraction production directly from syngas. Multiple functional catalyst is required in this process to work synergistically in methanol production, two subsequent dehydration reaction to DME and olefins, then hydrogenation to alkane fractions.

It is believed of great interest to incorporate silver nanoparticles (Ag-NPs) into stable supported materials using biological methods to control the adverse properties of nanoscale particles. In this study, in-situ biofabrication of Ag-NPs using Entada spiralis (E. spiralis) aqueous extract in Ceiba pentandra (C. pentandra) fiber as supporting material was used in which, the E. spiralis extract acted as both reducing and stabilizing agents to incorporate Ag-NPs in the C. pentandra fiber. The properties of Ag-NPs incorporated in the C. pentandra fiber (C. pentandra/Ag-NPs) were characterized using UV-visible spectroscopy (UV-vis), X-ray Diffraction (XRD), Field Emission Transmission Electron Microscope (FETEM), Scanning Electron Microscope (Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Brunauer-Emmett-Teller (BET), Thermogravimetric (TGA) and Fourier Transform Infrared (FTIR) analyses. The average size of Ag-NPs measured using FETEM image was 4.74 nm spherical in shape. The C. pentandra/Ag-NPs was easily separated after application, and could control the release of Ag-NPs to the environment due to its strong attachment in C. pentandra fiber. The C. pentandra/Ag-NPs exposed good qualitative and quantitative antibacterial activities against Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922) and Proteus vulgaris (ATCC 33420). The dye catalytic properties of C. pentandra/Ag-NPs revealed the dye reduction time in which it was completed within 4 min for 20 mg/L rhodamine B and 20 min for 20 mg/L methylene blue dye, respectively. Based on the results, it is evident that C. pentandra/Ag-NPs are potentially promising to be applied in wound healing, textile, wastewater treatment, food packaging, labeling and biomedical fields.

The increase of carbon dioxide (CO2) emission due to anthropogenic activities has become a threat to our environment. Hence there is an urgent need to control its emission via carbon capture and storage (CCS) strategy. However, the readily available method, which is liquid amine absorption, possesses some drawbacks including being energy intensive and may cause material corrosion. Dry CO2 adsorption using amine-functionalized silica has been studied to provide a simple and cost-effective alternative for CO2 capture. Recently emerged dendritic fibrous silica possesses excellent morphology and characteristics to be developed as an effective CO2 adsorbent. Herein, the CO2 adsorption performance using amine-modified fibrous silica nanoparticle, KCC-1 was studied. As-synthesized KCC-1 was modified with tetraethylenepentamine (TEPA) via impregnation method. Its characteristics were studied before it was subjected to the CO2 adsorption experiment. The Fourier Transform Infra-red (FTIR) results indicates that TEPA was successfully impregnated with peaks at 3383 cm−1, 2935 cm−1, 2837 cm−1, 1558 cm−1, 1479 cm−1 and 1309 cm−1, while X-ray diffraction (XRD) analysis showed that KCC-1 structure was preserved. KCC-1/TEPA recorded higher adsorption capacity of CO2 compared to the unmodified KCC-1, with maximum adsorption capacity of 189.86 mg/g. Equilibrium isotherm model fitting of the CO2 adsorption was also carried out, and the adsorption data of KCC-1/TEPA fitted well to Toth isotherm. Overall, it has been demonstrated that KCC-1/TEPA has excellent potential to be used for CO2 adsorption, and more studies need to be conducted for its development.

High purity of Fe3O4 was prepared by electrochemical method in different concentration of sodium alginate (SA) as natural capping agent. The content of SA influenced the particle size and surface interaction to Fe3O4 as confirmed by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The highest photocatalytic activity was obtained for Fe3O4 synthesized with 0.05% SA with initial concentration of 15 mg/L Paracetamol. This result contributed to electrochemical advancement to produce Fe3O4 with simple method.

Benzene methylation is an important process for removing excess benzene in petrochemical industries to produce value-added products such as toluene and xylene. In this study, the performance of three types of zeolites, which is ZSM-5 (HZ), zeolite Y (HY) and zeolite β (Hβ) were investigated as catalyst in the benzene methylation reaction. The catalysts were characterized by N2 adsorption-desorption and FTIR. The N2 adsorption-desorption verified that the mesopores volume of the catalysts was in the following order: HB > HY > HZ. While, the FTIR-lutidine revealed that the HB possessed the highest amount of Brönsted acid sites followed by HZ and HY. The catalytic testing at 573 K showed that HZ gave good performance in benzene methylation with 55.2% and 22.1% yield of toluene and xylene, respectively. It is suggested that HZ catalyst with moderate amount of Brönsted acid sites and smallest mesopores volume appear to be effective for shape selective synthesis of toluene and xylene. In addition, pore structure of HZ also contributed to the high catalytic activity of benzene methylation.

In the recent years, traces of paracetamol in water body had increases due to the increasing usage and production of it. Since the discharge of wastewater containing paracetamol into water body can cause harm to environment and human health, it is crucial to find a suitable treatment method to overcome this problem. Advanced Oxidation Process (AOPs) with the assist of heterogeneous catalyst received growing interest as one of prospective treatment method. Some of noble catalysts such as platinum (Pt), gold (Au) and Silver (Ag) could serve as alternative to popular semiconductor catalyst. This study report a series of Ag (5, 10, 15 wt.%) loaded to Durio Zibethinus Husk (Ag/DZH) with detailed physicochemical properties using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). Then, the respective catalysts were tested for photodegradation of paracetamol (PCT) in aqueous solution. It was showed that the catalysts have a potential to degrade 5 mg/L of paracetamol solution (pH 9) with the highest degradation rate of 0.01197 mg/L.min using 0.03 g/L of 10 wt.% Ag/DZH catalyst. This result could serve as alternative for DZH utilization and reduce environmental pollution.

With our climate condition worsening day by day, the effort to mitigate this effect has been intensified. One of the ways to curb this issue is by reducing the release of carbon dioxide (CO2) to the atmosphere via CO2 capture. Among all the material used for CO2 capture, amine-impregnated porous silica was observed to be a promising adsorbent. Research has shown its potential, but the accessibility issues caused by its narrow pore opening limits its capabilities. KCC-1, the latest member of the porous silica family, possesses unique fibrous morphology that can solve this problem. In this paper, a series of Tetraethylenepentamine (TEPA)-impregnated KCC-1 (KCC-1/TEPA) synthesized at three different loading ratios (KCC-1 to TEPA 2:1, 1:1 and 1:2) is reported. Characteristics study was conducted to determine the effect of loading ratio on its properties, and its CO2 adsorption capacity was evaluated. FTIR peaks at 3430 cm−1, 3300 cm−1, 2950 cm−1, 2841 cm−1, 1658 cm−1, 1565 cm−1 and 1465 cm−1 revealed that the impregnation was successful, while XRD diffractogram indicated that KCC-1 structure remained preserved in all impregnated samples. Increased surface area and pore volume reduction was observed with the increase of TEPA-loading ratio. KCC-1/T1:2 reported the highest CO2 adsorption value among all three impregnated sample with 141 mg/g, while KCC-1/T2:1 recorded the lowest (82 mg/g). Results indicated that increasing TEPA loading ratio increases the number of active sites for CO2 to attached, hence lead to increase CO2 capture. Overall, it was shown that amount of CO2 adsorbed is related to the amount of TEPA loaded to the sorbent.

Porous membrane with enhanced proton conductivity is designed and prepared for vanadium redox flow battery (VRFB). The membrane is composed of ultra height molecular weight polyethylene (UHMWPE) grafted with poly(vinylbenzyl chloride) (PVBC) at different degrees of grafting (DOG). Subsequently, the membrane is functionalized with graphene oxide (UHMWPE-g-PVBGO) under ultrasonication. The functionalization of the GO on the porous substrates is confirmed by Fourier transform infrared (FTIR) and Raman analyses. UHMWPE-g-PVBGO membranes exhibited ∼37% higher proton conductivity compared to pristine UHMWPE upon modification at 30 °C and 100% relative humidity (RH). In relation to the degree of grafting, a higher degree of grafting possessed higher proton conductivity value for the porous membrane.

Graphene oxide (GO) was functionalized onto both sides of grafted porous polyethylene/polypropylene (PEPP) membrane sheet through sonication and simple immersion. Graphene oxide is a trending material in the field due to its excellent properties such as highly resistant to alkaline/acidic and strong mechanical strength, low cost and easily accessible. PEPP was successfully modified and the fiber gap of PEPP was reduced by grafting with GMA functionalized with GO. With addition of GO, modified PEPP membrane became hydrophilic with the addition of hydrogen bond from the GO. The FTIR results also showed traces of GMA on the surface of PEPP and after functionalized the membrane, it has shown prominent new peak which correspond to the C bond from GO from ultrasonication method.

Pollution is a long term environmental issue that is becoming a great concern faced by the world. The biggest source that leads to pollution is the increasing industrialisation due to the leakage of industrial waste into the environment, which can affect soil and ground water quality. Phenol is one of the hazardous wastes generated in which its level in water must be controlled. In this study, zinc oxide nanoparticles (ZN) were successfully synthesised by a facile microwave (MW)-assisted method under various power densities. It was found that a higher power density increased the crystallinity and surface area of the ZN but reduced the band gap energy of the catalyst. MW heating acted as a medium in the formation of oxygen vacancies (OV) where OV played an important role in the photocatalytic activity especially for an application under visible light irradiation. The particle size, surface area and different morphologies of the catalysts were also affected by the changes of power density and indirectly influenced the photoactivity. The ZN prepared with 0.12 (ZN1), 0.37 (ZN2) and 0.56 (ZN3) W g−1 power density were successfully degraded phenol with 64%, 70% and 87%, respectively under visible light irradiation. During the photocatalytic process, it was found that OV not only acted as an electron acceptor that inhibited the electron-hole recombination and eased the charge carrier migration but also narrowed the band gap energy. The ability of ZN3 in the degradation of other phenol derivatives such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-diCP) also showed a positive response whereby ZN3 was successfully degraded 58%, 50% and 63% of 2-CP, 4-CP and 2,4-diCP, respectively.

Biocomposite has been widely used as plastics replacement for its biodegradability. However, the water absorptivity defeats its purpose as food packaging. The water absorption analysis for pineapple peel fiber (PAPF) was done according to ASTM D570-98 and it has been proven that the water content increases to 7.2% with the 50% content of PAPF in the bio-composite (50% PAPF). For that matter, hydrophobic coating was synthesized and applied on PAPF based bio-composite. The bio-composite was produced using Low Density Polyethylene (LDPE), pineapple peel fibre (PAPF), Linear LDPE grafted maleic anhydride (LLDPE-g-MA) as compatibilizer and Refined, Bleached Deodorized Olein (RBDOL) as plasticizer. The coating was synthesized by using polydimethylsiloxane (PDMS) and decamethylcyclopentasiloxane as hydrophobic component, silica nano-particles as nanostructured particles and non-organic solvent and non-ionic surfactant p-octyl polyethylene glycol phenyl ether as surfactant. The emulsion was homogenized and after that sprayed onto the surface of PAPF bio-composite and dried in the oven at 50-60˚C for 24 hours. Through the 100µm magnification using field emission scanning electron microscope (FESEM), the hydrophobic coating was proven to conform the Cassie-Baxter hydrophobic property. C-O bond from the PAPF disintegrates after the production of bio-composite from the Attenuated Total Reflectance Fourier Transform Infrared (ATR FTIR) spectrometry transmittance. The application of the coating onto the surface of PAPF bio-composite gave the surface hydrophobic property where the contact angle changes from 82.27±2.66˚ which is hydrophilic to 122.63±2.17˚ which is hydrophobic. The bio-composite with the highest PAPF content will also exhibit self-cleaning ability which makes it suitable for the usage of hydrophobic food packaging material.

Waste tyre carbon adsorbent was prepared via three different calcination temperatures (500°C, 700°C and 900°C) and activated by sodium hydroxide solution. The phase and crystallinity analysis of each adsorbent is determined using X-ray diffraction analysis. The study revealed that different crystallinity of prepared adsorbent were obtained when calcination temperature is varied. Next, the effect of calcination temperature was investigated on the removal of paracetamol in aqueous solution. The highest percentage removal (99.37%) was obtained when the waste tire carbon adsorbent is calcined at 900°C for paracetamol initial concentration of 10 mg/L at pH 3 and 120 mins of contact time. In this case, the result obtained can be contributed to the production of adsorbent using waste tire with suitable calcination temperature for the paracetamol removal in aqueous solution.