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The study of TiO2-sulfonated carbon-derived from Eichhornia crassipes (TiO2/SCEC), as an effective adsorbent to remove Methylene blue (MB) and Congo red (CR) dyes from aqueous solution, has been conducted. The preparation steps of TiO2/SCEC adsorbent involved the carbonisation of E. crassipes powder at 600 °C for 1 h, followed by sulfonation of carbon for 3 h and impregnation through titanium(IV) isopropoxide (500 µmol). The physical properties of the adsorbents were characterized by using X-ray fluorescence (XRF), Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with Energy dispersive X-ray (SEM-EDX), Thermogravimetric analysis (TGA) and nitrogen adsorption-desorption studies. The dye removal study using TiO2/SCEC adsorbent was carried out by varying of contact time, adsorbent dosage, initial dye concentration, pH, particles size of adsorbent and temperature. The kinetics models were determined by the effects of contact time and the thermodynamic parameters (ΔH, ΔS, and ΔG), which were calculated by the effects of temperature. The results showed that the maximum dye removal capacity of TiO2/SCEC were 18.8 mg.g-1 for MB and 36.5 mg.g-1 for CR. The removal of MB and CR dyes using TiO2/SCEC adsorbent performed a pseudo-second order kinetic models with spontaneity. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The flourishing of palm oil industry in Malaysia is always shadowed by the massive palm oil mill effluent (POME) produced along the oil-extraction process. Without a proper treatment, this POME generated might impose a disastrous destruction to the environment by contaminating water resources. Currently, the open ponding system is widely employed to degrade POME in Malaysia. However, this remediation can hardly cope with hurdle set by the Department of Environmental nowadays due to the growing of the environmental awareness. Therefore, there are strong urges demanding for a new alternative that can effectively treat the POME waste, or even better converting it into renewable energy resources along the treating process. This review provides insights into the feasibility of photocatalytic process for co-treatment of POME for the renewable energy production. Besides, the efficiency and versatility of proposed photocatalysts, TiO2 and ZnO, were also outlined in the current review. This review would serve as an important remark for future studies for not only POME treatment, but also the organic wastewater treatment from the industrials.

Mesoporous titania has been successfully synthesized by photodegradation removal of cetyltrimethylammonium bromide as the surfactant, after slow hydrolyzation of titanium(IV) isopropoxide. Fourier transform infrared spectra proved that photodegradation has successfully decreased the peak areas of the alkyl groups from the template. The nitrogen adsorption analysis showed that the pore size and the specific surface area of the mesoporous titania were 3.7 nm and 203 m 2 g −1 , respectively, proving the mesoporosity of the titania obtained with the existence of the interparticle mesoporosity which was confirmed by transmission electron microscopy. Based on X-ray diffraction results, the mesoporous titania obtained was in the form of crystalline anatase phase. Furthermore, results from the diffuse reflectance ultra violet-visible spectra showed that the composition of tetrahedral titanium(IV) was more than the octahedral titanium(IV). When the mesoporous titania obtained was used as a catalyst in the oxidation of styrene, an improvement in the conversion of styrene (38%) was observed when compared to those obtained using Degussa P25 TiO 2 (14%) as the catalyst.

Improving the antimicrobial activity and radical scavenging ability of a textile-based nanocomposite (textile/TiO2, textile/Al2O3/TiO2, textile/Al2O3 and textile/Al2O3–TiO2 bimetal oxide nanocomposite) is the key issue in developing a good and flexible wound dressing. In this work, flexible textile attached with Al2O3–TiO2 nanoparticles was prepared by dipping the textile in a suspension containing Al2O3–TiO2 nanoparticles (150 mmol l−1). The mean radical scavenging ability for textile/TiO2, textile/Al2O3/TiO2, textile/Al2O3 and textile/Al2O3–TiO2 bimetal oxide nanocomposites as measured by liquid ultraviolet visible spectroscopy (UV-Vis) coupled with dependence formula was 0.2%, 35.5%, 35.0% and 38.2%, respectively. Based on the X-ray diffraction (XRD) patterns, the preface reactive oxygen species (ROS) scavenging ability shown by the textile/Al2O3–TiO2 bimetal oxide nanocomposite is most probably caused by the crystal structure concluding in a corundum-like structure, with Al3+ ions filling the octahedral sites in the lattice. Increased antimicrobial activity measured by optical density at 600 nm recorded for textile/Al2O3–TiO2 bimetal oxide nanocomposites showed better interaction between Al2O3 and TiO2 nanoparticles. This good interaction is expected to lead to better antimicrobial and radical scavenging ability as shown by the E. coli and human skin fibroblast (HSF) cytotoxicity tests, respectively.

This research work describes the effect of hydrophobicity in inducing the diffusion of alkene substrates to the catalytic active sites. The aim of this research is to improve the catalytic activity by tailoring the degree of hydrophobicity of the catalyst. Silica functionalized with solid non-silylated Ti-salicylaldimine complex was prepared at room temperature by mixing imine ligand and Ti(IV) sulphate solution. The amorphous, solid complex formed was further silylated with octadecyltrimethoxysilane (OTMS) to induce hydrophobicity. The composition of the resulting silica functionalized with silylated Ti-salicylaldimine complex was varied with Ti:OTMS molar ratio in the range of 1:1/4 to 1:4 at room temperature. The successful attachment of alkylsilyl groups to silica functionalized with Ti-salicylaldimine complex was proven by the FTIR and 29Si solid state NMR spectra. The FTIR spectra showed increasing peak area for sp 3 C-H stretching mode (ca. 2919 cm−1 and 2850 cm−1) and decreasing peak area for Si-OH band with increasing amount of OTMS. TGA showed less water content with higher amount of alkylsilyl groups in the catalyst. This is in agreement with the lower kinetic rate of water adsorption capacity for the hydrophobic catalysts prepared. It was observed that the hydrophobic, silica functionalized with silylated Ti-salicylaldimine complex exhibited higher substrate conversion and reusability compared to the non-silylated catalyst.

Titania-loaded coal char catalyst was successfully prepared. The preparation steps involved pyrolysis of low rank coal at different temperatures and durations, sulfonation, impregnation of titanium(IV) isopropoxide, and then heating at 110 °C. It is found that the coal chars’ surfaces were rough after sulfonation and impregnation, while large pore volume, high surface area and carbon composition were observed at low pyrolysis temperature for short duration. These properties contributed to high selectivity towards benzaldehyde (> 90 %) at 600 °C (0.5–2 h)) in styrene oxidation using aqueous hydrogen peroxide as the oxidant.

a b s t r a c t Temperature-controlled selectivity in oxidation of 1-octene by using aqueous hydrogen peroxide in phase-boundary catalytic system was demonstrated by using alkylsilylated-Ti(IV) salicylaldimine com- plex at a series of temperature (25-90 ◦ C). The catalyst was synthesized by titanium(IV) sulfate solution, salicylaldehyde, and 3-aminopropyltrimethoxysilane as the precursors and followed by the attachment of octadecyltrimethoxysilane. It was found that the reaction system resulted in high selectivity at low temperature. One suggests that the high selectivity in the oxidation of 1-octene by aqueous hydrogen peroxide was related to partitioning of alkylsilylated-titanium(IV) salicylaldimine complex in immiscible liquid-liquid phase boundary which is temperature dependent.

ZSM-5 has been successfully synthesized by hydrothermal method using Indonesian Bangka kaolin as the aluminium source without an organic template and preactivation by calcination utilizing silicalite and ZSM-5 seedings. There are three parameters that made kaolin a very suitable aluminium source in the synthesis of ZSM-5 by using this method. The first parameter was the presence of types of seeds (silicalite and ZSM-5). Secondly, the molar ratio of Si/Al was in the range of 40–60. Thirdly, the concentrations of NaOH were varied from 6 to 12 mol with 1800 mol water. Interestingly, the use of silicalite seed produced pure ZSM-5 zeolite, whereas analcime and mordenite appeared as side products when ZSM-5 was used as the seed. The above effects can be illustrated by the following mechanism. Kaolin was fully dissolved in the basic mixture solution containing concentrated NaOH and silica sols, and followed by the crystallization in the presence of seeds (silicalite and ZSM-5). The mechanism was postulated on the basis of XRF, XRD, 29Si and 27Al MAS NMR analyses.

Lewis and Brönsted acidity were studied on ZSM-5 with combination of pyridine adsorption and FTIR vibration, ZSM-5 synthesized using kaolin Bangka Indonesia with an increase in the molar ratio of Si/Al 30-60 without pre-treatment and without organic templates and with seeds silicalite. Interestingly, the intensity of the infrared showed an increase of band vibration pyridine as absorbed Brönsted and Lewis acid sites in a molar ratio increase of Si/Al in ZSM-5, indicating an increase in the number of silanol (Brönsted acid) and deformed silica (Lewis acid) because the amount of Aluminum in ZSM-5 decrease with increase Si/Al but amount acidity increase. 29Si and 27Al MAS NMR analysis was supported by the results of infrared to indicate that all of the aluminum atom is coordinated with their neighbors are the same in ordering the ZSM-5 framework and 27Al MAS NMR showed a sharp peak of all the variations of Si/Al except the Si/Al 30 shows a low peak area. XRD analysis supported that the ZSM-5 structure formed is pure and crystal and a decrease in crystallinity proven for more than Si/Al 50, that defects silica occurs in ZSM-5, this corresponds to the growing number of Lewis acid sites caused by defects silica described the infrared results.

Titanium-amine functionalized silica was successfully prepared by a so-called one-pot approach by using 3-aminopropyltrimethoxysilane (APTMS), tetraethoxysilane (TEOS) and titanium(IV) sulfate as precursors. It is demonstrated that the TEOS/APTMS molar ratio in the synthesis of titanium-amine functionalized silica affected the local coordination of titanium and its corresponding positive impact on catalytic activity in oxidation of limonene by aqueous hydrogen peroxide.

article i nfo The role of Lewis and Bronsted acidities in alkylation of resorcinol is demonstrated through the gallium- zeolite beta by varying the amount of Lewis and Bronsted acid sites. The synergism of Lewis and Bronsted acid sites takes place heterogeneously in Friedel-Crafts alkylation of resorcinol with methyl tert-butyl ether to produce 4-tert-butyl resorcinol and 4,6-di-tert-butyl resorcinol as the major and minor products, respectively. © 2011 Elsevier B.V. All rights reserved.

Titania (TiO 2 ) has been an important renewable material that is able to convert solar energy into chemical energy in recent years. Therefore, the main focus of this paper centers around different strategies and precursors to prepare TiO 2 with various shapes, e.g. perforated hollow TiO 2 , anatase hollow TiO 2 spheres, well-aligned TiO 2 and rambutan-like TiO 2 /liquid crystal composite, so as to utilize these materials in an environmental-benign way.

Micro structured silica containing cobalt oxide materials was prepared by the calcination of silica containing cobalt salicylaldimine complexes. The SEM image showed that the prepared materials from higher content of cobalt salicylaldimine complexes had sponge-like structured. The IR and DR UV-Vis, spectra confirmed the presence of different species of cobalt oxide in materials originated from higher contain of the complex, which is attributed as Co3O4. The Co3O4 was believed as active species in catalytic hydrolysis of sodium borohydride. The catalytic testing also showed that the material originated from higher content of complex generated much higher hydrogen gas compare to the lower ones.

In this study, a hierarchically porous carbon was prepared from a natural material, Averrhoa bilimbi, also known as bilimbi. The bilimbis were cut into preferred shape and size before drying by freeze drying method. The bilimbis were then subjected to pyrolysis at temperature of 400°C and transformed to porous carbon. Scanning electron microscopy (SEM) revealed that the bilimbis have a hierarchically porous structure in the macro-range. The diameter of the porosity decreased inwards from 30 to 8μm. Different types of motor oil, which were used to represent bulky molecules, were employed to test the diffusivity of these molecules from the bilimbi. It was found that the oils were able to diffuse through the hierarchically porous bilimbi in 2 to 3 hours, depending on the viscosity of the oils. Therefore, it can be concluded that, Averrhoa bilimbi possesses hierarchical porous structure with interconnected pores and capability to diffuse bulky molecules.

Titanium dioxide supported sulfonated low rank coal catalyst possesses high catalytic activity in liquid phase oxidation of styrene with aqueous hydrogen peroxide at room temperature. The catalysts were prepared by sulfonation with concentrated sulfuric acid and impregnation of titanium dioxide (500-2500 µmol). The effect of titanium dioxide impregnation and calcinations on the catalysts were studied by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, BET surface area, field emission scanning electron microscopy and hydrophobicity measurement. The catalytic activity of the catalysts in the oxidation of styrene by aqueous H2O2 without calcination increased when the amount of titanium dioxide increased. Meanwhile, the catalytic activity of the catalyst calcined at 500oC for 2 h was lower than before calcination. It is suggested that the agglomeration of titanium dioxide and hydrophobicity play important role in the catalytic activity of titanium dioxide-supported sulfonated low rank coal in the oxidation of styrene with aqueous H2O2.

Cobalt Schiff base complex is widely used in many reactions such as reduction process, carbonylation of alcohol and oxidation of alkenes. Generally, this catalyst is in the powder form. It is difficult to separate the catalyst from the reaction mixture due to the small particles size of the catalyst. One way to easily separate the catalyst is by applying external magnetic field. However these catalysts would have to possess magnetic properties for this method to work on. One of the strategies to solve this problem is by adding magnetic material into the catalysts. Magnetite is a common magnetic material used as a support material which can be synthesized by the co-precipitation method of Fe2+ andFe3+. Normally, magnetite is covered by silica in order to stabilize and reduce its toxicity. This can be done by using the sol-gel approach. Silica coated magnetite is widely used as a support material because of its high surface area and easy catalyst separation after the reaction simply by applying an external magnetic field. In this research, cobalt Schiff base complex/silica@magnetite was synthesized from the condensation of cobalt (II) salicylaldehyde with 3-aminopropyltrimethoxy silane on the surface of silica@magnetite. The catalysts were characterized using Fourier transform infrared spectrometer, scanning electron microscopy and diffuse reflectance ultra-violet visible spectrometry.

The drug-delivery field has been an attractive as well as challenging area for research. With the emerging of new formulated drugs and pharmaceutical compounds, development of good drug-delivery system (DDS) is crucially required. This study aims to utilize albumin as the drug template in silica/albumin/drug (S/A/D) system. Prior to designing this system, the interaction between silica and albumin was investigated. It is hypothesized that high interaction between silica and albumin may result in slower drug release over time, which is preferred for a good DDS. Silica and albumin (S/A) materials were prepared by using fumed silica and tetraethyl orthosilicate (TEOS) as the silica precursors. Three different S/A samples were prepared; fumed silica with albumin (FS/A), fumed silica with pre-treated albumin by sodium borohydrate (FS/A-N), and silica sol (TEOS) with albumin (SS/A). In-vitro release of albumin in phosphate buffer solution (pH 7) was carried out to examine the interaction between albumin and silica. The concentration of albumin was detected at 280 nm by UV-visible spectrophotometer. All samples were characterized by diffuse reflectance-UV-visible spectrophotometer (DR-UV), Fourier transform infrared spectrophotometer (FTIR) dan thermogravimetric-differential thermal analysis (TG-DTA). DR-UV results show that SS/A exhibited the lowest absorption intensity at 280 nm, which indicates better interaction between silica and albumin. This result was supported by the presence of Si-O stretching band of silanol at 952 cm-1 from the FTIR spectrum. Release study of albumin demonstrated that the release of albumin from SS/A was slowest compared to those of FS/A and FS/A-N.

The design and synthesis of particulate materials for new catalyst systems with novel properties remain a big challenge today. Here an attempt has been made to synthesize particulate materials for several heterogeneous catalytic systems, which contain examples from our recent research projects in this area. The particulate catalysts have been designed for single centre catalyst, phase-boundary catalyst, bifunctional catalyst, photocatalyst and chiral catalyst. In our current research, the synthesis of well-aligned titanium dioxide catalyst with very high length to the diameter ratio has also been demonstrated for the first time by sol-gel method under magnetic field with surfactant as the structure aligning agent.