Farook Adam

The immobilization of 3-(chloropropyl)triethoxysilane onto silica by a simple one-pot synthesis

Sodium silicate from rice husk ash (RHA) was transformed to functionalized silica with 3-(chloropropyl)triethoxysilane (CPTES) via a simple sol-gel technique in a one-pot synthesis. The (29)Si MAS NMR of the organo-silica complex (RHACCl) showed the presence of T(2), T(3), Q(3) and Q(4) silicon centers. The (13)C MAS NMR showed that RHACCl had three chemical shifts at 10.37, 26.70 and 47.69 ppm consistent with the three carbon atoms of the CPTES moiety. The presence of carbon, silicon and chlorine was determined by a combination of elemental analysis and EDX study.

Ceria and titania incorporated silica based catalyst prepared from rice husk: Adsorption and photocatalytic studies of methylene blue

Titania and ceria incorporated rice husk silica based catalyst was synthesized via sol-gel method using CTAB and glycerol as surface directing agents at room temperature and labeled as RHS-50Ti10Ce. The catalyst was used to study the adsorption and photodegradation of methylene blue (MB) under UV irradiation. The powder XRD pattern of RHS-50Ti10Ce was much broader (2θ=25-30°) than that of the parent RHS (2θ=22°). The catalyst exhibited type IV isotherm with H3 hysteresis loop, and the TEM images showed partially ordered pore arrangements. The TGA-DTG thermograms confirmed the complete removal of the templates after calcination at 500°C. RHS-50Ti10Ce exhibited excellent adsorption capability with more than 99% removal of MB from a 40 mg L(-1) solution in just 15 min. It also decolorized an 80 mg L(-1) MB solution under UV irradiation in 210 min, which was comparable with the commercialized pure anatase TiO2.

One-step synthesis of solid sulfonic acid catalyst and its application in the acetalization of glycerol: crystal structure of cis-5-hydroxy-2-phenyl-1,3-dioxane trimer

A one-pot method was employed to immobilize sulfonic acid onto silica obtained from rice husk ash using 3-(mercaptopropyl)trimethoxysilane to form a solid catalyst denoted as RHASO3H. BET measurements of the catalyst showed the surface area to be 340 m2 g−1 with the average pore volume of 0.24 mL g−1 and the pore diameter of 2.9 nm. Acidity test of cation exchange capacity and pyridine adsorption studies revealed the presence of Brønsted acid sites on the catalyst surface. The catalyst was used in the acetalization reaction of glycerol with benzaldehyde. Under optimized conditions, the reaction showed the maximum conversion of 78 % after 8 h with 67 % selectivity towards the five membered ring isomer. Variation in the glycerol concentration had a significant effect on the reactants conversion. A single crystal X-ray study of one of the products proved the existence of a unique trimer formed by hydrogen bonding by the six-membered cis-isomer. The catalyst was several times recycled without any loss of its catalytic activity.

Liquid Phase Oxidation of Acetophenone over Rice Husk Silica Vanadium Catalyst

Rice husk silica catalyst loaded with 10 wt% vanadium was synthesized from agricultural biomass via a sol-gel synthetic route at pH = 9. The catalyst was characterized by different physico-chemical methods. The FTIR spectra showed the formation of Si–O–V and V=O stretching bands. The presence of vanadium was confirmed by EDX elemental analysis. RH-10V possessed a high specific surface area of 276 m2/g and pore volume of 0.83 ml/g. The prepared catalyst possessed a narrow pore size distribution centered around 7.9 nm. The catalytic performance of RH-10V was tested in the oxidation of acetophenone at 70 °C. RH-10V was found to be an active catalyst in the oxidation of acetophenone, producing 36.28% conversion efficiency. The products identified were benzoic acid, 2-hydroxyacetophenone, phenol, acetic acid, and 3-hydroxyacetophenone.

The Synthesis and Characterization of Cobalt-Rice Husk Silica Nanoparticles

Spherical and needle-like cobalt nanoparticles incorporated on rice husk silica was synthesized by a simple, rapid and eco-friendly sol-gel route at room temperature. This was achieved by direct mixing of 20 wt.% Co 2+ with so- dium silicate from rice husk under ambient conditions to form RH-20Co. The cobalt was found to be isomorphously sub- stituted in the silica matrix. A good dispersion of cobalt nanoparticles was evidenced from X-ray diffraction. Transmis- sion electron microscopy confirmed the formation of well-dispersed and spherical cobalt nanoparticles with an average particle size of 5.6 nm. The magnetic properties of this material were measured with vibrating magnetometer. The satura- tion magnetization, Ms and coercive force, Hc was found to be 0.245 emu/g and 304.09 Oe respectively.

4-Methyl-N-[2-(pyridin-2-yl)ethyl-carbamo-thio-yl]benzamide.

In the title compound, C16H17N3OS, the dihedral angle between the planes of the benzene and pyridine rings is 71.33 (15)°. An intramolecular N—H⋯O hydrogen bond is present. In the crystal, weak aromatic C—H⋯O hydrogen bonds link the molecules into chains extending along a.

Ag-ZnO Incorporated Silica Based Bio-Nanocomposite Prepared by Low Cost Method for Photocatalytic Dye Degradation

Zinc-silver incorporated rice husk silica catalysts were prepared by a simple sol-gel precipitation. The FT-IR and thermal analyses are confirms the complete removal of the template after calcination at 773 K. From the XRD pattern, it could observed that zinc and silver which incorporated into rice husk silica with its characteristic crystalline form. Methylene blue (MB) was used to evaluate the photocatalytic activity of the prepared samples. During photodegradation, concentration of methylene blue was decreased within 1 h under the studied reaction condition. The incorporation of silver ions on rice husk silica improves the crystalinity and activity.

Crystal structure of (E)-4-meth-oxy-2-{[(5-methyl-pyridin-2-yl)imino]-meth-yl}phenol.

The molecule of the title Schiff base compound, C14H14N2O2, displays an E conformation with respect the imine C=N double bond. The molecule is approximately planar, with the dihedral angle formed by the planes of the pyridine and benzene rings being 5.72 (6)°. There is an intramolecular hydrogen bond involving the phenolic H and imine N atoms.

A Facile Template-Free Room Temperature Synthesis of Mesoporous Wormlike Nickel Phyllosilicate

Mesoporous wormlike nickel phyllosilicate was obtained from rice husk (agricultural biomass) by a simple, facile and template-free method which was carried out via sol-gel technique at room temperature. The synthesized nickel phyllosilicate had been characterized by various physico-chemical methods. Transmission electron micrographs revealed the formation of wormlike network of nickel phyllosilicate with uniform channel width. From the nitrogen sorption analysis, the nickel phyllosilicate shows a high specific BET surface area of 307 m 2 g -1 with a narrow pore size distribu- tion. The amorphous nature of silica and the presence of layered phyllosilicate-like structure were confirmed by x-ray diffraction pattern. The Fourier transform infrared spectrum show the presence of nickel in the silica matrix which was further confirmed by atomic adsorption analysis. The homogeneous dispersion of nickel in the silica matrix was confirmed by energy dispersion X-ray-mapping.

Benzoylation of p-Xylene at the Solid-Liquid Interface on Iron Incorporated Silica

A series of iron incorporated silica catalysts were prepared using rice husk ash as a source of silica. The specific surface areas of the catalysts were found to be in the range of 200-400 m 2 g -1 . The activities of the catalysts were tested for liquid phase Friedel-Crafts acylation reaction of p-xylene with benzoyl chloride. The catalyst RHA-10Fe exhibited the highest activity for benzoylation of p-xylene. The conversion of benzoyl chloride (BzCl) and the selectivity towards 2,5-dimethylbenzophenone (2,5-DMBP) were found to be 98.4 and 88.9 (%) respectively at 413 K.