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Mesoporous spinel Co3O4 nanosheets were synthesised via a simple sol-gel route using the Pluronic P123 triblock copolymer as the stabilising agent. Their structural, morphological, and textural properties were characterised. FTIR spectrum revealed the formation of cobalt oxide without any surface adsorbed impurities. Face centered cubic phase of spinel Co3O4 with the mean crystalline size of 26 nm was assigned by the X-ray diffraction analysis without the formation of other phases. Porous nanosheets and cave-like morphologies were identified from the scanning electron microscopy (SEM) images. Highly agglomerated more or less spherical particles with well separated lattice fringes, representing the oriented growth of nanocrystals, were noticed on the transmission electron microscopy photographs. Surface area analysis revealed that the spinel has high surface area of about 25 m2 g?1 with monomodal mesoporosity. The average pore size distribution was found to be about 15.8 nm. The as-prepared spinel photocatalyst showed a mild photocatalytic activity in the degradation of methylene blue (2.5 mg L?1) under UV light irradiation with air as the oxidising agent. Photocatalytic activity of the as-prepared reusable Co3O4 was found to be higher than that of the commercial spinel powder. 相似文献
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Silija Padikkaparambil Zahira Yaakob Binitha N. Narayanan Resmi Ramakrishnan Suraja Viswanathan 《Journal of Sol-Gel Science and Technology》2012,63(1):108-115
In the present study, a novel method for the silver nanoparticle incorporation into TiO2 sol is reported which provides efficient dispersion of inserted metal in the calcined gel. Glucose mediated metal nanoparticle synthesis eliminates the additional steps for the introduction of dopant over the support. Ag nanoparticle acts as competent trapping centers preventing the recombination of electron?Chole pairs. Thus, in spite of the low UV intensity present in the sunlight, considerable enhancement in the catalytic efficiency was observed for the degradation of dye pollutants over nanosilver loaded TiO2. Transmission electron microscopic images display the well isolated nanoparticles of silver having uniform dimensions of less than 5?nm over the best system, 2?wt% nanosilver loaded TiO2, which is accountable for its effectiveness as a photocatalyst. Anatase is found to be the photocatalytic active phase, as evident from the X-ray diffraction studies. 相似文献
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Lukman Hakim Zahira Yaakob Manal Ismail Wan Ramli Wan Daud Ratna Sari 《Chemical Papers》2013,67(7):703-712
Hydroxyapatite-supported Ni-Ce-Cu catalysts were synthesised and tested to study their potential for use in the steam reforming of glycerol to produce hydrogen. The catalysts were prepared by the deposition-precipitation method with variable nickel, cerium, and copper loadings. The performance of the catalysts was evaluated in terms of hydrogen yield at 600°C in a tubular fixed-bed microreactor. All catalysts were characterised by the BET surface area, XRD, TPR, TEM, and FE-SEM techniques. The reaction time was 240 min in a fixed-bed reactor at 600°C and atmospheric pressure with a water-to-glycerol feed molar ratio of 8: 1. It was found that the Ni-Ce-Cu (3 mass %-7.5 mass %-7.5 mass %) hydroxyapatite-supported catalyst afforded the highest hydrogen yield (57.5 %), with a glycerol conversion rate of 97.3 %. The results indicate that Ni/Ce/Cu/hydroxyapatite has great potential as a catalyst for hydrogen production by steam reforming of glycerol. 相似文献
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Y. G. Shee M. A. Mahdi M. H. Al-Mansoori A. Ismail N. A. M. A. Hambali A. K. Zamzuri R. Mohamad S. Yaakob 《Laser Physics》2009,19(12):2194-2196
A simple configuration for the reduction of stimulated Brillouin scattering threshold in photonic crystal fiber is presented.
The threshold reduction is contributed by the bidirectional pumping scheme through the reflection of transmitted Brillouin
pump back to the gain medium. The pump recycling scheme has greatly reduced the Brillouin threshold of a 200-m long of photonic
crystal fiber from 50 to 30 mW of Brillouin pump power. 相似文献
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Alibe Ibrahim Mustapha Matori Khamirul Amin Sidek Hj Ab Aziz Yaakob Yazid Rashid Umer Alibe Ali Mustapha Zaid Mohd Hafiz Mohd Nasir Salisu Nasir Maharaz Mohammed 《Journal of Thermal Analysis and Calorimetry》2019,136(6):2249-2268
Journal of Thermal Analysis and Calorimetry - Willemite is an inorganic semiconductor material used for optoelectronic applications. The present study purposes a new polymer thermal treatment... 相似文献
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N. N. Binitha P. V. Suraja Z. Yaakob M. R. Resmi P. P. Silija 《Journal of Sol-Gel Science and Technology》2010,53(2):466-469
In this work we describe and discuss the synthesis, and characterization of Co3O4 nanoflakes prepared by citric acid based sol–gel method using cobalt nitrate precursor. The average crystalline size of Co3O4 was estimated from the X-ray diffraction peaks of powders using Scherrer’s formula. The size of the particles deduced from
TEM agrees with XRD based values. The FTIR confirms formation of Co3O4. The SEM micrographs show the nanoflake morphology. Here we report the lowest temperature sol–gel method of preparation of
Co3O4 nanoflakes and its photocatalytic study for the degradation of dye pollutant methylorange. 相似文献
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Steam-reforming of ethanol for hydrogen production 总被引:1,自引:0,他引:1
Ahmed Bshish Zahira Yaakob Binitha Narayanan Resmi Ramakrishnan Ali Ebshish 《Chemical Papers》2011,65(3):251-266
Production of hydrogen by steam-reforming of ethanol has been performed using different catalytic systems. The present review
focuses on various catalyst systems used for this purpose. The activity of catalysts depends on several factors such as the
nature of the active metal catalyst and the catalyst support, the precursor used, the method adopted for catalyst preparation,
and the presence of promoters as well as reaction conditions like the water-to-ethanol molar ratio, temperature, and space
velocity. Among the active metals used to date for hydrogen production from ethanol, promoted-Ni is found to be a suitable
choice in terms of the activity of the resulting catalyst. Cu is the most commonly used promoter with nickel-based catalysts
to overcome the inactivity of nickel in the water-gas shift reaction. γ-Al2O3 support has been preferred by many researchers because of its ability to withstand reaction conditions. However, γ-Al2O3, being acidic, possesses the disadvantage of favouring ethanol dehydration to ethylene which is considered to be a source
of carbon deposit found on the catalyst. To overcome this difficulty and to obtain the long-term catalyst stability, basic
oxide supports such as CeO2, MgO, La2O3, etc. are mixed with alumina which neutralises the acidic sites. Most of the catalysts which can provide higher ethanol conversion
and hydrogen selectivity were prepared by a combination of impregnation method and sol-gel method. High temperature and high
water-to-ethanol molar ratio are two important factors in increasing the ethanol conversion and hydrogen selectivity, whereas
an increase in pressure can adversely affect hydrogen production. 相似文献
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Tentative identification of volatile flavor compounds in commercial Budu, a Malaysian fish sauce, using GC-MS 总被引:1,自引:0,他引:1
Budu is a famous Malaysian fish sauce, usually used as seasoning and condiment in cooking. Budu is produced by mixing fish and salt at certain ratio followed by fermentation for six months in closed tanks. In this study, four commercial brands of Budu were analyzed for their chemical properties (pH, salt content and volatile compounds). The pH of Budu samples ranged from 4.50-4.92, while the salt (NaCl) content ranged between 11.80% and 22.50% (w/v). For tentative identification of volatile flavor compounds in Budu, two GC columns have been used, DB-WAX and HP-5MS. A total of 44 volatile compounds have been detected and 16 were common for both columns. 3-Methyl-1-butanol, 2-methylbutanal, 3-methylbutanal, dimethyl disulfide, 3-(methylthio)-propanal, 3-methylbutanoic acid and benzaldehye have been identified as the aroma-active compounds in Budu due to their lower threshold values. 相似文献