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Suraja P.V.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Binitha N.N.,Sree Neelakanta Government Sanskrit College Pattambi | Triwahyono S.,Ibnu Sina Institute for Fundamental Science Studies | Silija P.P.,National University of Malaysia
Clean Technologies and Environmental Policy | Year: 2013

Nanosized cobalt oxide particles are incorporated into SBA 15 mesoporous silica materials and are effectively used for the first time as adsorbent materials for aquatic dye pollutant removal. Cobalt is found to exist in its Co3O4 spinel structure as evident from FTIR and X-ray diffraction studies. The best weight ratio of metal loading to show excellent adsorption of methyleneblue is found to be 10 wt% Co over the support. There, Co3O4 spinel nanoparticles lie inside the pores of mesoporous silica. Further increase in the percentage of metal loading decreases the adsorption capacity which may be due to the agglomeration of nanoparticles over the silica support as evident from TEM photographs. Cobalt-doped systems of the present study, having good adsorption capacity of methyleneblue, are prepared via impregnation of cobalt nitrate over SBA 15 in aqueous medium. Here, we introduce a new SBA 15-based system for the fast removal of aquatic dye pollutants which is highly economical for industrial applications. © 2012 Springer-Verlag.

Kandaramath Hari T.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Binitha N.N.,Sree Neelakanta Government Sanskrit College Pattambi
Renewable and Sustainable Energy Reviews | Year: 2015

Air transport describes an inevitable part in the day to day life of the modern world. It is highly responsible for the worldwide social contacts and business developments. The use of petroleum fuels as energy source for air transport is not sustainable. Aviation is one of the leading contributors to the total greenhouse gas emissions. Also, the fossil fuel prices are becoming more volatile day by day. So it is very essential to introduce and industrialize alternative aviation fuels generated from renewable resources, especially biomass. A number of industrial commitments and collaborations have emerged to find alternative ways to reach bio aviation fuels. Research on the conversion of biomass based sources to bio jet fuels is of current interest. The main concern is the production of biojet fuel, from renewable resources, with relatively low greenhouse gas life cycle and sustainability with affordable price. The present paper overviews the opportunities and challenges in the development of alternative fuels for aviation. The production process, feedstock used and the most promising global projects are also reviewed. © 2014 Elsevier Ltd. All rights reserved.

Suraja P.V.,National University of Malaysia | Binitha N.N.,National University of Malaysia | Binitha N.N.,Sree Neelakanta Government Sanskrit College Pattambi | Yaakob Z.,National University of Malaysia | Silija P.P.,National University of Malaysia
IOP Conference Series: Materials Science and Engineering | Year: 2011

The use of montmorillonite clays as a matrix, or as a host, for obtaining intercalated/supported metal particles has potential applications in catalysis and other areas. The gold nanoparticles were obtained from the most common anionic gold precursor HAuCl43H2O by deposition-precipitation (DP) methods. However, it is difficult to prepare nanoscale gold catalysts supported on silica surfaces with lower isoelectric point (IEP). Homogeneous precipitation method using urea also fails on silica surfaces. Reasons for the inefficiency of these methods are the negative charge of the metal precursor as well as the support surface and the high pH required for depositing gold nanoparticles. In the present work, we use glucose as the reductant in the presence of stabilizer for preparation of nano gold supported on montmorillonite clay. There is no need of increasing the pH of the solution to reduce the Au3+ ions. The prepared systems are characterized using various techniques such as using X-ray fluorescence (XRF), UV-VIS Diffuse reflectance spectra (DRS) and Fourier Transform infra red spectra (FTIR) to prove the efficiency of the present method.

Viswanathan S.,National University of Malaysia | Narayanan B.,Sree Neelakanta Government Sanskrit College Pattambi | Yaakob Z.,National University of Malaysia | Periyat P.,University of Calicut | Padikkaparambil S.,National University of Malaysia
Journal of Porous Materials | Year: 2014

Nanogold was dispersed over cobalt-loaded SBA 15 to create an effective redox catalyst. The support was identified as spinel Co3O4 attached to mesoporous SBA 15 based on XRD, FTIR and TEM analyses. The gold crystallites were found to be in the nanosize range (8-15 nm) by the application of the Scherrer equation to the XRD data. XPS analysis provided insight into the state of the gold nanoparticles. The selective hydrogenation of nitrobenzene over nanogold doped cobalt-loaded SBA 15 catalysts was investigated in a fixed bed down flow reactor. The selectivity for the desired product, aniline, was very high with a maximum conversion of 98.9 % of nitrobenzene. The high catalytic performance is attributed to the efficient dispersion of gold nanoparticles over the support. Performing the reaction in the flow reactor maximizes the access of the reactants to the catalysts without the aid of any solvent, which further eliminates the filtration steps required to remove the catalyst after the reaction. Conducting the reaction at 200 °C facilitates the recovery of the product (aniline), from the catalyst, as soon as it is formed. © 2013 Springer Science+Business Media New York.

Silija P.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Yarmo M.A.,National University of Malaysia | Sugunan S.,CUSAT | Binitha N.N.,Sree Neelakanta Government Sanskrit College Pattambi
Journal of Sol-Gel Science and Technology | Year: 2011

The photocatalytic activity of carbon and nitrogen co-doped sol gel TiO2 is tested using methyleneblue degradation and it is found that the activity drops sharply with increase in calcination temperature. The system calcined at 300 °C was found to be the most efficient in dye degradation and can be considered as a good candidate for the future photocatalytic applications. This highly active anion doped TiO2 is found to show amorphous nature. Elemental analysis reveals the co existence of C and N dopants, which may be responsible for the high efficiency of the catalyst. Visible absorbance is evident from the UV-VIS Diffuse Reflectance Spectra. The N2 adsorption desorption studies show the H1 hysteresis loops and a well defined mesoporous nature is observed for the catalytic systems prepared in the presence of urea. XPS analysis indicates the presence of Ti-C and Ti-N bonds which are responsible for the visible light activity of the photocatalysts. © 2011 Springer Science+Business Media, LLC.

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