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Cherikkallinmel S.K.,Sree Neelakanta Government Sanskrit College Pattambi | Gopalakrishnan A.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Ramakrishnan R.M.,Sree Neelakanta Government Sanskrit College Pattambi | And 2 more authors.
RSC Advances | Year: 2015

Sodium aluminate is prepared from waste aluminium foils following an easy and low cost method. The crystalline NaAlO2 was found to have a uniform and highly porous morphology as revealed from the various characterization techniques. The developed catalyst showed high efficiency in the production of biodiesel from Jatropha oil. The reaction parameters were varied to find out suitable conditions for the transesterification reaction. The catalyst showed heterogeneity in methanol and is found to be reusable. This journal is © The Royal Society of Chemistry 2015.


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.


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.


Suraja P.V.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Binitha N.N.,Sree Neelakanta Government Sanskrit College Pattambi | Resmi M.R.,Sree Neelakanta Government Sanskrit College Pattambi | Silija P.P.,National University of Malaysia
Chemical Engineering Journal | Year: 2011

Thick-walled hexagonally ordered Cobalt and titanium loaded SBA-15 mesoporous photocatalysts were prepared by impregnating the metal precursor solution on the hydrothermally stable support. The catalysts were analyzed using various spectroscopic and diffraction techniques. XRD measurements revealed that Co exists as its spinel structure Co3O4 and Ti is present in the anatase TiO2 phase. FTIR showed the absorption bands of Co3O4 around 667 and 565cm-1. The visible light absorbance of the photocatalytic systems was studied by Diffuse Reflectance Ultraviolet-Visible spectroscopy (UV-vis DRS) measurements. Systems exhibited fairly good performance as photocatalysts for pollutant degradation under visible light. SBA-15 support was helpful in the easy separation of catalysts after the completion of the degradation. In the case of cobalt loaded SBA-15, activity is found to be maximum when the cobalt loading is 40% whereas 50% Ti loaded SBA-15 is found to be the most active among the prepared systems for the degradation of the dye pollutant methylene blue (MB). © 2011 Elsevier B.V.


Yaakob Z.,National University of Malaysia | Narayanan B.N.,Sree Neelakanta Government Sanskrit College Pattambi | Padikkaparambil S.,National University of Malaysia | Padikkaparambil S.,Sree Neelakanta Government Sanskrit College Pattambi | And 3 more authors.
Renewable and Sustainable Energy Reviews | Year: 2014

Biodiesel consists of fatty acid monoalkyl esters and is derived from feedstocks, such as vegetable oils, used cooking oils and animal fats. Biodiesel is considered to be a promising alternative biofuel. Recently, biodiesel has received additional attention and intense research has been performed in this field all over the world due to its lower environmental impact compared to the conventional diesel fuels. The central drawback of biodiesel is its susceptible nature to oxidation due to the presence of unsaturated fatty acid portion in the ester. Oxidative degradation occurs in biodiesel on aerobic contact during storage as well as with metal contaminants. Antioxidants are very effective for the eradication of those oxidation stability problems. This article presents an overview of the factors affecting the oxidation stability of biodiesel and the methods available for the prediction of oxidation stability. The effect of antioxidants in preventing the oxidation of biodiesel is also discussed. © 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.


Padikkaparambil S.,National University of Malaysia | Yaakob Z.,National University of Malaysia | Narayanan B.N.,Sree Neelakanta Government Sanskrit College Pattambi | Ramakrishnan R.,Sree Neelakanta Government Sanskrit College Pattambi | Viswanathan S.,National University of Malaysia
Journal of Sol-Gel Science and Technology | Year: 2012

In the present study, a novel method for the silver nanoparticle incorporation into TiO 2 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-hole 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 TiO 2. 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 TiO 2, 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. © 2012 Springer Science+Business Media, LLC.


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 | And 2 more authors.
Nanotechnology 2010: Advanced Materials, CNTs, Particles, Films and Composites - Technical Proceedings of the 2010 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2010 | Year: 2010

This work reports on the synergistic effect of cobalt on Carbon and Nitrogen codoped anatase titania photocatalysts prepared via sol-gel method using urea as the nitrogen source. Visible light activity is achieved as result of anion doping and further improvement is manifested in the photocatalytic activity with the cobalt doping. The photocatalysts prepared are characterized using various analytical techniques. Diffuse reflectance spectral (DRS) analysis shows visible light absorption. Efficient dispersion of cobalt and anatase phase stability is clear from X-ray diffraction (XRD) patterns. Photodegradability under visible light is investigated using methylene blue which is a widely used dye in photodegredation studies. Titania upon C & N codoping shows good activity in very dilute solutions whereas with cobalt doping, the activity is retained even at higher dye concentrations. Reaction parameters are optimized to improve the photodegradation capacity of the prepared systems. Present systems show excellent activity even within 15 minutes and are found to be reusable as well.


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.


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.

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