Author
Sankaran Sugunan
Bio: Sankaran Sugunan is an academic researcher from Cochin University of Science and Technology. The author has contributed to research in topics: Catalysis & Adsorption. The author has an hindex of 28, co-authored 200 publications receiving 2812 citations.
Papers published on a yearly basis
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TL;DR: In this article, the intrinsic acidity among the ferrites was found to decrease in the order: cobalt>nickel>copper, whereas the strong acid sites were left unaffected.
Abstract: Ferrospinels of nickel, cobalt and copper and their sulphated analogues were prepared by the room temperature coprecipitation route to yield samples with high surface areas. The intrinsic acidity among the ferrites was found to decrease in the order: cobalt>nickel>copper. Sulphation caused an increase in the number of weak and medium strong acid sites, whereas the strong acid sites were left unaffected. Electron donor studies revealed that copper ferrite has both the highest proportion of strong sites and the lowest proportion of weak basic sites. All the ferrite samples proved to be good catalysts for the benzoylation of toluene with benzoyl chloride, copper and cobalt ferrites being much more active than nickel ferrite. The catalytic activity for benzoylation was not much influenced by sulphation, but it increased remarkably with calcination temperature of the catalyst. Surface Lewis acid sites, provided by the octahedral cations on the spinel surface, are suggested to be responsible for the catalytic activity for the benzoylation reaction.
216 citations
TL;DR: In this paper, the enzymes α-amylase, glucoamylases and invertase were applied to acid activated montmorillonite (K 10) via adsorption and grafting using glutaraldehyde as spacer.
119 citations
TL;DR: In this article, α-Amylase was immobilized on zirconia via adsorption, and the support and the immobilized enzymes were characterized using XRD, IR spectra and N2 adaption studies.
116 citations
TL;DR: In this article, α-amylase was applied to alumina via adsorption, and the results showed that the enzyme was getting adsorbed only on the external surface of the support, which may be due to interparticle diffusional mass transfer restrictions.
104 citations
TL;DR: In this paper, a novel method using titania sol via colloidal route as the pillaring agent was proposed, and the acidity of the catalysts was measured from temperature-programmed desorption of ammonia.
103 citations
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1,358 citations
TL;DR: In this paper, the authors summarized recent research dealing with development of titanium dioxide (TiO2) used for environmental applications and suggested new research directions, including preparation aspects for the development of this promising material.
Abstract: This paper summarizes recent research dealing with development of titanium dioxide (TiO2) used for environmental applications. TiO2 plays the most important role owing to its excellent chemical and physical properties. However, the TiO2 band edge lies in the UV region that makes them inactive under visible irradiation. In this regard, considerable efforts have been made to increase the visible light activity of TiO2 via the modification of its electronic and optical properties. Doping TiO2 using either anions or cations is one of the typical approaches that has been largely applied. Coupling TiO2 with a narrow bad gap semiconductor (MxOy/TiO2 or MxSy/TiO2) represents another approach. This work aims to encompass the new progress of TiO2 for an efficient application in water and wastewater treatment under visible light, emphasizes the future trends of TiO2 in the environment, and suggests new research directions, including preparation aspects for the development of this promising material.
1,281 citations
TL;DR: Nanoparticles have proportionally larger surface area than their microscale counterparts, which favors the filler-matrix interactions and the performance of the resulting material as mentioned in this paper, and they can have other functions when added to a polymer, such as antimicrobial activity, enzyme immobilization, biosensing, etc.
1,058 citations
TL;DR: In this paper, the authors present an overview of the relationship between organic chemistry and natural products, focusing on the Stereochemistry and the Chemistry of Natural Products (SCHP).
Abstract: Organic Chemistry By Dr. I. L. Finar. Vol. 2: Stereochemistry and the Chemistry of Natural Products. Pp. xi + 733. (London and New York: Longmans, Green and Co., Ltd., 1956.) 40s. net.
1,037 citations
TL;DR: The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches and can yield spinels with improved ORR/OER catalytic activities, which can further accelerate the speed, prolong the life, and narrow the polarization of fuel cells, metal-air batteries, and water splitting devices.
Abstract: Spinels with the formula of AB2O4 (where A and B are metal ions) and the properties of magnetism, optics, electricity, and catalysis have taken significant roles in applications of data storage, biotechnology, electronics, laser, sensor, conversion reaction, and energy storage/conversion, which largely depend on their precise structures and compositions. In this review, various spinels with controlled preparations and their applications in oxygen reduction/evolution reaction (ORR/OER) and beyond are summarized. First, the composition and structure of spinels are introduced. Then, recent advances in the preparation of spinels with solid-, solution-, and vapor-phase methods are summarized, and new methods are particularly highlighted. The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches. This regulation can yield spinels with improved ORR/OER catalytic activities, which can furth...
1,036 citations