Faculty Publications
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Item Morphological and structural characterisation of sol-gel electrospun Co3O4 nanofibres and their electro-catalytic behaviour(Royal Society of Chemistry, 2015) George, G.; Elias, L.; Hegde, A.C.; Anandhan, S.Evolution of hydrogen and oxygen are a crucial part of many renewable energy systems. The replacement of the essential and expensive components in such systems can reduce the capital cost and improve the effectiveness of those systems. In this study, Co3O4 nanofibres were fabricated from sol-gel assisted electrospun poly(styrene-co-acrylonitrile)/cobalt acetate tetrahydrate precursor composite fibres. The morphological and compositional features of the Co3O4 nanofibres obtained after calcination of the precursor nanofibers were studied using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results of X-ray diffraction study and Raman spectroscopy revealed that the average grain size of the fibres increased with the calcination temperature. Clear evidence of defects in the fibres was observed in ultraviolet-visible-near infrared and energy dispersive spectroscopic measurements. The electrocatalytic behaviour of Co3O4 nanofibres obtained at different calcination temperatures was studied using them for the water splitting reaction in an alkaline medium. The maximum efficiency in the hydrogen evolution reaction was achieved using the Co3O4 nanofibres obtained at the lowest calcination temperature, which had the highest surface area and the smallest grain size. © The Royal Society of Chemistry 2015.Item Sol-gel electrospun ZnMn2O4 nanofibers as bifunctional electrocatalysts for hydrogen and oxygen evolution reactions(Institute of Physics Publishing helen.craven@iop.org, 2019) Shamitha, C.; Shetty, A.R.; Hegde, A.C.; Anandhan, S.Electrochemical water-splitting has gained significant attention for the development of next generation fuels. The present work is an investigation on the electrocatalytic activity towards both Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER) of ZnMn2O4 (ZMO) nanofabrics synthesized by sol-gel electrospinning followed by calcination (at 500, 600 and 700 °C). Poly(styrene-co-acrylonitrile) was used as the polymeric binder for the production of nanofabrics. The morphological features of ZMO nanofabrics were studied by scanning electron microscopy and field emission scanning electron microscopy. The electrocatalytic behavior of ZMO nanofabrics obtained at different calcination temperatures was evaluated using chrono-potentiometry, cyclic voltammetry, and linear sweep voltammetry in an alkaline medium (1 M KOH). The ZMO nanofabrics calcined at 500 °C exhibited the maximum electrocatalytic activity towards HER. This can be ascribed to their superior specific surface area (79.5 m2 g-1). The nanofabrics calcined at 700 °C displayed the least potential for O2 evolution and hence they are considered to be effective for OER. The results prove that ZMO nanofabrics are promising candidates as bifunctional electrocatalysts for water-splitting applications. © 2019 IOP Publishing Ltd.