Surface Engineered Metal Oxide and Carbon Nitride Heterostructures for Photo enhanced Electrochemical Ethanol Oxidation

Abstract

newline The development of sustainable, clean and renewable sources of energy is required to mitigate newlinethe issue of rising demand of energy and depletion of fossil fuels. Recently, a rapid interest has newlinebeen developed in the alcohol-based fuel cells as a promising alternative for clean power newlinegeneration. Among the various kind of alcohols, ethanol is considered as the best alternative newlineto be used in direct alcohol fuel cells due to its high energy density (~8 kWh kg -1 ), easy storage, newlinesafe transportation and environmental benign nature as it can be easily obtained from biomass. newlineAlong with its application in fuel cells, ethanol oxidation is widely used as a biomass oxidation newlineprocess to produce commodity chemicals. It can also be coupled with hydrogen evolution newlinereaction to replace sluggish oxygen evolution reaction in hybrid water electrolyzers to produce newlinehydrogen which is a clean source of energy. Noble metal-based catalysts such as Pt and Pd are newlinemost frequently used in direct ethanol fuel cells but their high cost, scarcity and poisoning of newlinethe catalytic surface due to the adsorption of CO limit their applications. Therefore, non- newlineprecious metal based cost-effective, durable and highly efficient electrocatalysts need to be newlinedeveloped. The photo-assisted electrocatalysis can further accelerate the kinetics of the newlinereaction and provide a more effective and renewable approach to convert solar and chemical newlineenergy to electrical energy. The work described in this thesis, utilizes heterogenous newlineelectrocatalysis process for the oxidation of ethanol molecules using metal oxide and carbon newlinenitride based heterostructures. The developed heterostructures have extended light absorption newlinein the visible region and thus can utilize solar energy for the photoelectrochemical process to newlineachieve better efficiency. In the first work, a type II heterostructure of NiTiO 3 -TiO 2 has been newlinesynthesized via hydrothermal approach followed by calcination. The prepared heterostructures newlinehave been used for the electrooxidation of ethanol and show