Interface Engineering in Nano Zinc Oxide Rendering Visible Light Photocatalysis and Photoelectrochemical Hydrogen Generation Insights into Effective Charge Separation by Carbon Doping and Graphene Hybridization

Abstract

With rapid industrialization and fast growing population, the newlineworld is confronted with energy shortage and environmental pollution. newlineThe need to develop economically feasible strategies to address these very newlinealarming problems remains extremely important. Recent advancements in newlinenanomaterials provide insights into the development of facile environmental newlinefriendly methodologies to tackle the profound issues efficiently. The newlineeffective utilization of solar energy for sustainable development has always newlinebeen a world-wide research focus. Photocatalytic pollutant degradation newlineand photoelectrocatalytic hydrogen evolution are emerging as advanced newlinetechnology involves direct conversion of solar energy to chemical energy. newlineThe applicative potential of the metal oxide semiconductors has gained newlinetremendous attention in this direction due to biocompatibility, novel newlineproperties, inexpensive and sustainable nature. Several promising metal newlineoxide semiconductors such as TiO2, ZnO, Fe2O3, SnO2 etc. have been newlineactively used for visible light driven photocatalysis. newlineAmongst these semiconductor photocatalyst, ZnO has emerged as newlineleading candidate in green environmental organization system owing to newlinebiocompatibility, non-toxicity, strong oxidation ability, direct and wide newlineband gap, large free-exciton binding energy and diversity in size and newlineshape. Although ZnO has wide band gap, it absorbs large amount of newlineUltra-Violet light compared to TiO2 and exhibits higher photocatalytic newlineperformance than TiO2 due to higher electron mobility of ZnO. Moreover, newlinethe valence band of ZnO lies below the valence band of TiO2, resulting in newlinehigher oxidation potential for hydroxyl radicals generated by photo excitation of ZnO than TiO2. This infers the higher photocatalytic activity newlineof ZnO compared to TiO2. However, these metal oxides need to be newlineupgraded due to their low solar energy utilization, insufficient active sites, newlinefast charge carrier recombination rate etc.