First Principles Study of SAC and Borophene as Electrocatalysts for Water Splitting and its Origin

Abstract

The world energy problem due to increasing population and the demerits of the fossil fuel towards the climate demands an alternate fuel that is sustainable and environmentally friendly. Electrocatalysis is one of the clean processes of generating fuel. Water electrolysis through electrocatalysis is one such way to obtain clean fuel and it under research for long. Various hurdles are attributed to this process which are addressed at several levels possible. Finding a good catalyst that can solve the problem is a well-researched one. Low dimensional materials are extensively researched for their promising activity. In this thesis work, borophenes and single atom catalysts (SAC) are computationally studied for their catalytic activity towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) splitting using density functional theory (DFT). The study also focusses on exploring the properties of the material and alternate mechanism. Vacancy in borophene is correlated with electronic structure and doping is studied for OER activity. New model is proposed for H2 evolution on borophenes that addresses existing discrepancy in H2 activation energy. Multi-property-based descriptor is proposed to explain and predict the HER activity. Graphene nanoribbon-based SAC is used to study the OER activity and find a site-specific d-electron based descriptor. Possible existing d-band based descriptors are explored thoroughly, and machine learning algorithms are used to analyse large number of generated datasets. newline