Novel Strategies for Efficient Water Electrolysis

Abstract

A growing global population in parallel with an increased prosperity seen from a global perspective have raised the need for energy and raw material resources exponentially. These increased needs have led to a number of negative consequences such as pollution, raw material shortages, increasing carbon dioxide levels in the atmosphere, and not least a threatening global warming. Renewable energy will be essential to break the dependence of fossil fuels, but due to the intermittency of renewables a storable non-fossil alternative is needed. Hydrogen represents one of very few sustainable options to store renewable energy on large scale and for seasonal variations. Here, we present novel strategies on water electrolysis driven by photovoltaics, with a focus on the development of state-of the art electrocatalysts based on earth-abundant transition metals, doped with sulphur and phosphor [1]. We show that by tuning parameters such as adsorption energy, morphology and conductance of the electrocatalysts we can achieve solar-to hydrogen efficiency approaching 20 % [2]. We discuss on strategies, mechanisms and challenges in the field of PV-driven electrolysis.[1] Ekspong, J; Larsen, C; Stenberg, J;, Kwong, WL; Wang, J; Zhang, J; Johansson, EM; Messinger, J; Edman, L; Wagberg T, Solar-Driven Water Splitting at 13.8% Solar-to-Hydrogen Efficiency by an Earth-Abundant Electrolyzer, ACS Sustainable Chemistry & Engineering, sc-2021-03565f (acssuschemeng.1c03565). (2021)[2] H Zhang, A Aierke, Y Zhou, Z Ni, L Feng, A Chen, T Wågberg, G Hu, A high‐performance transition‐metal phosphide electrocatalyst for converting solar energy into hydrogen at 19.6% STH efficiency, Carbon Energy, 5 (1), e217 (2022)