Evaluation metrics and essential design strategies in developing electrode materials for a water-splitting process

Clean and efficient hydrogen fuel as the future energy source for decarbonizing and establishing a sustainable carbon-neutral economy is highly attractive. Notable progress in hydrogen production through water splitting has been conducted to achieve zero carbon emissions, safety, and high product purity. Despite advancements, challenges like a significant large energy barrier with high cost associated with water splitting still exist. Efficient electrocatalysts have been designed to address the challenges of water splitting. Those catalysts aim to reduce energy barriers and costs associated with the process. Nevertheless, there are still challenges in promoting the industrialization of electrocatalytic water splitting. This review discusses the latest progress in water electrolysis, incorporating experimental evidence from in-situ spectroscopic surveys and computational analyses to provide a mechanistic understanding of hydrogen and oxygen evolution reactions. Various evaluation metrics and essential strategies are highlighted for designing and fabricating efficient electrocatalysts, including alloying, morphological engineering, interface construction, defect engineering, and strain engineering. This work aims to provide a knowledge-guided design in fundamental science, offering insights that could inspire technical engineering developments to build efficient electrocatalysts for water splitting.