Single/dual-atom electrocatalysts for water splitting related reaction at neutral pH

Abstract

The energy crisis and complex environmental issues stemming from fossil fuel consumption have propelled the development and utilization of renewable energy sources, with electrochemical water splitting (EWS) being an effective way and ideal method for producing clean and renewable energy (hydrogen). Up to now, the majority of EWS-related reactions have been studied mainly under acidic and alkaline conditions, which have achieved relatively excellent catalytic activities and efficiencies, albeit with certain safety risks, accompanied by corrosion, contamination, and the generation of waste liquids, in addition to the demand for acid- and alkali-resistant electrocatalytic materials as well as costly anion/cation-exchange membranes. To overcome these shortcomings, the development of advanced catalysts for neutral EWS becomes an attractive and more sustainable option. Unfortunately, there are relatively few theoretical discussions and practical applications of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) as well as other anodic oxidation reactions under neutral conditions. Single/dual-atom electrocatalysts (S/DACs), characterized by maximum metal utilization efficiency, homogeneous active sites, and remarkable synergistic effect, exhibit great potential for EWS-related reactions under neutral conditions. Therefore, we provide a brief mechanistic discussion of neutral HER/OER, focusing on the synthesis, modulation strategies, characterization techniques and current representative applications in EWS-related reactions under neutral conditions, as well as the challenges and prospects of S/DACs. This review may provide some insights to facilitate the practical application of efficient hydrogen production under neutral conditions.