Recent advances and perspective on transition metal heterogeneous catalysts for efficient electrochemical water splitting

The development of advanced technology for producing high-purity and low-cost hydrogen is crucial for the upcoming hydrogen economy. One of the most promising technologies to achieve carbon peak and carbon neutrality is hydrogen production through water electrolysis coupled with renewable energy. However, the efficiency of water electrolysis is limited by the catalyst material employed, thereby the pursuit of highly efficient catalysts is of paramount scientific significance. In this review, we focus on the synthesis of electrocatalysts for the hydrogen/oxygen evolution reaction (HER/OER) through various strategies such as hydrogen spillover, heterostructure construction, element doping, monatomic construction, LDH structure modification, high entropy alloy, and other approaches. The article also provides a comprehensive overview of the challenges encountered in enhancing the activity, stability, and durability of transition metal heterogeneous catalysts for both HER and OER. Moreover, the mechanisms of HER and OER are illustrated. The electrocatalysts prepared by these strategies have exhibited promising results in terms of water splitting performance. However, there are still unresolved issues that need to be addressed, such as improving long-term stability and reducing overall cost. Future prospects include exploring new materials and optimizing the preparation methods to further enhance the electrocatalytic activity.