CeO2-modulated CoP derived from prussian blue analogue boosting hydrogen evolution reaction electrocatalysis

Molecular hydrogen has been considered as ideal energy carrier due to its high calorific value and clean product, which also requires eco-friendly generation process. Electrocatalytic H2 evolution from water splitting represents a compelling sustainable and green energy technology, but it is severely hindered by the large overpotential needed, especially for non-noble metal electrocatalysts. In this study, an interface engineering strategy is extended to improve the catalytic hydrogen evolution reaction (HER) performance of CoP by introducing CeO2 component. The novel heterostructure of CoP/CeO2 is successfully fabricated by a selective phosphidation treatment of pre-synthesized Co-PBA/CeO2 hybrid precursor. The introduced CoP/CeO2 hetero-interface would regulate the electronic structure, accelerate charge transfer and enhance the intrinsic activity of the active sites. By optimizing the content of functional CeO2 entity, the CoP/CeO2-2.5 is the most active electrocatalyst with the lowest overpotential of 152 mV to reach 10 mA cm−2 current in 1.0 M KOH, as well as a Tafel slope of 83.5 mV dec−1. Besides, CoP/CeO2-2.5 can also continuously operate well for more than 16 h, demonstrating the good durability of this electrocatalyst. This work would broaden the advanced HER electrocatalysts by fabricating hetero-interface with different functional components.