Multi-phase heterostructure of NiCoP/WP/Co2P4O12 for promoted alkaline hydrogen evolution activity

Developing economical electrocatalysts for hydrogen evolution in alkaline electrolyte, which holds rapid kinetics and long-term durability, still remains a significant challenge. Herein, an original multi-phase heterostructure of NiCoP/WP/Co 2 P 4 O 12 derived from layered double hydroxide (LDH) was synthesized through hydrothermal reaction followed by phosphation treatment. It possesses a hollow nanoflower morphology and a large specific surface area, thereby leading to the exposure of abundant active sites. More importantly, three crystalline phases and amorphous state are present in the NiCoP/WP/Co 2 P 4 O 12 catalyst, which endows it with remarkable hydrogen evolution reaction (HER) catalytic activity. In particular, the HER performance of NiCoP/WP/Co 2 P 4 O 12 exhibits low overpotentials of 105 and 133 mV at current density of 50 and 100 mA cm −2 in alkaline electrolyte, respectively, which are lower than that of most reported transition-metal catalysts. Fast reaction kinetics-mediated by NiCoP/WP/Co 2 P 4 O 12 were achieved with the low Tafel slope of 62.5 mV dec −1 . Furthermore, the multi-phase heterostructured NiCoP/WP/Co 2 P 4 O 12 shows outstanding stability, as demonstrated by electrochemical cycling tests (10,000 cycles) and a prolonged chronoamperometric test lasting 83 h. This work not only sheds new light on the HER mechanism of heterostructured electrocatalysts, but also paves the way for the rational design of non-precious and earth-rich electrocatalysts with remarkable HER catalytic activity for practical applications.