Carbon dots-oriented synthesis of fungus-like CoP microspheres as a bifunctional electrocatalyst for efficient overall water splitting

Abstract The development and optimization of transition metal-based bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for high-efficient water splitting. Herein, we propose a carbon dots-oriented strategy for fabricating nitrogen-doped carbon dots/fungus-like CoP microsphere composite on Ni foam (CoP-NCDs/NF). Owing to its unique structure and the strong interactions between carbon dots and CoP, the newly developed CoP-NCDs/NF electrode exhibits significantly enhanced HER and OER bifunctional catalytic activities, with overpotentials as low as 103 and 226 mV at a current density of 10 mA cm−2, respectively. Accordingly, the CoP-NCDs/NF displays excellent overall water splitting performance with a low cell voltage of 1.55 V at 10 mA cm−2 and great stability in a two-electrode alkaline electrolyzer. This study provides an alternative pathway on rationally designing and fabricating carbon dots-based materials for high performance water electrolysis and other energy conversion fields.