Building CoP/Co-MOF heterostructure in 2D nanosheets for improving electrocatalytic hydrogen evolution over a wide pH range

Hydrogen has been regarded as one of promising renewable alternatives to traditional fossil fuels. It remains a big challenge to explore highly efficient catalysts with low cost for hydrogen evolution reaction (HER) in energy storage and conversion. Herein, we proposed a facile method to fabricate a self-supported electrode with two-dimensional (2D) CoP/Co-MOF heterostructure nanosheets via a partially controlled phosphorization method. The optimal 2D CoP/Co-MOF exhibits excellent HER activities over a wide pH range, which only requires 52, 106, and 26 mV overpotentials at −10 mA cm−2 in acidic (0.5 M H2SO4), neutral (1.0 M PBS) and alkaline (1.0 M KOH) solution, respectively. Additionally, CoP/Co-MOF also presents desirable durability under different pH media. The excellent HER performance can be attributed to the fast charge-transfer rate and abundant exposed active sites because of the modified electronic structure and increased specific surface area. This work provides an effective strategy to design the pH-universal HER activity of MOF-based electrocatalysts.