Enhanced electrocatalytic water splitting by adjusting the local reaction environment with nickel coordination regulation

Electrocatalytic water splitting is a promising route to produce hydrogen under mild conditions. Local reaction environment regulation via electrochemical activation is one of the most promising ways to achieve excellent hydrogen evolution reaction (HER) catalytic activity. Electrochemical activation technology compared with traditional synthetic technology has many advantages, such as low energy consumption, fast reaction speed, simple experimental operation, and reducing energy and environmental problems. However, the mechanism of adjusting the local reaction environment remains unclear. Here, we use a simple electrochemical activation method to control the Ni5P4 particles on the nickel surface to achieve the regulation of the local reaction environment. It is found that electrochemical activation could effectively improve the catalytic activity, with hydrogen evolution overpotential of 87 mV at 10 mA cm−2. Both electrochemical measurements and theoretical calculation demonstrate the important role of in situ electrochemical activations for intermediate adsorption and desorption via nickel coordination regulation. Our strategy of adjusting the local reaction environment with nickel coordination regulation merging interfacial may create a promising pathway to developing the HER performance of metal phosphide. [Display omitted] •Electrochemical activation was used for Ni coordination regulation.•Ni with Ni5P4 particles exhibits excellent HER activity.•Local reaction environment adjusting mechanism was studied.