Interface Engineering of CoP3/Ni2P for Boosting the Wide pH Range Water-Splitting Activity

Developing electrocatalysts with low price, high energy efficiency, and universal pH value for hydrogen/oxygen evolution reaction (HER and OER) is very important for the wide application of electrochemical water splitting in hydrogen production. The results of density functional theory show that the interface region of CoP3/Ni2P heterostructures can significantly boost all of the catalytic performances. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to confirm the abundant structural defects and the corresponding adjustment of the electronic state, thus ameliorating the activation energy, conductivity, and active area of the catalyst. Benefiting from these, CoP3/Ni2P heterostructures exhibit superior performance of both HER and OER in a wide pH range. CoP3/Ni2P can also be used for water splitting (1.557 V at 10 mA cm(-2)) more than 40 h, superior to benchmark pairs of Pt/C and RuO2 on Ni foam.

Automated summary

Developing electrocatalysts with low cost, high energy efficiency, and universal pH value for hydrogen/oxygen evolution reaction is crucial for electrochemical water splitting in hydrogen production. CoP3/Ni2P heterostructures show superior catalytic performance in a wide pH range due to abundant structural defects and electronic state adjustment, leading to improved activation energy, conductivity, and active area of the catalyst. This allows CoP3/Ni2P to be used for water splitting for over 40 hours at a high performance level, surpassing benchmark pairs of Pt/C and RuO2 on Ni foam.