Phosphorous and cations boost the electrocatalytic performances of Cu-based compounds for hydrogen/oxygen evolution reactions and overall water-splitting

Developing durable, effective and inexpensive electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are crucial for the advancement of water splitting as a solution to the energy shortage. In this study, nanospheres stacked into nanochains are successfully prepared by oxidative corrosive engineering, solvothermal, and following calcination process (Co-Cu3P/CF). The unique nanochain structure facilitates growing the specific surface area, thereby exposing plenitude active sites. The introduced phosphorus (P) and Co ions can alter the electronic characteristics of metal phosphides, not only can accelerate the electron transport of the catalysts, but speed up the reaction kinetics. Thus, the prepared Co-Cu3P/CF exhibits low overpotentials, with 240/84 mV, in alkaline media for OER/HER to attain 10 mA cm−2. In alkaline freshwater/seawater, the self-assembled electrolyzer needs only 1.51/1.58 V to achieve 10 mA cm−2. This work provides an approach for the preparation of high-performing and economical electrocatalysts.