Construction of CoP2-Mo4P3/NF Heterogeneous Interfacial Electrocatalyst for Boosting Water Splitting

Developing highly efficient, cost effective and durable bifunctional electrocatalyst remains a key challenge for overall water splitting. Herein, a bifunctional catalyst CoP2-Mo4P3/NF with rich heterointerfaces was successfully prepared by a two-step hydrothermal-phosphorylation method. The synergistic interaction between CoP2and Mo4P3heterogeneous interfaces can optimize the electronic structure of active sites, leading to the weak adsorption of H on the Mo sites and the increased redox activity of the Co site, resultantly improving the HER/OER bifunctional catalytic activity. The synthesized CoP2-Mo4P3/NF catalyst exhibits excellent electrocatalytic activity in 1.0 M KOH with low overpotentials of 77.6 and 300.3 at 100 mA cm−2for HER and OER, respectively. Additionally, the assembled CoP2-Mo4P3/NF||CoP2-Mo4P3/NF electrolyzer delivers a current density of 100 mA cm−2at a cell voltage of 1.59 V and remains stable for at least 370 h at 110 mA cm−2, indicating the potential application prospective in water splitting.Keywords:heterogeneous interface;transition metal phosphide;bifunctional electrocatalyst;overall water splitting