Vacancies and phosphorus atoms assembled in amorphous urchin-like Co3O4 for highly efficient overall water splitting

Abstract

Designing highly efficient and low-cost electrocatalysts is essential for water splitting. Herein, urchin-like Co3O4 microspheres are firstly grown on nickel foam by a hydrothermal method, then Oxygen vacancies, phosphorus doping are effectively assembled in Co3O4 electrocatalysts. The introduction of oxygen vacancies and phosphorus doping will adjust the electronic structure of Co which increase the intrinsic catalytic activity and improve the adsorption energy of intermediates, simultaneously, progressively transform the crystal into randomly arranged atoms structure with short range order resulting in more active sites participate in the catalytic reaction. Moreover, the catalyst of vacancies Co3O4-Ov and phosphorus doping Co3O4–P demonstrate excellent performance in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media, Co3O4-Ov sample served as anode while Co3O4–P as cathode to form an electrolytic cell needs only 1.58 V to reach 20 mA cm−2 for overall water splitting.