Enhancing Electrocatalytic Performance for Overall Water Splitting using Hollow Structured Fe‐doped CoP with Phosphorus Vacancies

Water electrolysis is a promising method for producing ultra‐pure hydrogen as a sustainable energy source in the future. In this study, the use of a hollow‐structured Fe‐doped CoP with an abundance of phosphorus defects for both oxygen and hydrogen evolution reactions (OER and HER) is suggested. The as‐prepared electrocatalyst has a low overpotential of 300 and 143 mV to achieve a current density of 10 mA cm −2 for the OER and HER, respectively. When the synthesized electrocatalyst is used as both anode and cathode in a water electrolyzer, the full cell requires a very small cell voltage of 1.63 V at 10 mA cm −2 and exhibits excellent stability for over 100 h. The excellent performance is due to the generation of numerous electrocatalytic active sites induced by introduction of structural defects such as Fe dopants and P vacancies, which modify the adsorption energy of reaction intermediates during water electrolysis. This study can offer new insights into the development of efficient precious metal‐free electrocatalysts for production of renewable energy sources.