Interface oxygen vacancy enhanced alkaline hydrogen evolution activity of cobalt-iron phosphide/CeO2 hollow nanorods

Electrocatalytic hydrogen evolution reaction (HER) is a promising way to develop the green hydrogen economy. Transition metal phosphides (TMPs) based hybrids are potential catalyst candidates for HER. Herein, hollow hexagonal rods (HHRs) of Co-Fe-P/CeO2 heterojunctions are fabricated using the metal–organic frameworks (MOFs) as the templates. The hollow frame provides abundant active sites and sufficient mass transfer, the interfacial synergistic effects and the oxygen vacancies at the interface could modulate the electronic structure, improve the water dissociation, and optimize the hydrogen adsorption free energy (ΔGH*). As a result, the Co-Fe-P/CeO2 HHRs nanohybrids exhibit excellent HER performances, for which a current density of 10 mA cm−2 can be obtained at an overpotential of only 69.7 mV in alkaline medium, together with good long-term durability. The results supply the novel platform and useful guidelines for design and construction of non-noble metal based composite electrocatalysts towards HER.