Electron redistributed vanadium anchored CoFe phosphides as effective electrocatalysts for boosting overall water splitting

Abstract

Transition metal phosphides (TMPs) with platinum -like electronic construction are emerging as prospective options for hydrogen evolution reaction (HER) in alkaline conditions. Still, the robust bonding strength between TMP with the related intermediates prevents a further enhancement in its electrocatalytic activity. This paper uses V doping modification strategy to adjust the electron distribution on the surface of bimetallic phosphides and improve their HER capability. When V–CoFeP is employed as a dual functional electrocatalyst under the environment of 1 M KOH, the cathode HER performance is 53 mV (η10) and the anode oxygen evolution reaction (OER) performance is 175 mV (η50). For overall water decomposition, a dual electrode alkaline battery coupled with a dual functional electrocatalyst V–CoFeP needs only 1.845 V to achieve η50 which can hold its excellent electrocatalytic capability for 25 h. Finally, DFT calculations show that formation P vacancies and V doping induces an internal electron redistribution in V–CoFeP. Therefore, this work shows new insights for synthesizing highly active and stable electrocatalysts by adjusting the TMP electronic structure to achieve overall water decomposition.