Regulating charge distribution of Ru atoms in ruthenium phosphide/carbon nitride/carbon for promoting hydrogen evolution reaction

Abstract

Achieving highly efficient and durable electrocatalysts is a major challenge for hydrogen evolution reaction (HER) in full-pH-range. Modulating charge distribution of active sites in electrocatalyst is a valid strategy to attain highly efficient HER electrocatalysts. Herein, ruthenium phosphide/carbon nitride/carbon (RuP/CN/C) is successfully synthesized, in which the charges of ruthenium and nitrogen atoms are strongly redistributed. The N atom with higher electronegativity attracts electrons from active Ru atom to optimize the H* absorption behaviors on active sites surface, consequently accelerating the HER kinetics. Compared with the RuP/C, the resultant RuP/CN/C delivers low overpotential of 30.0 mV, 60.0 mV, and 30.0 mV to derive the 10 mA·cm−2 in 1.0 M KOH, 1.0 M PBS and 0.5 M H2SO4, respectively, as well as shows a remarkable stability. Furthermore, the RuP/CN/C Ⅱ RuO2 affords a low cell voltage of 1.59 V to reach the 10 mA·cm−2 against the Pt/C Ⅱ RuO2 (1.64 V) in overall water splitting. This work proposes a feasible method to construct a robust electrocatalysts for HER in full pH range.