New vesicular carbon-based rhenium phosphides with all-pH range electrocatalytic hydrogen evolution activity

Abstract

Considering the great application prospect of noble metal rhenium (Re) in the catalytic field derived from its intrinsic properties, exploring more novel and highly effective Re-based catalysts becomes an important topic. Herein, for the first time, we design a novel strategy for fabrication of Re2P and Re3P4 nanoparticles anchored in N, P doped vesicular carbon (NPVC) via pyrolyzing ammonium perrhenate (NH4ReO4), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and melamine on the surface of SiO2 spheres. Choosing hydrogen evolution as a probe reaction, Re3P4@NPVC heterostructure exhibits highly efficient catalytic activity compared with as-synthesized samples, which rivals the commercial Pt/C. Concretely, the Tafel slope is 38, 77 and 62 mV dec−1, and overpotential is 40, 70 and 61 mV at 10 mA cm−2 in 0.5 M H2SO4, 1 M phosphate buffer solution and 1 M KOH, respectively. Both experiment and DFT calculation unambiguously validate that Coupling metal Re and P is able to promote the HER pathway by tuning the ΔGH* value close to the optimum, balancing adsorption and desorption of hydrogen. Besides, the electronic coupling of NPVC layer and NPs synergistically enhances the proton adsorption and reduction kinetics.