Highly efficient nanosized MoS2/MoP heterocatalyst for enhancing hydrogen evolution reaction over a wide pH range

Abstract

Energy consumption associated with the catalysts contributes partly to the high ohmic resistance arising from the low conductivity of the catalyst and poor charge transfer between nanoparticles, which has been difficult to study due to the complicated nanostructured framework of the catalysts. We constructed a novel heterostructure electrocatalyst (MoS₂/MoP@NC) composed of nanosized MoS₂/MoP heterostructures anchoring on hierarchical N-doped carbon for smoothing electron transfer in boosting hydrogen evolution reaction (HER). With the merits of large surface area, rapid charge transfer, and optimized electronic structure induced by charge transfer across the sufficient interface, the optimal MoS₂/MoP@NC (MoSP) catalyst shows a competitive overpotential of 140 (0.5 M H₂SO₄), 76 (1.0 M KOH), and 103 mV (0.5 M NaCl &1.0 M KOH) at 10 mA cm⁻², respectively. Raman experiment and Density functional theory (DFT) calculations reveal the formation of Mo-S-Mo bonds between MoS₂ and MoP, which favor enhancing the Femi level to facilitate the electron transfer, therefore regulating the electronic structure for the optimization of adsorption energy of hydrogen intermediate. Based on the experimental results, we constructed an energy consumption model of catalysts, where energy consumption comes from three aspects. The heterostructure design decreases the energy consumption of the catalysts greatly compared to the single-phase Mo-based catalyst of MoS₂ (78.0%) and MoP (45.2%) in alkaline electrolytes.