Non-metallic surface-modified X-Cu (X = F, Cl, Br) metal catalysts for all-pH hydrogen evolution reaction with high performance.

Abstract

Producing hydrogen through water electrolysis represents a clean and sustainable solution that is crucial in addressing the energy crisis. Nonetheless, the slow process of water electrolysis leads to large different kinetics for hydrogen evolution reaction (HER) under different pH solutions. Here, we designed surface modified metallic X-Cu catalysts (X = F, Cl, Br) with different non-metallic elements on nickel foam (NF) using an electrochemical deposition method, which realizes high performance for all-pH range. In 1.0 M KOH, 1.0 M phosphate-buffered saline (PBS), and 0.5 M H₂SO₄ media, F-Cu catalyst reaches 10 mA cm^-2 with overpotentials of 56 mV, 110 mV, and 197 mV, respectively. Theoretical calculations disclose that the surface modification of F atom leads to redistribution of electrons, causing an upward shift of Cu's d-band center and enhanced adsorption ability for H₂O and H intermediates (H*). This work offers novel perspectives for designing Cu-based catalysts with high HER performance, making them applicable across all-pH conditions.