Electronic and active site engineering in Rh metallene via phosphorus and sulfur dual-doping for electrocatalytic sulfion recycling and hydrogen generation

Abstract

Coupling the thermodynamically favorable sulfion oxidation reaction (SOR) with the hydrogen evolution reaction (HER) is a promising approach to simultaneously save energy and cost-effectively produce high value-added chemicals and hydrogen. The construction of efficient bifunctional catalysts for SOR–HER electrocatalysis is of significance yet challenging. Here, we propose a dual-nonmetal-doping strategy to construct S and P dual-doped Rh metallene (SP-Rhlene). Benefiting from the combined advantages of dual heteroatom doping and an ultrathin nanosheet structure, SP-Rhlene with a large electrochemical active area and an optimized electronic structure exhibits outstanding HER and SOR activities. A two-electrode system based on optimized SP-Rhlene only needs a cell voltage of 0.385 V at 10 mA cm⁻² to generate H₂, while transforming S²⁻ into sulfur powder, which further reduces the cost of hydrogen production and protects the ecological environment. This work provides a directive strategy for the rational construction of dual heteroatom doped metallene for energy-saving hydrogen production and environmentally friendly sulfur recovery.