Rational design of N, S co-doped biomass-derived carbon for high-efficiency oxygen evolution reaction

The global energy situation is becoming increasingly severe, and the strategic importance of hydrogen is becoming more pronounced. Water splitting for hydrogen production is considered the most promising method for obtaining hydrogen. However, the slow reaction kinetics of both the hydrogen evolution reaction and the oxygen evolution reaction result in low electrolysis efficiency and high energy consumption in actual production. It is urgent to develop efficient and cost-effective electrocatalysts consequently. Herein, the resource-rich waste durian shells were utilized as raw materials, and nitrogen and sulfur co-doped durian shell-derived biomass carbon （NS-DC） was prepared through low-temperature doping and high-temperature carbonization, thereby achieving the re-utilization of waste biomass. Attributed to the dual doping of nitrogen and sulfur heteroatoms, the electrical conductivity of the carbon materials and the number of active defect sites achieved a good balance, NS-DC showed a significant enhancement of the electrocatalytic performance. As a catalyst for the oxygen evolution reaction, NS-DC achieved a current density of 10 mA·cm⁻² with a low overpotential of only 458 mV, excellent stability, and a Tafel slope of 92 mV·dec⁻¹, which demonstrated extraordinary charge transfer kinetics. The successful preparation of NS-DC not only confirms the feasibility of resource utilization of waste biomass, but provides new insights for the dual heteroatom doping regulation of the structure and properties of biomass-based carbon materials.