Carbonized spider silk/V₂CT_x heterostructured electrocatalysts for efficient hydrogen evolution reaction

The efficiency of the electrocatalytic hydrogen evolution reaction (HER) is significantly advanced by developing proficient electrocatalysts. Herein, the novel carbonized spider silk nanofiber (SAC)/V₂CT_x heterostructured electrocatalysts (SAC/V₂CT_x) are presented, which demonstrate robust stability and superior catalytic performance. The problem of nitrogen and sulfur loss due to high-temperature self-doping is resolved by the careful modulation of the KCl activation condition, which allows the thermal carbonization of spider silk at a lower temperature than in previous reports. This results in a porous structure, a high graphitization, and an adequate nitrogen/sulfur content. The deliberate intercalation of SAC with V₂CT_x creates a heterostructure that improves charge transfer, suppresses MXene’s tendency to stack, and significantly increases the stability and activity of the catalyst. The heteroatom doping, in synergy with the SAC/V₂CT_x heterostructure, results in a low charge transfer resistance of 31.2 Ω for SAC_1.2/V₂CT_x under acidic conditions. It exhibits an overpotential of 164.3 mV at a current density of 10 mA cm⁻² and a Tafel slope of 91.4 mV dec⁻¹. The catalyst maintains over 90% of its initial activity after 50 h of operation, highlighting its durability and suitability for sustainable HER processes.