Highly effective and durable integrated‐chainmail electrode for H2 production through H2S electrolysis

H₂S is a prevalent yet toxic gas commonly encountered during fossil fuel extraction, whose electrolysis not only addresses pollution concerns but also facilitates hydrogen production. However, the advancement of H₂S electrolysis at high current density has been impeded by the lack of stable and highly active electrodes that can endure the corrosive effects of H₂S poisoning. Herein, we present an integrated‐chainmail electrode that features dual‐level chainmail structure with graphene encapsulating nickel foam (Ni@NC foam) to enhance H₂S electrolysis. The electrode comprises a primary chainmail, formed by graphene coating on the surface of nickel foam, and a secondary chainmail, created by graphene encapsulating nickel nanoparticles. This integrated‐chainmail structure significantly enhances both the activity and stability of nickel foam, which delivers an industrial‐scale high current density exceeding 1 A cm⁻² at 1.12 V versus reversible hydrogen electrode, above five times higher than nickel foam. Moreover, the Ni@NC foam remains stable over 300 hours of test, demonstrating a lifespan at least ten times longer than nickel foam. In a demo for H₂S removal from simulated natural gas, the Ni@NC foam as the electrodes exhibits a hydrogen production rate of 272 ml min⁻¹, while reducing electricity consumption by 43% compared with traditional water electrolysis.