Unlocking the catalytic potential of NbB2 via vacancy creation and ruthenium decoration for efficient electrocatalytic water splitting

The development of efficient and durable bifunctional electrocatalysts for overall water splitting remains a key challenge for sustainable hydrogen production. In this study, a novel strategy is proposed to synergistically design boron vacancies and integrate Ru species into NbB 2 (Ru/RuO 2 -NbB 2 -v) by calcination and immersion methods. NbB 2 with its intrinsic high conductivity facilitates to electron transport and improves the reaction kinetics of the catalyst. The strategic introduction of abundant B vacancy and Ru species can expose numerous active sites and lower the reaction energy barriers in the materials, thereby enhancing the reactivity of the catalysts. Impressively, Ru/RuO 2 -NbB 2 -v exhibited superior hydrogen evolution reaction (HER) activity in wide pH range. In addition, Ru/RuO 2 -NbB 2 -v also exhibits good oxygen evolution reaction (OER) performance in acidic and alkaline. A self-assembled electrolyzer driven by simulated solar energy enables the conversion of solar energy into hydrogen energy. The work pioneers a defect-engineering and noble-metal-decoration strategy to transform metal borides into versatile electrocatalysts, offering a scalable pathway for clean energy technologies.