Electronic Modulation of RuCo Catalysts on TiO2 Nanotubes Promoting Durable Acidic Overall Water Splitting

Abstract The development of efficient and durable bifunctional electrocatalysts is essential for hydrogen production from acidic water splitting. Herein, a TiO 2 nanotube‐loaded Co‐doped Ru nanoparticle catalyst (RuCo/TiO 2 NTs) is reported that exhibits excellent activity and stability toward acidic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The Ru─O─Ti bonding is enhanced by Co doping, and the metal carrier interaction between Ru nanoparticles and TiO 2 NTs is enhanced, which effectively stabilizes Ru species during OER and initiates hydrogen spillover accelerating HER kinetics. As a result, RuCo/TiO 2 NTs catalyst requires only 156 mV OER overpotential and 17 mV HER overpotential to achieve a current density of 10 mA cm −2 with a stability more than 500 h in acidic conditions. More importantly, benefiting from the excellent bifunctional activities, the proton exchange membrane electrolyte assembled from RuCo/TiO 2 NTs has excellent activity and robust stability (1000 h). This work opens a new avenue for the efficient energy conversion devices.