Oxygen-vacancy-rich TiO2 enables highly active and durable water electrolysis of urchin-like RuO2 catalyst

The material innovation is prerequisite to accelerating sluggish oxygen evolution reaction (OER) kinetics, thus promoting the realization of hydrogen energy community. Herein, we develop an oxygen-vacancy-rich TiO 2 supported RuO 2 catalyst (RuO 2 @r-TiO 2 ) towards improved OER activity and stability. The oxygen vacancy on TiO 2 not only supplies electrons to produce lower valence Ru, but also provides sufficient anchoring site for the deposition of RuO 2 nanocrystal. Beyond that, it can generate strong electronic interaction between TiO 2 and supported RuO 2 , and thereby tailors the intermediates’ adsorption energy on the RuO 2 surface. As a result, the derived RuO 2 @r-TiO 2 catalyst exhibits superior OER activity and stability with the overpotential of 211 mV at a current density of 10 mA cm −2 and negligible activity degradation after 6 h operation, outperforming the non-oxygen-vacancy counterpart (223.3 mV, 12.75% activity loss) and RuO 2 catalyst (234.6 mV, 42.86% activity loss).