Oxygen-vacancy-rich TiOenables highly active and durable water electrolysis of urchin-like RuOcatalyst

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 TiO2supported RuO2catalyst（RuO2@r-TiO2） towards improved OER activity and stability. The oxygen vacancy on Ti O2not only supplies electrons to produce lower valence Ru, but also provides sufficient anchoring site for the deposition of RuO2nanocrystal. Beyond that, it can generate strong electronic interaction between TiO2and supported RuO2, and thereby tailors the intermediates' adsorption energy on the RuO2surface. As a result, the derived RuO2@r-TiO2catalyst exhibits superior OER activity and stability with the overpotential of 211 m V at a current density of 10 mA cm-2and negligible activity degradation after 6 h operation, outperforming the non-oxygen-vacancy counterpart（223.3 mV, 12.75% activity loss） and RuO2catalyst（234.6 mV, 42.86% activity loss）.