Charge-enriched RuO₂ nanoparticles decorating TiO₂ with Ti defects to promote oxygen evolution reaction in acidic media

Dispersing precious metal oxide nanoparticles on a support is a promising catalyst modification strategy for the oxygen evolution reaction in acidic media, but the rational design of the heterointerface remains challenging. Herein, electron-rich ruthenium dioxide dispersed on the metal-deficient TiO₂ is constructed as an efficient electrocatalyst for oxygen evolution. The combination with defective support triggers the charge transfer from the support to RuO₂, which optimizes the adsorption/desorption of oxo-intermediates and thus improves the kinetics of the OER reaction. Moreover, the large electron filling in the support, as an auxiliary, accelerates the deprotonation of oxo-intermediates during the acidic OER. As a result, the improved d-TiO₂/RuO₂ showed excellent OER activity, with an overpotential of 226 mV @10 mA cm⁻² in 0.5 M H₂SO₄, which was superior to that of commercial RuO₂. This study provides an ideal defective support for unique heterojunction catalysts and highlights the development of noble metal catalysts with low cost.