Ultrafine Co-doped RuO₂ nanoparticles loaded on N-TiO₂ as a bifunctional electrocatalyst with wide pH adaptability

Abstract

The development of high-performance electrocatalysts is a crucial prerequisite for green hydrogen production through water-splitting. In this work, a bifunctional electrocatalyst (Co-RuO2/N-TiO2) with superdispersed heterojunction structure was prepared by loading ultrafine Co doped RuO2 nanoparticles on the surface of N-TiO2. The ultrafine Co-RuO2 nanoparticles achieve a superdispersion effect, allowing their active sites to be fully exposed. In addition, doping and heterojunction strategies promote charge transfer between materials, thereby optimizing the electronic structure of the final catalyst and improving catalytic activity and stability. The results showed that Co-RuO2/N-TiO2 exhibited excellent bifunctional catalytic performance, with overpotentials of 50 mV and 195 mV for HER and OER reactions at a current density of 10 mA cm-2 in 0.5 M H2SO4, respectively. In 1 M KOH, Co-RuO2/N-TiO2 still exhibits excellent HER and OER catalytic performance, with overpotentials of 16 mV and 269 mV at 10 mA cm-2, respectively. Whether under acidic or alkaline conditions, Co-RuO2/N-TiO2 exhibits good stability and rapid reaction kinetics in catalyzing OER and HER reactions.