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 a superdispersed heterojunction structure was prepared by loading ultrafine Co-doped RuO₂ nanoparticles onto 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 its 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 the HER and the OER at a current density of 10 mA cm⁻² in 0.5 M H₂SO₄, respectively. Also, in 1 M KOH, Co-RuO₂/N-TiO₂ exhibited 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 exhibited good stability and rapid reaction kinetics in catalyzing the OER and the HER.