Ga-SrTiO3 modified by CuCrOx/Co3O4 dual cocatalyst for efficient photocatalytic overall water splitting

Strontium titanate (SrTiO 3 ) holds great potential for photocatalytic overall water splitting (OWS) to produce hydrogen. However, the current SrTiO 3 -based photocatalysts require expensive noble metals, such as Pt and Rh. There is an urgent need to explore cost-effective alternatives using non-noble metals. Herein, Cu, Cr, and Co were used as non-noble cocatalyst to modify the surface of Ga˗doped SrTiO 3 photocatalyst (Ga-STO (flux)). The characterization results of XPS and TEM revealed the CuCrO x cocatalysts generated reduced Cu 0 /Cu + species for hydrogen evolution reaction. The inclusion of Cr 2 O 3 aided in maintaining the stability of Cu 0 /Cu + species. The Co 3 O 4 cocatalysts were responsible for the oxygen evolution reaction. Under simulated sunlight, the optimal CuCrO x /Co 3 O 4 /Ga-STO (flux) sample provided the best hydrogen and oxygen production rates of 204.56 μmol·h⁻¹ and 102.28 μmol·h⁻¹ , respectively.