ZIF-67-Derived Co₃O₄ with Dynamic Active Sites Enabling SrTiO₃ for Efficient Photocatalytic Overall Water Splitting

Developing efficient and stable non-noble metal cocatalysts represents a promising yet challenging frontier in the field of photocatalytic water splitting. Herein, ZIF-67 derived Co₃O₄ nitrogen doped graphitic carbon (Co₃O₄ NGC) is uniformly deposited onto the surface of Al-doped SrTiO₃ (STO) via an in situ growth combined with a heat treatment method. The prepared Co₃O₄ NGC/STO exhibits excellent activity for photocatalytic overall water splitting with stoichiometric H₂ and O₂ evolution, and the highest H₂ evolution rate reaches 1099 μmol h^-1 g^-1 with an apparent quantum yield of 9.27% at 365 nm, which is even higher than that of Pt loaded STO. In situ X-ray photoelectron spectroscopy accompanied by comprehensive characterizations demonstrate that the photogenerated electrons and holes respectively accumulate at Co₃O₄ NGC and STO as driven by interfacial electric field, and Co₃O₄ NGC containing Co³⁺/Co²⁺ redox couples acts as dynamic active sites to significantly reduce the energy barrier for water splitting.