Doping Sr and Introducing Oxygen Vacancies in Ba0.7Sr0.3TiO3‐X Synergistically Promote the Pyro‐Photo‐Electric Catalysis Performance

The low utilization of light and the severe recombination of charge carriers have always restricted the development of photoelectric catalysis. In this work, the photoelectric catalytic performance is tuned by doping Sr in BaTiO3 pyroelectric material and simultaneously introducing oxygen vacancies to form double‐type defects, combined with pyroelectric polarization. Under the light and 20–50 °C cold‐heat cycle, the current density of Ba0.7Sr0.3TiO3‐X reaches the maximum of 0.92 mA ⋅ cm−2, which is higher than the current density of Ba0.7Sr0.3TiO3‐X under only light (0.69 mA ⋅ cm−2). Under light alone, the current density of Ba0.7Sr0.3TiO3‐X is higher than that of BaTiO3 (0.19 mA ⋅ cm−2) and Ba0.7Sr0.3TiO3 (0.44 mA ⋅ cm−2). This is because the incorporation of Sr can introduce the Fermi level, improve the utilization rate of solar energy, and improve the pyroelectric polarization effect with volume shrinkage, and promote the separation and transfer of carriers. Oxygen vacancies can be used as reactive centers for excited electrons to suppress the recombination of excited electron‐hole pairs. Furthermore, the generation of photogenerated and pyrogenerated carriers increases the overall carrier concentration. This provides ideas for the modification of traditional photoelectrodes for photoelectric catalysis water splitting. Ba0.7Sr0.3TiO3‐X was used as photoanode in PEC water splitting. The formation of Ba0.7Sr0.3TiO3‐X enhances separation efficiency of photoinduced carriers and broadens the light response range. The incorporation of Sr can introduce the Fermi level, improve the utilization rate of solar energy, and improve the pyroelectric polarization effect with volume shrinkage, and promote the separation and transfer of carriers. Oxygen vacancies can be used as reactive centers for excited electrons to suppress the recombination of excited electron‐hole pairs. Furthermore, the generation of photogenerated and pyrogenerated carriers increases the overall carrier concentration. The dual‐type doping structure can significantly improve the PEC performance of BaTiO3.