Oxygen vacancy and pyroelectric polarization collaboratively enhancing PEC performance in BaTiO3 photoelectrodes.

The efficient separation and transfer of electrons-holes is a key problem in photoelectric catalysis. Herein, oxygen vacancies are introduced into BaTiO 3 and combined with pyroelectric polarization to regulate the photoelectric catalytic performance, improving the separation efficiency of carriers. Under 20–50 °C hot-cold cycle, illumination and bias, the maximum current density of BaTiO 3−X -5% after oxygen vacancies introduced is 0.77 mA·cm−2, which is higher than the current density of BaTiO 3 under light alone (0.17 mA·cm−2), and the current density of BaTiO 3 under temperature fluctuation and light (0.35 mA·cm−2). This is because oxygen vacancies are characterized by prolonged light absorption and improved the use utilization of solar energy, it can be used as the capture center of excited electrons to inhibit excited electron-hole pairs recombination. In addition, the generation of photogenerated and pyrogenerated carriers increases the total carrier concentration, and the formation of polarized electric field promotes the separation and transfer of carriers. This offers an idea for development of high performance photoelectrodes in photoelectric catalytic water splitting. [Display omitted] • Pyro-photo-electric catalysis of BaTiO 3 pyroelectric materials with oxygen vacancies is studied in water splitting. • The PEC performance of BaTiO 3 is improved with the assist of pyroelectric effect and oxygen vacancies. • Oxygen vacancies can improve solar energy utilization and inhibit carrier recombination as electron capture centers. • Polarization field of pyroelectric effect promotes the separation and transfer of carriers. • Pyroelectric assisted photoelectric catalysis can realize the utilization of thermal and solar energy. [ABSTRACT FROM AUTHOR]