Coupling pyroelectric fields and donor doping to adjust Curie temperature and band structure to access to highly efficient BaTiO3 photoelectrodes for dye degradation

Abstract

Utilizing the pyroelectric and photoelectric properties of ferroelectric semiconductors for pollutant degradation represents an emerging, clean, and sustainable dye degradation technology. However, conventional modification methods, such as defect/morphology engineering and cocatalyst loading, can only incrementally enhance the structural and electronic states of materials to improve their catalytic performance. This study demonstrates that in pyro-photoelectrocatalysis, by introducing isovalent lanthanide ions into BaTiO₃ fundamentally reduces the Curie temperature (Tc) of BaTiO₃, thereby significantly enhancing the pyroelectric performance of Ba_1−xLa_xTiO₃ at room temperature. Furthermore, we also confirm that the introduction of heterovalent ions alters the grain size, meanwhile, we verify the change in the band structure of BaTiO₃ through Mott-Schottky plot and UV–visible absorption date. With an x value of 0.2, under the synergistic effect of thermal and photoelectric catalysis, the degradation efficiency for Rhodamine B (RhB) is optimal, reaching 98.8 % within 60 min. Additionally, the pyro-photoelectrocatalysis measured under 1.23 V shows that Ba_0.8La_0.2TiO₃ (0.073 mA/cm²) exhibits a pyro-photoelectrocatalysis current 1.6 times higher than that of pure BaTiO₃(0.048 mA/cm²), this research provides a viable method for designing electrodes with superior pyro-photoelectrocatalysis performance.