Efficient electron channel at the TiO₂/BaTiO₃ nanodots interface for enhanced CO2 photoreduction

Abstract

Unraveling electron transport channels across S-scheme heterostructures constitutes a pivotal research focus in advancing photocatalysis. Herein, an in-situ growth method prepares an island-shaped TiO2/BaTiO3 (TB) heterojunction. During the in-situ growth process, the Ba2+ penetrate into the TiO2 surface and fabricates the BaTiO3 phase, which constructs electron channels. Due to this strategy, the photogenerated electrons of TiO2 transfer to the valence band of BaTiO3 via the electron transport channels, while the photogenerated electrons accumulate on the conduction band of BaTiO3 to reduce CO2. Owing to the efficient electron transport channel at the BaTiO3 nanodots interfaces, the performance of the optimized TB sample is greatly improved to 45.4 μmol g-1 h-1 for CO2-to-CO and 173.3 μmol g-1 h-1 for CO2-to-CH4, with a 93.9% CH4 electron selectivity. Characterizations and theoretical calculations show that the interface constructs an electron transport channel and accelerates the transfer of photogenerated electrons. This work proposes an in-situ strategy to construct island-type S-scheme interfaces with directional charge-transfer channels, enabling efficient photocatalytic performance.