Architecture of Biperovskite-Based LaCrO3/PbTiO3 p–n Heterojunction with a Strong Interface for Enhanced Charge Anti-recombination Process and Visible Light-Induced Photocatalytic Reactions

Erection of a resourceful p–n heterojunction is a state-of-the-art tactic to flourish the charge anti-recombination process at the heterojunction interface and boost the photocatalytic activities under visible light irradiation. In the present work, we have engineered a new series of PbTiO3/LaCrO3 (PT/LC) p–n heterojunction through a facile two-step combustion process. The structural, interface, and optical analysis distinctly revealed a strong intact between p-type LaCrO3 and n-type PbTiO3, elucidating their electronic channelization and substantial reduction of electron–hole recombination at the PbTiO3/LaCrO3 interface, which extend the lifetime and population of photogenerated charges in the p–n heterojunction material. The asymmetry photocurrent in the opposite directions and an inverted characteristic V-shape Mott–Schottky plot of the optimal PT/LC (7/3) material demonstrated the construction of a p–n heterojunction. The optimal p–n heterojunction possesses excellent photostability, and it revealed the highest photocatalytic activity toward degradation of phenol, that is, 86% and hydrogen generation, that is, 343.57 μmol in 2 h. The enhanced photocatalytic activities of the p–n heterojunction materials in comparison to pristine ones are due to the higher separation charge carriers across the p–n heterojunction interface, which was deeply elucidated by carrying out electrochemical impedance spectroscopy, time-resolved photoluminescence spectroscopy, and photoluminescence analyses. These materials pave a new way to design the interface intact photocatalyst with an ultrafast approach for migration of photoexcited electrons across the p–n heterojunction and enhance the photocatalytic activities.