2D Z-scheme heterojunction and oxygen deficiency synergistically boosting the photocatalytic activity of a layered BaTiO₃/BiOIO₃ composite

Simultaneously enhancing the quantity, separation efficiency and redox capability of photo-excited carriers to boost the catalytic activity has always been the toughest challenge for a photocatalyst. Herein, we presented a novel BaTiO₃/BiOIO₃ layered composite by proposing a synergistic strategy of 2D Z-scheme heterojunction and rich oxygen deficiency. Due to the high-quality interfaces with strong coupling interaction and stable IO₃⁻/I⁻ redox pairs between BaTiO₃ and BiOIO₃ layers, the composite was endowed concurrently with the strengthened photo response, separation efficiency and high redox capability of photo-excited carriers through a Z-scheme migration pathway. DFT computation emphasized that the formation of IO₃⁻/I⁻ redox pair and band gap of the composite were highly related to oxygen deficiency. Moreover, the ·O₂⁻ radicals can be expansively stimulated by the well-known local surface plasmon resonance effect of oxygen deficiency via inducing extra hot electrons. As a result, the composite performed a 4.4-fold enhanced photocatalytic activity than pure BaTiO₃ toward the photo-degradation of tetracycline, which can be completed in just a few minutes. Therefore, we hope that the proposed heterojunction and oxygen deficiency synergistic boosting the photocatalytic activity of BaTiO₃ could open a lot of insights for developing more efficient composite photocatalysts to solve the water pollutions.