Unraveling the Transformation from Type-II to Z-Scheme in Perovskite-Based Heterostructures for Enhanced Photocatalytic CO 2 Reduction

作者：Wentao Song, Kok Chan Chong, Guobin Qi, Yukun Xiao, Ganwen Chen, Bowen Li, Yufu Tang, Xinyue Zhang, Yingfang Yao, Zhiqun Lin, Zhigang Zou, Bin Liu · 发表于：Journal of the American Chemical Society · 年份：2024 · DOI：10.1021/jacs.3c12073 · 被引用次数：295 · 研究领域：Perovskite Materials and Applications、Advanced Photocatalysis Techniques、Electronic and Structural Properties of Oxides

The ability to create perovskite-based heterostructures with desirable charge transfer characteristics represents an important endeavor to render a set of perovskite materials and devices with tunable optoelectronic properties. However, due to similar material selection and band alignment in type-II and Z-scheme heterostructures, it remains challenging to obtain perovskite-based heterostructures with a favorable electron transfer pathway for photocatalysis. Herein, we report a robust tailoring of effective charge transfer pathway in perovskite-based heterostructures via a type-II to Z-scheme transformation for highly efficient and selective photocatalytic CO 2 reduction. Specifically, CsPbBr 3 /TiO 2 and CsPbBr 3 /Au/TiO 2 heterostructures are synthesized and then investigated by ultrafast spectroscopy. Moreover, taking CsPbBr 3 /TiO 2 and CsPbBr 3 /Au/TiO 2 as examples, operando experiments and theoretical calculations confirm that the type-II heterostructure could be readily transformed into a Z-scheme heterostructure through establishing a low-resistance Ohmic contact, which indicates that a fast electron transfer pathway is crucial in Z-scheme construction, as further demonstrated by CsPbBr 3 /Ag/TiO 2 and CsPbBr 3 /MoS 2 heterostructures. In contrast to pristine CsPbBr 3 and CsPbBr 3 /TiO 2, the CsPbBr 3 /Au/TiO 2 heterostructure exhibits 5.4- and 3.0-fold enhancement of electron consumption rate in photocatalytic CO 2 reduction. DFT calculations and in situ diffuse refl...