Single-Particle Imaging Photoinduced Charge Transfer of Ferroelectric Polarized Heterostructures for Photocatalysis.

Li, Bei; Lv, Min; Zhang, Yujia; Gong, Xueqin; Lou, Zaizhu; Wang, Zeyan; Liu, Yuanyuan; Wang, Peng et al. · ACS Nano · 2024

basic_science · Level V

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Abstract

Piezoelectric-assisted photocatalysis has a huge potential in solving the energy shortage and environmental pollution problems, and imaging their detailed charge-transfer process can provide in-depth understanding for the development of high-active piezo-photocatalysts; however, it is still challenging. Herein, topotactic heterostructures of TiO<sub>2</sub>@BaTiO<sub>3</sub> (TO@BTO-S) were constructed by the epitaxial growth of ferroelectric BaTiO<sub>3</sub> mesocrystals on TiO<sub>2</sub>-{001} facets, resulting in a ferroelectric photocatalyst with a polarization orientation on the surface. Notably, the photoinduced charge transfer in ferroelectric TiO<sub>2</sub>@BaTiO<sub>3</sub> was accurately monitored and directly visualized at the single-particle level by the advanced photoluminescence (PL) imaging microscopy systems. The longer PL lifetime of TO@BTO-S demonstrated the efficient charge separation caused by a built-in electric field, which is constructed by the polarization orientation of BaTiO<sub>3</sub> mesocrystals. Therefore, the TO@BTO-S heterostructure exhibits efficient piezoelectric-assisted photocatalytic pure water splitting, which is 290 times higher than photocatalysis. This work revealed time/spatial-resolved photoinduced charge transfer in piezoelectric assistance photocatalysts at the single-particle level and demonstrated the great role of polarization orientation in promoting charge transfer for photocatalysis.