Gradient tungsten-doped Bi3TiNbO9 ferroelectric photocatalysts with additional built-in electric field for efficient overall water splitting

作者：Jie Huang, Yuyang Kang, Jianan Liu, Tingting Yao, Jianhang Qiu, Peipei Du, Biaohong Huang, Weijin Hu, Yan Liang, Tengfeng Xie, Chunlin Chen, Lichang Yin, Lianzhou Wang, Hui–Ming Cheng, Gang Liu · 发表于：Nature Communications · 年份：2023 · DOI：10.1038/s41467-023-43837-4 · 被引用次数：113 · 研究领域：Multiferroics and related materials、Advanced Photocatalysis Techniques、Ferroelectric and Piezoelectric Materials

Abstract Bi 3 TiNbO 9 , a layered ferroelectric photocatalyst, exhibits great potential for overall water splitting through efficient intralayer separation of photogenerated carriers motivated by a depolarization field along the in-plane a -axis. However, the poor interlayer transport of carriers along the out-of-plane c -axis, caused by the significant potential barrier between layers, leads to a high probability of carrier recombination and consequently results in low photocatalytic activity. Here, we have developed an efficient photocatalyst consisting of Bi 3 TiNbO 9 nanosheets with a gradient tungsten (W) doping along the c -axis. This results in the generation of an additional electric field along the c -axis and simultaneously enhances the magnitude of depolarization field within the layers along the a -axis due to strengthened structural distortion. The combination of the built-in field along the c -axis and polarization along the a -axis can effectively facilitate the anisotropic migration of photogenerated electrons and holes to the basal {001} surface and lateral {110} surface of the nanosheets, respectively, enabling desirable spatial separation of carriers. Hence, the W-doped Bi 3 TiNbO 9 ferroelectric photocatalyst with Rh/Cr 2 O 3 cocatalyst achieves an efficient and durable overall water splitting feature, thereby providing an effective pathway for designing excellent layered ferroelectric photocatalysts.