Doping of W Ions to Modulate the Polarization Intensity of Bi2WO6 for Efficient Piezoelectric–Photoelechochemical Water Splitting

作者：Jingke You, Zhifeng Liu, Zhengang Guo, Mengnan Ruan, Weiguo Yan · 发表于：ACS Applied Energy Materials · 年份：2022 · DOI：10.1021/acsaem.2c01917 · 被引用次数：42 · 研究领域：Advanced Photocatalysis Techniques、Perovskite Materials and Applications、Multiferroics and related materials

The built-in electric field induced by piezoelectric polarization is an important method to effectively improve the inefficient charge transport of photoelectrochemical (PEC) water splitting. Here, we introduce a certain amount of W 5+ into Bi 2 WO 6 crystal to modulate its piezoelectric polarization performance, thus improving its piezoelectric internal electric field to drive the separation of carriers to improve the piezoelectric photoelectrochemical (piezo-PEC) water splitting. The doping of W 5+ ion widens the visible light response of the sample on the one hand, and increases the free charge density in Bi 2 WO 6 nanosheets on the other hand, thereby improving the charge transfer efficiency. The Bi 2 WO 6 -2 sample exhibits the best photochemical properties, and the photocurrent density was 0.126 mA/cm 2 at 1.23 V vs RHE. In addition, under ultrasonic conditions, the current of the Bi 2 WO 6 -2 photoelectrode was enhanced to 0.181 mA/cm 2 at 1.23 V vs RHE. The effect of ion doping on piezo-PEC performance was further explained by comparing the PEC performance of the samples before and after the introduction of the piezoelectric built-in electric field. This work suggests future uses for Bi 2 WO 6 piezo-PEC water splitting.