Bi Vacancy-Induced Bi2o2s Nanosheets for Remarkably Boosting Piezocatalytic Performance

Abstract

Defect engineering is an efficient strategy to address piezoelectric-catalyzed degradation, but metal cation defects introduced in crystals have rarely been reported, owing to the formation of cationic defects requiring higher energy than that of anionic defects. Herein, Bi vacancy-induced Bi2O2S (BOS) nanosheets were synthesized for the piezoelectric-catalyzed degradation of organic dyes, utilizing a low-temperature solid-state reduction method with the help of NaBH4 for the first time. Astonishingly, Bi2O2S (BOS-4) with a large number of Bi vacancies exhibited an impressive 95.69% degradation rate for rhodamine B (RhB) under ultrasound, approximately three times higher than that achieved by BOS. Additionally, BOS-4 also effectively degrades other dyes as well. This phenomenon is mainly ascribed to reduced band gap and facilitated the generation of charges by the introduced Bi vacancies, which can attract negative charges move in a definite direction and promote effective charge separation, thereby improving piezcatalytic efficiency. This research introduces a pioneering approach to introduce Bi vacancy in Bi2O2S enabling an efficient electron transfer process, while confirming the introduction of cationic vacancy can employ as an innovative means to construct piezoelectric catalyst.

Keywords: Bi2O2S nanosheets, Bismuth vacancies, Piezocatalysis, Degradation of organic pollutants