Efficient piezocatalytic activation of peroxydisulfate over Bi <sub>2</sub> Fe <sub>4</sub> O <sub>9</sub> : thickness‐dependent synergy effect between peroxydisulfate activation and piezocatalysis
Chuangjian Su, Chaolin Li, Wenhui Wang
Abstract
Abstract Piezocatalytic activation of persulfate (PS) has great application potential in environmental remediation; however, the relationship between piezocatalyst thickness and catalytic activity is not clear, limiting the further improvement of catalytic activity and application of the technology. Herein, the Bi 2 Fe 4 O 9 (BFO) piezocatalysts with tunable thickness were prepared through a facile hydrothermal method by tuning the molar ratio of Bi(NO 3 )·5H 2 O and FeCl 3 ·6H 2 O for piezocatalytic activation of peroxydisulfate (PDS). The BFO with the smallest thickness exhibits excellent catalytic activity, and the and are the major reactive oxygen species for degrading organic pollutants. Further XPS investigations and finite element analyses demonstrate that the decreased thickness of BFO not only exposes more Fe 2+ sites for PDS activation, but also improve the piezoelectric effect to accelerate the regeneration of Fe 2+ , thus enabling an enhanced synergy effect between PDS activation and piezocatalysis for outstanding catalytic activity. This work provides an understanding of the relationship between thickness of piezocatalysts and its catalytic activity over PDS activation, facilitating the development of more efficient piezocatalysts and PS‐based advanced oxidation processes.