BiFeO3 Nanoparticles: The "Holy-Grail" of Piezo-Photo-Catalysts?

Recently, piezoelectric-based catalysis has been demonstrated to be an efficient means and promising alternative to sunlight-driven photocatalysis, where mechanical vibrations trigger redox reactions. Here, we show that 60 nm average size BiFeO 3 nanoparticles are very effective for piezo-degrading Rhodamine B (RhB) model dye with record degradation rate values reaching 13810 L mol -1 min -1 , and even 41750 L mol -1 min -1 (i.e., 100% RhB degradation within 5 min) when piezocatalysis is synergistically combined with sunlight photocatalysis. We also demonstrate that these BiFeO 3 piezocatalytic nanoparticles are versatile towards several cationic and anionic dyes, and pharmaceutical pollutants, with over 80% piezo-decomposition within 120 min among the six pollutants tested. The maintained high piezoelectric coefficient combined with low dielectric constant, high elastic modulus and the nanosized shape make these BiFeO 3 nanoparticles extremely efficient piezocatalysts. To avoid subsequent secondary pollution and enable their reusability, the BiFeO 3 nanoparticles are further embedded in a polymer P(VDF-TrFE) matrix. The as-designed free standing, flexible, chemically stable and recyclable nanocomposites still keep remarkable piezocatalytic and piezo-photocatalytic performances (i.e., 92% and 100% RhB degradation, respectively, within 20 min). This work opens a new research avenue for BiFeO 3 that is the model multiferroic material, and offers a new platform for water cleaning, as well as other applications such as water splitting, CO 2 reduction or surface purification. This article is protected by copyright. All rights reserved.