Enhanced piezo-catalytic H2O2 production over Bi0.5Na0.5TiO3 via piezoelectricity enhancement and surface engineering

The piezo-catalytic hydrogen peroxide (H2O2) production is a promising alternative to traditional anthraquinone oxidation process, but it remains a challenging task. The low conversion efficiency of mechanical energy and the limitedsurface-active sites are the challengings for improving reaction efficiency. Moreover, piezo-catalysts are difficult to prepare in large quantities, limiting the industrial application. To address this issue, this study utilized piezoelectricity enhancement and surface engineering to regulate the Bi0.5Na0.5TiO3 (BNT) for piezo-catalytic H2O2 production. We successfully synthesized an efficient and stable piezo-catalyst, Ag-loaded Bi0.5Na0.5TiO3-AgNbO3 solid solution (Ag/BNT-AN), that was applied to two-channel H2O2 production. The piezo-catalytic activity of Ag/BNT-AN piezo-catalyst was greatly improved through joint regulation of enhancing piezoelectricity by Ag and Nb co-substitution, as well as promoting O2 reduction and H2O oxidation reactions by surface modification with Ag nanoparticals and hydroxyl groups. The optimal Ag/BNT-AN piezo-catalyst displayed H2O2 production rates of 469 µmol g−1 h−1 under ultrasonic vibration, which was 13 times higher than pure BNT. Additionally, the study found that H2O2 could also be synthesized when the catalyst was subjected to simple stirring as mechanical stress, indicating the potential of Ag/BNT-AN to harness low-frequency mechanical energy. This work provides an effective strategy for regulating piezo-catalysts and presents a catalyst design paradigm at the kilogram level.