Magnetically retrievable Fe3O4@SiO2@ZnO piezo-photocatalyst: Synthesis and multiple catalytic properties

The piezo-/photocatalytic effects of ZnO have been in the limelight because of their great potential in environmental remediation and energy conversion. However, the poor recyclability of the suspended cat-alysts can cause inevitable secondary pollution, which is one of the major issues that limit the practical application of these materials. To address this problem, a magnetically retrievable Fe3O4@SiO2@ZnO nanocomposite was designed and successfully synthesized by multi-step reactions. The ZnO nanorods were vertically grown on the surface of the magnetic Fe3O4@SiO2 microspheres, while SiO2 served as an insulator to protect the inner core and to inhibit charge transfer across the core/shell interface. The Fe3O4@SiO2@ZnO nanocomposite can be easily collected and separated by using a magnetic field. Along with the good recyclability, the material also exhibited high efficiencies in piezocatalytic, photocat-alytic and piezo-photocatalytic dye degradation processes. The rate constant of piezo-photocatalysis reached 95.9 x 10-3 min-1, which was 2.2 and 6.1 times that of the individual piezocatalysis and photo -catalysis, respectively. The present result confirmed the existence of a synergetic effect between piezo-and photocatalytic processes. Hereby, we demonstrated that incorporation of a magnetic carrier is a fea-sible strategy to achieve retrievable and highly efficient piezo-/photocatalyst.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

In this study, a magnetically retrievable Fe3O4@SiO2@ZnO nanocomposite was successfully synthesized, which consisted of vertically grown ZnO nanorods on the surface of magnetic Fe3O4@SiO2 microspheres. SiO2 served as an insulator to protect the core and inhibit charge transfer. The nanocomposite showed high efficiencies in piezocatalytic, photocatalytic, and piezo-photocatalytic dye degradation processes, with a rate constant of piezo-photocatalysis reaching 95.9 x 10-3 min-1.