SnFe2O4 mediated near-infrared-driven photocatalysis, photothermal sterilization and piezocatalysis

To make the most of solar energy, it is of great significance to utilize the near infrared (NIR) light outside the visible and UV region for the related applications. In this work, a multifunctional SnFe2O4 had been designed for this purpose. The SnFe2O4 was a full-solar-range responsive photocatalyst, which could realize the photocatalytic degradation of methylene blue under both visible and near infrared irradiation. Meanwhile, NIR triggered photothermal effect of SnFe2O4 favored sterilization and improved comprehensive purification of sewage. On the basis of unique piezoelectric property, SnFe2O4 also presented the excellent piezocatalytic activity and further a synergistic effect of piezocatalysis enhanced NIR-driven photocatalysis was realized. Finally, the possible mechanism was investigated by radical scavenging tests, ESR signals and density functional theory calculation. The simulated electronic structure and molecular activation well explained the generation of reactive oxygen species and it was also well supported by experimental results. This work provided a theoretical basis for extending use of solar spectrum for the photocatalysis and constructing the multifunctional photocatalysis and piezocatalysis.