Ionic Porous Aromatic Framework as a Self-Degraded Template for the Synthesis of a Magnetic γ-Fe2O3/WO3·0.5H2O Hybrid Nanostructure with Enhanced Photocatalytic Property

Abstract

An ionic porous aromatic framework is developed as a self-degraded template to synthesize the magnetic heterostructure of γ-Fe2O3/WO3·0.5H2O. The Fe3O4 polyhedron was obtained with the two-phase method first and then reacted with sodium tungstate to form the γ-Fe2O3/WO3·0.5H2O hybrid nanostructure. Under the induction effect of the ionic porous network, the Fe3O4 phase transformed to the γ-Fe2O3 state and complexed with WO3·0.5H2O to form the n-n heterostructure with the n-type WO3·0.5H2O on the surface of n-type γ-Fe2O3. Based on a UV-Visible analysis, the magnetic photocatalyst was shown to have a suitable band gap for the catalytic degradation of organic pollutants. Under irradiation, the resulting γ-Fe2O3/WO3·0.5H2O sample exhibited a removal efficiency of 95% for RhB in 100 min. The charge transfer mechanism was also studied. After the degradation process, the dispersed powder can be easily separated from the suspension by applying an external magnetic field. The catalytic activity displayed no significant decrease after five recycles. The results present new insights for preparing a hybrid nanostructure photocatalyst and its potential application in harmful pollutant degradation.