Efficient degradation of MB dye by 1D FeWO4 nanomaterials through the synergistic effect of piezo-Fenton catalysis

Ferrous tungstate (FeWO4) nanoparticles, nanorods, and nanofibers are prepared by hydrothermal method and their piezo-Fenton synergistic catalysis is investigated. The as-prepared one-dimensional FeWO4 nanofibers show super high catalytic efficiency on the degradation of methylene blue (MB) and Rhodamine B (RhB). Furthermore, the catalytic reaction takes place under neutral conditions without the adjustment of pH. Under ultrasonic vibration with trace H2O2 (0.02 vol%), FeWO4 nanofibers can remove up to 99.5% of MB (20 mg/L) in 14 min. Recyclability experiments demonstrate that FeWO4 nanofibers retain their catalytic activity after four recycles. The active species capturing experiments found that h(+) is the dominant active species in the degradation process. The high catalytic efficiency of FeWO4 nanofibers ascribes to the synergistic effect of piezocatalytic and Fenton catalytic, which facilitates the transfer of charge carriers and accelerates the piezocatalytic process. The piezo-induced e(-) could favor the Fe3+/Fe2+ cycle and accelerated the Fenton catalytic process. This work presents a new design strategy of advanced oxidation processes for remediation of water pollution, which is of great significance to environmental protection.