Highly Efficient Photodegradation of RHB-MO-MB Mixture Dye Wastewater by WO₃/Fe₃O₄/Diatomite under Different Condition

Abstract

Composite photocatalyst WO3/Fe3O4/Diatomite was prepared by solvent thermal method for the removal of composite dyes from wastewater. The structure and properties were characterized by a series of test methods, etc. In the presence of Fe3O4, the WO3 is enhanced in the direction of (101) and (200) and loaded on the surface of diatomite (DT). The results of UV-vis analysis implies that the Fe3O4 and diatomite are beneficial to efficiency. The hysteresis loop shows that the WO3/Fe3O4/DT composites can be recycled by a magnet, indicating that the composites possess magnetic and recyclable. The WO3/Fe3O4/DT composites have a good photocatalytic effect in both acidic and alkaline conditions for RHB-MO-MB mixture dye and has broad application prospects. The results of free radical analysis indicated that •O2- and •OH were the main active species. The mechanism of photocatalytic removal of dyes is described based on radical trapping experiments and energy band structure analysis. It is shown by three photocatalytic cycle experiments that the morphology of the WO3/Fe3O4/DT composites remains unchanged, and the photocatalytic activity is maintained. This work provides a new idea for the synthesis of photocatalysts and wastewater treatment.