Enhanced Photocatalytic Methylene Blue Degradation and Chromium(VI) Photoreduction under Sunlight by Fe3O4@rGO@CeO2/Nd2O3 as Magnetic Recyclable Photocatalyst

Abstract

A significant global concern is in the easy separation, recyclability and reusability of photocatalysts in industrial wastewater treatment applications. Therefore, in this study, the synthesis of magnetically separatable Fe3O4@rGO@CeO2/Nd2O3 photocatalyst using a one-step solvothermal method is reported, which overcomes all these challenges. A binary lanthanide oxides CeO2/Nd2O3 anchored on rGO-wrapped Fe3O4 core-shell magnetic nanoparticles. The synthesized magnetic photocatalyst nanocomposite has been characterized using XRD, FESEM, EDX, HRTEM, TGA-DTA-DSC, VSM, FTIR and UV-visible spectrophotometer. In this work, the Fe3O4 synthesized by solvothermal technique achieved the highest saturation magnetization (MS), 101.84 emu/g. The results showed that Fe3O4@rGO@CeO2/Nd2O3 photocatalyst had more excellent stability up to 880 ºC confirmed by TGA-DTA-DSC analysis and efficient potential for the degradation of methylene blue by photo-Fenton reaction and reduction of Cr(VI) in formic acid under sunlight. The prepared photocatalyst efficiently degrades 98% of methylene blue in 50 min at neutral pH and quick photoreduction of Cr(VI) of 99% takes place within 40 min. After six cycles, the repeatability of the photocatalytic activity exhibited just a slight reduction in catalytic efficiency for degradation of methylene blue and photoreduction of Cr(VI).