Photocatalytic degradation of toxic aquatic pollutants by novel magnetic 3D-TiO2@HPGA nanocomposite

In this study, a series of photocatalysts were prepared, namely bare 3D-TiO2 (b-3D-T), magnetic 3D-TiO2: (m3D-T) and magnetic 3D-TiO2@Hierarchical Porous Graphene Aerogels (HPGA) nanocomposite: (m3D-T-HPGA NC) by solvothermal process. The prepared photocatalysts were analyzed by using X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), Vibrating sample magnetometer (VSM), Brunauer-Emmett-Teller (BET) and Diffuse Reflectance Measurement - Ultraviolet (DRS-UV) to know their physical and chemical properties. The photocatalytic degradations of two toxic aquatic pollutants viz., Cr(VI) and bisphenol A (BPA) were tested by using the prepared photocatalysts. Parameters such as initial pollutant concentration, solution pH, photocatalyst dosage, wavelength and light intensity were investigated to optimize the process. The photocatalytic properties of prepared catalyst were analyzed based on the degradation of Cr(VI) and BPA under UV irradiation. The modified photocatalysts showed better performance as compared to b-3D-T photocatalyst. This better performance is ascribed to efficient charge transfer between b-3D-T nanoparticles to the porous graphene sheets. The maximum photocatalytic degradation of Cr(VI) was found to be 100% with m3D-T-HPGA NC within 140 min, whereas a removal efficacy of 100% and 57% was noticed in case of m3D-T and b-3D-T within 200 and 240 min, respectively. In the case of BPA, the maximum degradation efficiency was found to be 90% with m3D-T-HPGA NC within 240 min.