Rational fabrication of needle with spherical shape ternary reduced Graphene Oxide-HoVO_4-TiO_2 photocatalyst for degradation of ibuprofen under visible light

摘要

The photocatalytic decomposition is a highly efficient method for removing environmental pollution. Reduced graphene oxide (rGO) loaded HoVO4-TiO2 was prepared hydrothermally and characterized by XRD, FE-SEM, EDX, TEM, XPS, FT-Raman spectral analysis, FT-IR and UV-DRS. The powder XRD confirmed the formation of the anatase structure of the TiO2 and monoclinic scheelite structure of HoVO4. FE-SEM images of rGO-HoVO4-TiO2 depicted a mixed needle and spherical structure. DRS spectra of rGO and HoVO4 in rGO-HoVO4-TiO2 composite increased its visible absorbance region. The photocatalytic study revealed an enhanced photodecomposition efficiency of rGO-HoVO4-TiO2 composite material than HoVO4, TiO2, rGO-HoVO4, rGO-TiO2 at pH 7 in the removal of ibuprofen. The effects of operational parameters such as the catalyst amount, ibuprofen concentration have been analyzed and compared with the previous reports. The degradation mechanism is proposed for ibuprofen under visible light illumination. Moreover, the rGO-HoVO4-TiO2 catalyst has excellent stability and the photocatalytic decomposition of ibuprofen mainly depends on superoxide radicals photogenerated from rGO-HoVO4-TiO2 under visible light illumination. The antibacterial activity was investigated against Staphylococcus aureus, staphylococcus pyogenes, Bacillus subtilis, and Escherichia coli and the catalyst has good to moderate activity.