ABSTRACT
186In this work, graphene-TiO2 nanocomposites (G-TiO2) were synthesized by a sol-gel method using titanium isopropoxide as Ti-precursors and reduced graphene oxide (RGO) and used as photocatalyst for the decolorization of malachite green (MG). Graphene oxide (GO) was prepared by the modified Hummers-Offeman method in presence of ultrasonic irradiation. The prepared GO and graphene-TiO2 was characterized using TEM, XRD. Decolorization of MG has been achieved using hydrodynamic cavitation and in combination with other advanced oxidation processes. The hydrodynamic cavitation was first optimized in terms of different operating parameters such as operating inlet pressure, and pH of the operating medium to get the maximum degradation of MG. In the hybrid techniques, combination of hydrodynamic cavitation with H2O2, G-TiO2, and G-TiO2/H2O2 have been used to get the enhanced degradation efficiency through hydrodynamic cavitation device. The maximum extent of MG decolorization as 99.4% has been observed using hydrodynamic cavitation in conjunction with G-TiO2/ H2O2 under the optimized conditions at inlet pressure 2 bar and pH value 8.5 in 90 min. The MG decolorization has been analyzed using UV-visible spectrophotometer.
