TiO2/graphene oxide nanocomposite with enhanced photocatalytic capacity for degradation of 2,4-dichlorophenoxyacetic acid herbicide

Abstract

The present study investigates the photocatalytic degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D), a hazardous herbicide using TiO₂/Graphene oxide nanocomposite photocatalysts. The nanocomposite photocatalysts were synthesized via solvothermal method by varying the weight percentage of graphene oxide. The nanocomposite photocatalysts were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer Emmet Teller (BET) adsorption isotherm, Fourier-transform infrared (FT-IR) and UV–visible-diffuse reflectance spectroscopy (UV–Vis-DRS) analysis. The XRD pattern of nanocomposite was found unaltered, whereas a significant change around 33–91% was observed in the surface area of nanocomposites as compared to the pristine TiO₂. The UV–Vis DRS study showed a blue shift in the band edge of the composites around 21–29 nm. The complete photocatalytic degradation of 2,4-D was achieved using TiO₂/GO_7% catalyst within 4 h of reaction under UV-light irradiation. The photocatalytic activity of the synthesized nanocomposite photocatalysts was also compared with the standard Degussa P-25 TiO₂ photocatalyst. The order of photocatalytic activity of the synthesized photocatalysts were TiO₂/GO_7% > P25-TiO₂ > TiO₂/GO_5% > TiO₂/GO_2% > TiO₂/GO_1% > TiO₂/GO_10% > TiO₂/GO_0.5% > Pristine-TiO₂. This study offers a better platform for the synthesis of new composite photocatalytic materials for environment abatement by the degradation of organic pollutants.