Influence of TIO2-rGO optical properties on the photocatalytic activity and efficiency to photodegrade an emerging pollutant

Abstract

TiO 2 -reduced graphene oxide (TiO 2 -rGO) photocatalysts with different mass ratios (GO:TiO 2 0.1-0.5-1%) were synthesized via a hydrothermal method and compared through their physico-chemical properties and photocatalytic activity in the degradation of an emerging contaminant, clofibric acid. The optical properties of the TiO 2 -rGO nanocomposites were first estimated in order to calculate the local volumetric rate of photon absorption inside a photocatalytic reactor. Radiation models were solved using the Monte Carlo method. The effect of rGO as well as the photocatalyst loadings on the radiation absorption was evaluated. The lowest photodegradation rate found in P25-rGO 1% was ascribed to an excess of rGO that could well favor charge carriers recombination leading to detrimental photoactivity. A GO/TiO 2 mass ratio of 0.5 % provided the fastest initial photodegradation rate under the operating conditions studied here. Finally, the photo-efficiency of all these photocatalysts was also analyzed by calculating the quantum efficiency parameter. The highest value of quantum efficiency was achieved with P25-rGO 0.5% at 100 mg L -1 , with an increase of 11% compared to the value obtained for P25-rGO 0%.

One-Pot Synthesis of TiO2-rGO Photocatalysts for the Degradation of Groundwater Pollutants

“…This can be attributed to the presence of GO, which subtracts some electrons from the semiconductor surface and reduces the radiative recombination phenomena [37]. As reported, it is possible to estimate the reduction degree of GO from the relative intensity between the GO and rGO containing samples [38]. The TiO 2 -GO sample exhibits bands with higher intensity, compared to the TiO 2 -rGO based composites.…”

“…reported, it is possible to estimate the reduction degree of GO from the relative intensity between the GO and rGO containing samples [38]. The TiO2-GO sample exhibits bands with higher intensity, compared to the TiO2-rGO based composites.…”

Integration of heterogeneous photocatalysis and persulfate based oxidation using TiO2-reduced graphene oxide for water decontamination and disinfection

“…Among various AOPs, heterogeneous photocatalysis using graphene based semiconductor metal oxides, mainly TiO 2 , and sulfate radical based AOPs (SR-AOPs) have attracted a lot of attention in recent years due to their widespread applicability and enhanced efficiency in degrading pollutants from water. TiO 2 is an established photocatalyst for wastewater detoxification [ 1 ]. However, its photocatalytic efficiency is still limited by the high rate of electron-hole pair recombination.…”

Indium Tin-Oxide Wrapped 3D rGO and TiO2 Composites: Development, Characterization, and Enhancing Photocatalytic Activity for Methylene Blue

“…Reduced graphene oxide (rGO) modified with carboxylic acids, hydroxyl groups, and epoxy groups has obvious advantages such as sensitivity to chemical doping, species adsorbed or bound, and structural deformation [17]. Nowadays, many researchers have been devoted to preparation of rGO doping TiO 2 photocatalysts for improving TiO 2 catalyst performance [18,19]. However, there is a clear disadvantage that the intermolecular force between rGO and TiO 2 is relatively weak and the way they combine via physisorption or van der Waals forces.…”