Introduction of Fe on rGO/TiO2 improves styrene visible light-driven photocatalytic oxidation: Characterization, stability, kinetics, and mechanism

Abstract

Photocatalytic process is a preferable strategy for air pollutant removal due to its high efficiency and mild operating condition. In this study, co-doping of reduced graphene oxide (rGO) and Fe were performed on TiO2 to enhance styrene removal. Addition of 0.1 wt% rGO promoted the photocatalytic activity of TiO2 and further improvement was achieved by introduction of Fe. The best photocatalytic activity was achieved by 0.1 wt%rGO/Fe0.5%/TiO2 which might be carried out by changes in reduction of band gap and electron-hole pair recombination rate. This result was also proven by the characterization analyses along with the detection of OH radicals which played an important role in the photocatalytic degradation of styrene. 1 % relative humidity accelerated photocatalytic degradation of styrene due to supply of OH radical species, however, excess amount of water vapor led to declining of photocatalytic activity due to adsorption competition on active sites. Furthermore, kinetics study using Langmuir Hinshelwood kinetics model 4 performed the best fitting with experimental data and proposed photocatalytic reaction mechanism was also built from analysis of generated intermediates.