Ce-doped perovskite-type catalyst derived from Ti-bearing blast furnace slag for photocatalytic removal of gaseous toluene under visible light

Since the yield of titanium-bearing blast furnace slag (TF) during the smelting of vanadium titanium magnetite is large, it is urgent to find ways to recycle it and implement its value-added utilization. In this study, a perovskiterich photocatalyst was prepared by acid-washing of TF, and then Ce was doped to modify it for photocatalytic removal of gaseous toluene under the irradiation of visible light. XRD, XRF and XPS analyses demonstrated that the perovskite phase was enriched after the acid-washing, and the content of CaTiO3 in the acid-washed slag (AS) also increased after Ce doping. The combined N2 adsorption-desorption, UV-Vis DRS, EIS, PL, and ESR analysis results indicated that the photocatalytic performance of the mentioned photocatalyst was related to the Ce dopant content. The AS doped with 20% Ce (20% Ce-AS) had a lower band gap and larger specific surface area than the others catalysts. Under visible light radiation, more active radicals were produced, and the removal efficiency of toluene reached 92.08% for 20% Ce-AS. In addition, the results of the in situ DRIFTS tests indicated that toluene was gradually degraded by the Ce-doped perovskite-type photocatalyst to alcohols and aldehydes and mineralized to H2O and CO2. This study is expected to provide a new approach for the technical development of the value-added utilization of TF coupled with the efficient removal of toluene.