A Novel Ag2O/Fe–TiO2 Photocatalyst for CO2 Conversion into Methane Under Visible Light

Abstract

Modified TiO2 based nanomaterials have attained significant interest because of their unique morphology and excellent optical and photocatalytic properties. In this research, a very novel and highly efficient Ag2O/Fe–TiO2 porous structure was developed by simple hydrothermal method. The structural and morphological properties of the photocatalysts were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface areas of the samples were measured by Brunauer–Emmett–Teller theory (BET). The chemical composition and optical properties were investigated using X-ray photoelectron spectroscopy (XPS) and UV–visible spectroscopy. The optical absorption measurements show a clear red-shift in absorption edge of Fe–TiO2 after loading of Ag2O (Ag2O/Fe–TiO2 composite). Moreover, Ag2O varying ratio (0–15 at.%) has also enhanced the efficiency of Ag2O/Fe–TiO2 photocatalyst for CO2 conversion into methane under visible light illumination (λ ≥ 420 nm). The optimum ratio of Ag2O loading which exhibited maximum performance is 10 at.%. Moreover, the 10%Ag2O/Fe–TiO2 composite synthesized at 180 °C hydrothermal temperature showed an excellent increase in photocatalytic activity than other composites synthesized at 150 and 210 °C. This excellent performance of photocatalyst can be attributed to the highly porous petal-like structure of composite. Therefore, it is expected that the present study will be a good addition in literature for designing highly active photocatalytic materials for reduction of CO2 into useful hydrocarbons.