Photocatalytic reduction of CO2 to hydrocarbons by using photodeposited Pt nanoparticles on carbon-doped titania

Abstract

Photocatalytic reduction of CO2 with H2O was performed in a top-irradiation stainless-steel photoreactor with Pt/C-TiO2 as the photocatalyst. Pt/C-TiO2 photocatalysts with different amount of Pt (0.5–3.0 wt.%) were synthesized by the photodeposition method and were characterized in detail by X-ray powder diffraction (XRD), nitrogen physisorption measurement (BET), UV–vis diffuse reflectance spectroscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoelectrochemical measurements. Results revealed the photocatalytic reduction of CO2 increased by loading Pt on the surface of C-TiO2. The main reaction product was methane (CH4), however, hydrogen (H2) and carbon monoxide (CO) were also detected. The highest yields of CH4, H2, and CO were achieved in the presence Pt/C-TiO2 with a nominal loading of 0.88 wt.%, resulting from the efficient interfacial transfer of photogenerated electrons from C-TiO2 to Pt as it is evidenced from photoelectochemical measurements.