Photocatalytic reduction of CO2 using Pt/C3N4 photocatalyts

Abstract

C3N4 is an abundant carbon based, conjugated polymer with an attractive electronic band structure and increased physicochemical stability. As far as photocatalytic CO2 reduction is concerned, the adsorption of CO2 on the surface of C3N4 based photocatalyst is the first step of the reaction mechanism. In case of the combination of C3N4 with metal complexes such as those of Pt, C3N4 acts as a visible light harvesting system and catalyst whereas Pt complex provides the CO2 active sites. The complex method of the photocatalytic reduction of CO2 emissions in the presence of photocatalyst can be done using previously published methods The pristine C3N4 (gC(3)N(4) and p-C3N4) and platinum doped C3N4 photocatalysts with 3 wt% of Pt were prepared by two different ways and investigated for the photocatalytic reduction of CO2. The main detected reaction products were methane, hydrogen and carbon monoxide. The physico-chemical properties of photocatalysts were characterized in detail by low-temperature nitrogen physisorption, X-ray powder diffraction and diffuse reflectance UV-Vis spectroscopy. The highest yields of CH4, H-2 and CO were achieved in presence of 3 wt% Pt/p-C3N4. The correlation between textural, optical and photoelectrochemical properties and the photocatalysts activity was a subject of this research.