Photocatalytic hydrogenation and reduction of CO 2 over CuO/ TiO 2 photocatalysts
Journal
Applied Surface Science
Journal Volume
454
Pages
313-318
Date Issued
2018
Author(s)
Abstract
Photocatalytic hydrogenation of carbon dioxide is one of the promising technologies which can convert carbon dioxide under ambient condition to sustainable fuels, such as methane and methanol. The pure TiO 2 and copper doped TiO 2 photocatalysts with 1, 3 and 5 wt.% CuO were prepared by sol-gel processing within reverse micelles and characterized by N 2 physisorption, UV¡VVis, XRD, TPR, Raman spectroscopy, photoelectrochemical measurement and analysis of work function. Two types of experimental photocatalytic hydrogenation and reduction of CO 2 in the liquid phase and gas phase, respectively, were carried out under hydrogen. In the case of reaction in liquid phase, the highest yield of CH 4 was found in the presence 5 wt.% CuO/TiO 2 and pure TiO 2 . Activity of photocatalysts was affected mainly by two factors: the availability of active sites (S BET ) and the work needed to move the electron from surface (work function). In gas reaction, the most CH 4 and CO were generated in order: TiO 2 > 3 wt.% CuO/TiO 2 > 5 wt.% CuO/TiO 2 > 1 wt.% CuO/TiO 2 . In the gas phase, the enhanced photocatalytic performance was connected with better separation of the generated charge carriers. ? 2018 Elsevier B.V.
Subjects
CO 2
CuO/TiO 2
Photocatalysis
Photocurrent
Work function
Type
journal article