A Parametric Study of the Crystal Phases on Au/TiO<sub>2</sub> Photocatalysts for CO<sub>2</sub> Gas-Phase Reduction in the Presence of Water
oleh: Clément Marchal, Caroline Mary, Leila Hammoud, Qingyang Xi, Joumana Toufaily, Tayssir Hamieh, Luka Suhadolnik, Paolo Fornasiero, Christophe Colbeau-Justin, Valérie Caps, Thomas Cottineau, Valérie Keller
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2022-12-01 |
Deskripsi
Au/TiO<sub>2</sub> photocatalysts were studied, characterized, and compared for CO<sub>2</sub> photocatalytic gas-phase reduction. The impact of the nature of the TiO<sub>2</sub> support was studied. It was shown that the surface area/porosity/TiO<sub>2</sub> crystal phase/density of specific exposed facets and oxygen vacancies were the key factors determining CH<sub>4</sub> productivity under solar-light activation. A 0.84 wt.% Au/TiO<sub>2</sub> SG (Sol Gel) calcined at 400 °C exhibited the best performance, leading to a continuous mean CH<sub>4</sub> production rate of 50 μmol.h<sup>−1</sup>.g<sup>−1</sup> over 5 h, associated with an electronic selectivity of 85%. This high activity was mainly attributed to the large surface area and accessible microporous volume, high density of exposed TiO<sub>2</sub> (101) anatase facets, and oxygen vacancies acting as reactive defects sites for CO<sub>2</sub> adsorption/activation/dissociation and charge carrier transport.