Germanium-substituted Zn2TiO4 solid solution photocatalyst for conversion of CO2 into fuels
| Autor: | Jiaxue Lu, Jinni Shen, Deli Li, Jun Liang, Yao Chai, Yongfan Zhang, Xuxu Wang, Li Li |
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| Rok vydání: | 2019 |
| Předmět: |
Valence (chemistry)
010405 organic chemistry Band gap Chemistry Spinel chemistry.chemical_element Germanium engineering.material 010402 general chemistry 01 natural sciences Catalysis 0104 chemical sciences Artificial photosynthesis Effective mass (solid-state physics) Chemical engineering Photocatalysis engineering Physical and Theoretical Chemistry Solid solution |
| Zdroj: | Journal of Catalysis. 371:144-152 |
| ISSN: | 0021-9517 |
| DOI: | 10.1016/j.jcat.2019.01.017 |
| Popis: | Photocatalytic CO2 reduction conjugated with H2O oxidation is regarded as a promising artificial photosynthesis system because it can simultaneously solve energy and environment problems. Here, a novel solid solution, Zn2Ti1−xGexO4 (0 ≤ x ≤ 0.15), with high photocatalytic activity for the reaction was successfully synthesized via a facile molten salts route. The Zn-based solid solutions with size about 200 nm have a homogeneous inverted cubic spinel structure (Fd3m) and a continuously modulated band gap with the Ge content. For the CO2 reduction reaction with H2O under simulated solar irradiation, the Zn2Ti1−xGexO4 solid solutions display not only high activity for the conversion of CO2 into CH 4 and CO fuels, but also long-term stability (>60 h of catalytic reaction). Experimental results and theoretical calculations indicated that the conduction and the valence bands of the cubic spinel Zn2TiO4 are positively shifted by introducing Zn2GeO4 with a pseudocubic inverse spinel structure, but the band gaps of solid solutions are simultaneously modulated with the introduction of germanium. Nevertheless, the Zn2TiO4 affords a light-carrier effective mass and strong electron delocalization by forming a solid solution with Zn2GeO4, which is beneficial to improving migration of photogenerated electrons and holes. As a synergistic result of band gap narrowing and high carrier diffusion, good conversion efficiencies for production of solar fuels through the reactions of CO2 reduction with H2O are achieved. |
| Databáze: | OpenAIRE |
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