Session:

The conversion of CO₂ into chemical fuels via photoreduction is regarded as one of the most effective methods of addressing the environmental greenhouse gas problem and the energy shortage. Creation of a suitable active and selective photocatalyst is the main goal of photocatalysis research. Meanwhile, better catalytic efficiency and controlled selective production yield can be achieved by developing photocatalysts, which can be facilitated by a deeper understanding of the chemical pathways. In this context, investigation of the reaction mechanism and understanding the nature of the active sites have recently attracted more attention. Thus, it is important, while challenging, to monitor reaction intermediates during the gas-phase photocatalytic CO₂ reduction reaction to achieve higher CO₂ conversion yield. In this perspective, we report a mechanistic insight for the photocatalytic CO₂ reduction over Two-dimensional ZnIn₂S₄ as an active model photocatalyst that exhibits promising photocatalytic performance with a high absorption coefficient under visible light. Our study combines in-situ FTIR investigation, physisorption measurements, operando XAS. We systematically probed the intermediate species (HCOO*, and CH₃O*) and established a co-feeding scheme to confirm the reaction pathway. The change in the oxidation state and the charge transfer behaviors were monitored for Zn, In, and S during the reaction coordinate to explore the active sites towards CO₂ molecules adsorption and activation. Finally, DFT calculations will be presented to prove the validity of the reaction mechanism.

Co-Author(s): Kuei-Hsien Chen (Academia Sinica), Li-chyong Chen (National Taiwan University)

Amr Sabbah

Appearances