Plasmonic Au Nanoparticles Incorporated in the Zeolitic Imidazolate Framework (ZIF-67) for the Efficient Sunlight-Driven Photoreduction of CO2

Abstract

Nowadays, charge separation and efficient solar-light absorption are the main challenges in the photoreduction of CO₂. Although significant efforts have been made to overcome these issues, including the use of cocatalysts and doping, photocatalysts still suffer from low photocatalytic activity and stability. Herein, the localized surface plasmonic resonance (LSPR) effect of Au nanoparticles deposited into the zeolitic imidazolate framework (ZIF-67) was investigated for the photoreduction of CO₂. Different Au loadings in ZIF were prepared and their effects were studied on photocatalytic performance. Plasmonic Au nanoparticles (PNPs) in the size range of 30–40 nm improved visible-light absorption, enhanced charge separation, and played an important role in selectivity. A volcano relationship of plasmonic Au NPs with methanol and ethanol generation was found, along with the deposition of plasmonic Au nanoparticles. A total yield of 2.5 mmol g^–1 h^–1 of methanol and 0.5 mmol g^–1 h^–1 of ethanol were obtained, which are the highest values compared to those reported in other studies. Finally, our results revealed that Au PNPs have a significant impact on the selectivity and photocatalytic activity of ZIF-67 for the photoreduction of CO₂ and could be a promising alternative toward designing plasmonic reticular materials.