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 CO 2 . 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 CO 2 . 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 CO 2 and could be a promising alternative toward designing plasmonic reticular materials.

Plasmonic Materials: Opportunities and Challenges on Reticular Chemistry for Photocatalytic Applications

“…Over the last decades, classic semiconductor materials have shown promising results like TiO 2 , g‐C 3 N 4, and graphene [50–52] . Moreover, ambient conditions (e. g., ambient temperature and atmospheric pressure) during the CO 2 redox reactions can also obtain high yields comparable with other scalable industrial processes [13,53] . Their economic cost and overall yield can put them as a considerable alternative for industrial purposes.…”

“…However, efficient interaction between Au plasmonic nanoparticles (PNPs) and PPF‐3_1 surface is crucial in order to enable the hot electron injection. The use of several surfactants like polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB) among others is common to achieve this interaction [22,53] . This provides a protective barrier to avoid agglomeration and catalytic decays referred to deactivation of active sites.…”

“…Recently, Becerra and coworkers made a study using a ZIF‐67 incorporated with plasmonic nanospheres for CO 2 photoreduction [53] . Similar to ZIF‐8, this MOF has properties for proper CO 2 photoreduction.…”

Photocatalytic and Electrocatalytic Properties of Cu-Loaded ZIF-67-Derivatized Bean Sprout-Like Co-TiO2/Ti Nanostructures

“…Metal–organic frameworks (MOFs) including other materials have been extensively employed in diverse application areas such as environments, adsorbents, organic light emitting displays, sensors and catalysts [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Among diverse MOFs, the zeolitic imidazolate framework (ZIF) exhibits zeolite-like topologies where imidazolate linkers are connected with tetrahedrally coordinated transition metal ions such as Co and Zn [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. In this ZIF-class, ZIF-67 has Co-N tetrahedral coordination commonly synthesized with Co(II) precursor and 2-methylimidazole [ 5 , 6 , 7 , 8 , 9 , 10 ].…”

“…The developed catalyst showed high light absorption and charge transfer efficiency for higher photocatalytic performance. For an application area of CO 2 reduction [ 25 , 26 , 27 ], CdS/ZIF-67 nanocomposites were synthesized by a simple wet reaction method and tested for photocatalytic CO 2 reduction reaction under a 300 W Xe lamp (with 420 nm cut-off filter) [ 23 ]. The catalysts showed CO and H 2 as the main products, with 184 μmol g −1 ·h −1 and 1098 μmol g −1 h −1 , respectively, and a CO selectivity of 5–45%.…”