| Autor: |
Singh N; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea., Yadav D; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea., Mulay SV; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea., Kim JY; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea., Park NJ; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea., Baeg JO; Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), 100 Jang-dong, Yuseong, Daejeon 305 600, Republic of Korea. |
| Abstrakt: |
Solar light-driven fuel production from carbon dioxide using organic photocatalysts is a promising technique for sustainable energy sources. Band gap engineering in sustainable organic photocatalysts for improving efficiency and fulfilling the requirements is highly anticipated. Here, we present a new strategy to engineer the band gap in covalent organic framework (COF) photocatalysts by varying the push-pull electronic effect. To implement this strategy, we have designed and synthesized four different COFs using a tripodal amine 4,4',4″-(1,3,5-triazine-2,4,6-triyl)tris(([1,1'-biphenyl]-4-amine)) [Ttba] with 1,3,5-triformylbenzene ( COF-1 ), 2,4,6-triformylphloroglucinol ( COF-2 ), 2,4,6-triformylphenol ( COF-3 ), and 2,4,6-triformylresorcinol ( COF-4 ). On varying the number of hydroxyl units in the aldehyde precursor, the resulting COFs allow the fine-tuning of their band gap and band edge positions and result in different morphologies with varying surface areas. The enhanced optical properties of COF-3 and COF-4 with very suitable band gaps of 2.02 and 1.95 eV, respectively, enable them to demonstrate a high-efficiency photobiocatalytic system for NADH photoregeneration and enhanced visible light-driven formic acid production at a rate of 226.3 μmol g -1 in 90 min. The triazine core enables efficient charge separation, while the hydroxyl groups induce an electronic push-pull effect, regulating their photocatalytic efficiency. The results demonstrated the morphology-guided enhanced surface area and dual keto-enol tautomerism-induced push-pull effect in asymmetrical charge distribution as key features in the fine-tuning of the photocatalysts. |
