Benzothiazole-Based Covalent Organic Frameworks with Different Symmetrical Combinations for Photocatalytic CO2 Conversion
journal contributionposted on 2021-10-01, 17:36 authored by Young Hyun Kim, Nayeong Kim, Jeong-Min Seo, Jong-Pil Jeon, Hyuk-Jun Noh, Do Hyung Kweon, Jungki Ryu, Jong-Beom Baek
The physical and photochemical properties of covalent organic frameworks (COFs) can be tuned by their structural features such as the chemical composition and conjugation of building units. The combination of building units with different intrinsic properties can also influence their intrinsic electronic, adsorption, and optical properties. For the study on the symmetrical feature of COF and its physical/photochemical properties, we prepared benzothiazole-based COFs (TTzTp and BTzTp) with two different combinations, composed of tris-benzothiazole triamine (TTz) or bis-benzothiazole diamine (BTz) with triformylphloroglucinol (Tp), respectively. For their C3+C3 and C3+C2 symmetries, the COFs, synthesized from benzothiazole core units with approximately twice the difference in their pore dimensions, showed good affinity with CO2 and light-harvesting properties depending on the conjugation state of building units. The COFs were then applied as photosensitizers in a photocatalytic CO2 conversion system. The larger-pore-sized BTzTp showed a higher CO2-to-CO conversion rate than TTzTp, which stemmed from enhanced photocatalytic driving force by suitable band alignment, wider band gap with longer separated charge lifetime, and higher charge carrier mobility with a higher crystalline fraction in the structure.
Read the peer-reviewed publication
wider band gaptwo different combinationstp ), respectivelysuitable band alignmentshowed good affinitycovalent organic frameworkshigher crystalline fractionharvesting properties dependingdifferent symmetrical combinations3 </ sub2 </ subsized btztp showeddifferent intrinsic propertiesbenzothiazole core unitsco conversion ratesymmetrical featurephotochemical propertiesoptical propertiesintrinsic electronichigher cobuilding unitsstructural featuresprepared benzothiazolephotocatalytic coconversion systemchemical compositionbenzothiazole triaminebenzothiazole diamineapproximately twicealso influence