Metal-free polymer photocatalyst has emerged as a new generation of heterogeneous photocatalyst, featuring versatile photophysical and electronic properties by the structural design in a molecular level. The diverse combination of organic semiconductors in π-conjugated polymeric chain allows fine control in light absorbance and optical band gap to optimize energy transfer and thereby enhance photocatalytic efficiency. In the virtue of designability, polymer photocatalysts can be endowed with morphological and chemical traits for target-specific reactions.
1. W. Huang, J. Byun, I. Rörich, C. Ramanan, P. W. M. Blom, H. Lu, D. Wang, L. Caire da Silva, R. Li, L. Wang, K. Landfester, K. A. I. Zhang, Asymmetric Covalent Triazine Framework for Enhanced Visible Light Photoredox Catalysis via Energy Transfer Cascade, Angew. Chem. Int. Ed. 2018, 57,8316 –8320. Link
2. J. Byun, W. Huang, D. Wang, R. Li, K.A.I. Zhang, CO2‐Triggered Switchable Hydrophilicity of a Heterogeneous Conjugated Polymer Photocatalyst for Enhanced Catalytic Activity in Water, Angew. Chem. Int. Ed., 2018, 57, 2967-2971. Link
3. Z. J. Wang, S. Ghasimi, K. Landfester, K. A. I. Zhang, Molecular structural design of conjugated microporous poly(benzooxadiazole) networks for enhanced photocatalytic activity with visible light, Adv. Mater. 2015, 27, 6265-6270. Link
We design pure organic or hybrid porous materials for a wide range of applications. By controlling porosity and morphology, integrating various functional groups or immobilizing hybrid components on the porous materials, defined active centers, expended surface area, and enhanced absorption or selective permeation of substrates can be achieved for the aimed applications in catalysis or energy-relevant fields.
1. Wang, Z. J.; Ghasimi, S.; Landfester, K.; Zhang, K. A. I., Highly porous conjugated polymers for selective oxidation of organic sulfides under visible light, Chem. Commun. 2014, 50, 8177-8180. Link
2. Huang, W.; Wang, Z. J.; Ma, B. C.; Ghasimi, S.; Gehrig, D.; Laquai, F.; Landfester, K.; Zhang, K. A. I., Hollow Nanoporous Covalent Triazine Frameworks via Acid Vapor-Assisted Solid Phase Synthesis for Enhanced Visible Light Photoactivity, J. Mater. Chem. A 2016, 4, 7555. Link
Novel Reaction Discovery
The development of green and mild reaction conditions for known or new transformations is still challenging for organic chemists. Our group focuses its research on the discovery of organic reactions that are operationally simple, green and selective. Current research efforts are upon: (i) the development of new materials with suitable photoredox potentials, (ii) the application of those materials to high-valuable compounds synthesis with the scaling-up possibility. And (iii) the understanding of the reaction mechanisms in order to increase its efficiency, the scope and the general applicability of those new transformations.
1. Ghasimi, S., et al., A Conjugated Microporous Polymer for Palladium‐Free, Visible Light‐Promoted Photocatalytic Stille‐Type Coupling Reactions, Adv. Sci. 2017, 4, 1700101. Link
2. Huang, W., et al., A fixed-bed photoreactor using conjugated nanoporous polymer-coated glass fibers for visible light-promoted continuous photoredox reactions, J. Mater. Chem. A 2017, 5, 3792-3793. Link
3. Wang, L.; Huang, W.; Li, R.; Gehrig, D.; Blom, P. W. M.; Landfester, K.; Zhang, K. A. I., Structural Design Principle of Small-Molecule Organic Semiconductors for Metal-Free, Visible-Light-Promoted Photocatalysis. Angew. Chem. Int. Ed. 2016, 55, 9783-9787. Link
The applications of our materials are versatile. We mainly aim for the utilization of the designed polymer materials in fields in chemical synthesis as fine chemistry, energy applications as artificial photosynthesis and CO2 conversion or fixation, environmental science as metal-free and phpotocatalytic water treatment, and combination of photochemistry with biology as synthetic biological processes.
1. Wang, Z. J.; Garth, K.; Ghasimi, S.; Landfester, K.; Zhang, K. A. I., Conjugated Microporous Poly(Benzochalcogenadiazole)s for Photocatalytic Oxidative Coupling of Amines under Visible Light, ChemSusChem 2015, 8 (20), 3459-3464. Link
2. Li, R.; Byun, J.; Huang, W.; Ayed, C.; Wang, L.; Zhang, K. A. I., Poly-benzothiadiazoles and their derivatives as heterogeneous photocatalysts for visible light-driven chemical transformations, ACS Catal. 2018, 8, 4735-4750. Link
3. Li, R.; Ma, B. C.; Huang, W.; Wang, L.; Wang, D.; Lu, H.; Landfester, K.; Zhang, K. A. I., Photocatalytic Regioselective and Stereoselective [2 + 2] Cycloaddition of Styrene Derivatives Using a Heterogeneous Organic Photocatalyst, ACS Catal. 2017, 7 (5), 3097-3101. Link