Solar energy conversion and storage into a high density energy medium e.g H2 via water splitting has been attracting substantial interest over the last decade, which can provide not only renewable H2 fuel but also a carbon-zero economy. The key in this technology is an efficient photocatalyst. The current low efficiency in water splitting to H2 fuel process is contributed to both fast charge recombination and large bandgap of an inorganic semiconductor.1
Stimulated by our recent research outcomes on the charge dynamics in inorganic semiconductor photocatalysts, we developed novel materials strategies for solar driven hydrogen synthesis by polymer photocatalysts. One is to mitigate the charge recombination by improving the degree of polymerization of a polymer e.g. C3N4. With respect to it, one successful example of pure water splitting in a suspensions solution under visible light has been demonstrated for the first time.2,3 The other strategy is to narrow the bandgap of carbon nitrides by bandgap engineering. The material prepared via an oxygen rich organic precursor has a dark color, resulting into an efficient H2 production from water by UV and visible, even IR light with a quantum yield (QY) of 10% at 420 nm, which is the first example of a polymer photocatalyst working in such long wavelength for H2 fuel production.4 The charge dynamics in these polymer photocatalysts were also systematically investigated,5 resulting into a photoanode composed this low cost polymer for solar to H2 fuel synthesis.6 In parallel, new polymers for water oxidation, which is harder and more challenging than half H2 production reaction, has been discovered, leading to a covalent triazine framework polymer with efficient activity for oxygen production from water apart from H2 production.7
1. Y. Wang, H. Suzuki, J. Xie, O. Tomita, D. J. Martin, M. Higashi, D. Kong, R. Abe, J. Tang, Chem. Rev., 2018, DOI: 10.1021/acs.chemrev.7b00286
2. D. J. Martin, P.J.T. Reardon, S.J.A Moniz, J. Tang. J. Am. Chem. Soc., 2014, 136, 12568-12571.
3. D. J. Martin, K. Qiu, S.A. Shevlin, A.D. Handoko, X. Chen, Z. Guo, and J. Tang. Angewandte Chemie International Edition 2014, 53, 9240-9245.
4. Y. Wang, M.K. Bayazit, S.J Moniz, Q. Ruan, C. Lau, N. Martsinovich, J. Tang, Energy Environ Sci, 2017, 10, 1643-1651.
5. R. Godin, Y. Wang, M. A. Zwijnenburg, J. Tang, J. R. Durrant, J. Am. Chem. Soc. 2017, 139 (14), 5216–5224
6. Q., Ruan, W. Luo,, J. Xie,, Y. Wang,, X. Liu,, Z. Bai,, CJ. Carmalt, J. Tang, Angewandte Chemie International Edition, 2017, 28, 8221-8225.
7. J. Xie, S. A Shevlin, Q. Ruan, S. Moniz, Y. Liu, X. Liu, Y. Li, C. C. Lau, Z. X. Guo, J. Tang, Energy Environ Sci, 2018, DOI: 10.1039/C7EE02981K
Prof. Junwang Tang is a Professor of Chemistry and Materials Engineering in the Department at UCL, Director of the University Materials Hub and a Fellow of the RSC. He received his PhD in Physical Chemistry in 2001. His research interests encompass solar H2 synthesis from water, CO2 capture and conversion, photocatalytic methane conversion and ammonia synthesis as well as functional materials synthesis by a microwave intensified fluidic system. Such studies are undertaken in parallel with the mechanistic understanding and device optimisation to address the renewable energy supply and environmental purification. His research has led to >120 papers with >8000 citations, 11 patents and many invited lectures. He is the Editor-in-Chief of the Journal of Advanced Chemical Engineering, an Associate Editor of Asia-Pacific Journal of Chemical Engineering, the guest Editor-in-Chief of the International Journal of Photoenergy and Associate Editor of Chin J. Catalysis apart from sitting on the editorial board of other international journals.