报告题目：Efficient Photocatalysts for Water Splitting and CH₄ Activation

报 告 人：Prof. Junwang (John) Tang, FRSC

报告时间：2018年12月20日（周四）上午9:00

报告地点：16号楼214会议室

 欢迎广大师生前往参加！

化学与化工学院

2018年12月12日

报告简介

Both water splitting and in particular methane/shale gas activation are very important scientifically and industrially as they promise an efficient pathway for either energy storage (e.g H2 production via water splitting driven by renewable energy) or high value chemical production (e.g. methane conversion to alcohols), thus have been attracting substantial interest over the last decade. However activation of either water or CH₄ is energy intensive and kinetically very challenging so that methane conversion is regarded as the “holy grail” in the catalytically chemical process. Photocatalysis provides a cost efficient potential to activation of such small molecules, either water or methane, at very mild conditions, while to achieve the potential is a huge challenge.

  Stimulated by our recent research outcomes on the charge dynamics in inorganic semiconductor photocatalysis, which reveal that the low conversion efficiency is due to both fast charge recombination and large bandgap of an inorganic semiconductor (1,2), we developed novel material strategies for solar driven hydrogen synthesis from water and methane conversion to methanol. The former was achieved by polymer photocatalysts (3) and the latter by highly dispersed atomic level iron oxides anchored on TiO₂ (4).

In the polymer photocatalysis, we found out by improving the degree of polymerization of a polymer e.g. C3N4 the charge recombination was substantially mitigated (3). Furthermore, one example of pure water splitting in a suspensions solution under visible light has been demonstrated for the first time(5). The other strategy is to narrow the bandgap of carbon nitrides by bandgap engineering. The material prepared via an oxygen rich organic precursorhas 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 (6). The charge dynamics in these polymer photocatalysts were also systematically investigated (7), resulting into a photoanode composed this low cost polymer for solar to H2 fuel synthesis (8). In parallel, the new polymer shows a much better activity for water oxidation compared with C3N4. Similar results have also been achieved on another group of polymer photocatalysts CTF (9). 

On the other hand, a highly dispersed atomic level iron species were synthesised on TiO2 photocatalyst, which shows a very good activity for methane conversion, resulting into ~97% selectivity towards alcohols operated at ambient condition by a one step chemical process (4).  Such photocatalyst is also very stable, promising an attractive industrial process of shale gas/methane ice conversion.

1. Y. Wang, H. Suzuki, J. Xie, O. Tomita, D. J. Martin, M. Higashi, D. Kong, R. Abe, J. Tang. Chem. Rev., 2018, 118, 5201-5241.

2. J. Tang, J. R. Durrant and D. R Klug, J. Am. Chem. Soc., 2008, 130(42),13885-13891.

3. D. J. Martin, K. Qiu, S.A. Shevlin, A.D. Handoko, X. Chen, Z. Guo, and J. Tang. Angew. Chem.-Int. Edit., 2014, 53, 9240-9245.

4. J. Xie, R. Jin, A. Li, Y. Bi, G. Sankar, D.Ma, J. Tang. Nature Catalysis, 2018, 1, 889-896.

5. D. J. Martin, P.J.T. Reardon, S.J.A Moniz, J. Tang. J. Am. Chem. Soc., 2014, 136, 12568-12571.

   6. Y. Wang, M.K. Bayazit, S.J Moniz, Q. Ruan, C. Lau, N. Martsinovich, J. Tang.Energy Environ Sci.,2017,10, 1643-1651.

   7. R. Godin, Y. Wang, M. A. Zwijnenburg, J. Tang, J. R. Durrant. J. Am. Chem. Soc., 2017, 139 (14), 5216-5224.

   8.  Q., Ruan, W. Luo, J. Xie, Y. Wang, X. Liu, Z. Bai, CJ. Carmalt, J. Tang. Angew. Chem.-Int. Edit., 2017, 28, 8221-8225.

   9.  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.,2018,11(6), 1617-1624.

    

    

报告人简介

Prof. Junwang Tang

Prof. Junwang Tang is a Fellow of the Royal Society of Chemistry, Director of the UCL Materials Hub and Professor of Chemistry and Materials Engineering in the Department of Chemical Engineering at University College London. He received his PhD in Physical Chemistry in DICP in Dalian in 2001 and then took a position at NIMS, Japan as a JSPS fellow, a senior researcher at Imperial College before he joined UCL in 2009. His research interests encompass photocatalytic small molecular activation (eg. CH₄, N₂, H₂O and CO₂),  microwave catalysis and chemical manufacturing by 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 ~130 papers with ~10000 citations, and many invited lectures. He also received many awards and the latest one is the 2018 IPS Scientist Award in the 22nd IPS conference. He also sits on the editorial/advisory board of a few international journals, eg. Materials Today Advances, Sustainable Energy and Fuels, Journal of Advanced Chemical Engineering (Editor-in-Chief), Chin. J. Catal. (Associate Editor) and Asia-Pacific Journal of Chemical Engineering (Associate Editor) etc.