Photocatalytic small molecules activation

Solar energy conversion and storage into a high energy-density medium, e.g H2 via water splitting, alcohols by CO2 reduction or CH4 conversion, NH3 by nitrogen reduction, has attracted substantial interest over the last decade, which can not only provide renewable fuels but also help developing the carbon-zero economy. The key in these technologies is a photocatalyst, which dominates the current low efficiency in these processes.1,2
Our early studies on charge dynamics in inorganic semiconductors reveal that the moderate solar to fuel conversion efficiency is due to both the fast charge recombination and sluggish reaction kinetics (e.g. water oxidation) on an inorganic semiconductor in these processes,3,4 thus novel material strategies are required to improve the activity of photocatalysts. In the lecture, I will introduce our results on polymer photocatalysts for water splitting5 and CO2 conversion6, in which the charge dynamics was systematically investigated.7 In addition the first example of pure water splitting by a polymer-based Z-scheme under visible light will be presented.8 Very recently we also attempted to release H2 substantially by methanol reforming, which represents a nearly 100% quantum efficiency, a record in this area.9
In parallel we also found that highly dispersed atomic level iron species immobilised on a TiO2 photocatalyst show an excellent activity for methane conversion, resulting into ~97% selectivity towards alcohols operated under ambient conditions by a one-step chemical process.10 Such photocatalyst is also very stable, promising an attractive industrial process of methane upgrade. The dominating function of the iron species has also been investigated in detail. Furthermore, C1 oxygenates can be produced with nearly 100% selectivity by photocatalysis due to the synergy between Au and Cu cocatalysts loaded on ZnO under UV light,11 or over Pd and oxygen vacancy modified In2O3 under visible light irradiation.12 Finally I will brief our results on NH3 synthesis by photocatalysis.13
References
1. Wang, Y., Vogel, A., Sachs, M., Sprick, R.S., Wilbraham,L., Moniz, S.J.A., Godin, R., Zwijnenburg, M.A., Durrant, J.R., Cooper, A.I., Tang, J., Nature Energy, 2019, 4, 746-760.
2. Li, X. Wang, C., Tang, J. Nature Reviews Materials, 2022, Doi: 10.1038/s41578-022-00422-3.
3. Tang, J., Durrant, J. R., Klug, D. R., J. Am. Chem. Soc., 2008, 130 (42) 13885-13891.
4. Ruan, Q., Miao, T., Wang, H., Tang, J., Journal of the American Chemical Society, 2020, 6, 2795-2802.
5. Martin, D. J. Qiu, K., Shevlin, S.A., Handoko, A.D., Chen, X., Guo, Z., Tang, J., Angewandte Chemie International Edition, 2014, 53, 9240-9245.
6. Wang, Y., Liu, X., Han, X., Godin, R., Chen, J., Zhou, W., Jiang, C., Thompson, J.F., Bayazit, M., Shevlin, S., Durrant, J.R., Guo, Z., Tang, J., Nature Communications, 2020, 11, 2531.
7. Godin, R., Wang, Y., Zwijnenburg, M. A., Tang, J., Durrant, J. R., Journal of the American Chemical Society. 2017, 139, 5216–5224
8. Martin, D. J., Reardon, P.J.T., Moniz, S.J.A., Tang, J., J. Am. Chem. Soc., 2014, 136, 12568-12571.
9. Wang, H., Qi, H., Sun, X., Jia, S., Li, X., Miao, T.J., Xiong, L., Wang, S., Zhang, X., Liu, X., Wang, a., Zhang, T., Huang, W., Tang, J., Nature Materials, 2023, 10.1038/s41563-023-01519-y.
10 Xie, J., Jin, R. ,Li, A., Bi, Y., Sankar, G. , Ma D., Tang, J. Nature Catalysis, 2018, 1, 889-896.
11. Luo, L., Gong, Z., Xu, Y., Ma, J., Liu, H., Xing, J., Tang, J., Journal of the American Chemical Society, 2022, 144, 2, 740–750.
12. Luo, L., Fu, L., Liu, H., Xu, Y., Xing J., Chang, C., Yang, D., Tang, J., Nature Communications, 2022, 2022, 13, 2390.
13. Q. Han, C. Wu, , H. Jiao, R. Xu, Y. Wang, J. Xie, Q. Guo, Tang, J., Advanced Materials, 2021, 33, 2008180.