Bandgap Engineering of Organic Semiconductors for Highly Efficient Photocatalytic Water Splitting |
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| Authors: | Yiou Wang Fabrizio Silveri Mustafa K. Bayazit Qiushi Ruan Yaomin Li Jijia Xie C. Richard A. Catlow Junwang Tang |
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| Affiliation: | 1. Solar Energy and Advanced Materials Group, Department of Chemical Engineering, UCL, London, UK;2. School of Chemistry, University of Cardiff, Cardiff, UK |
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| Abstract: | The bandgap engineering of semiconductors, in particular low‐cost organic/polymeric photocatalysts could directly influence their behavior in visible photon harvesting. However, an effective and rational pathway to stepwise change of the bandgap of an organic/polymeric photocatalyst is still very challenging. An efficient strategy is demonstrated to tailor the bandgap from 2.7 eV to 1.9 eV of organic photocatalysts by carefully manipulating the linker/terminal atoms in the chains via innovatively designed polymerization. These polymers work in a stable and efficient manner for both H2 and O2 evolution at ambient conditions (420 nm < λ < 710 nm), exhibiting up to 18 times higher hydrogen evolution rate (HER) than a reference photocatalyst g‐C3N4 and leading to high apparent quantum yields (AQYs) of 8.6%/2.5% at 420/500 nm, respectively. For the oxygen evolution rate (OER), the optimal polymer shows 19 times higher activity compared to g‐C3N4 with excellent AQYs of 4.3%/1.0% at 420/500 nm. Both theoretical modeling and spectroscopic results indicate that such remarkable enhancement is due to the increased light harvesting and improved charge separation. This strategy thus paves a novel avenue to fabricate highly efficient organic/polymeric photocatalysts with precisely tunable operation windows and enhanced charge separation. |
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| Keywords: | bandgap organic semiconductors photocatalytic polymers water splitting |
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