Polymeric triazine/heptazine imide heterostructures enable photocatalytic O2 reduction to H2O2
Heptazine-based carbon nitrides are a class of transition metal free semiconductors, which are extensively studied in various photocatalytic processes. The localized nature of the excitons, incomplete exciton conversion into the charge-separated state and the recombination of the charge carriers are...
| Autores: | , , , , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2024 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/384942 |
| Acesso em linha: | http://hdl.handle.net/10261/384942 |
| Access Level: | Acceso aberto |
| Resumo: | Heptazine-based carbon nitrides are a class of transition metal free semiconductors, which are extensively studied in various photocatalytic processes. The localized nature of the excitons, incomplete exciton conversion into the charge-separated state and the recombination of the charge carriers are the factors that limit performance of the pristine heptazine-based carbon nitrides. Herein, we design heterojunctions composed of poly(triazine imide) intercalated by LiCl and poly(heptazine imide) phases. The donor-acceptor character of the heterojunctions improves the charge separation yield. The heterojunction with the optimal composition of the phases shows an apparent quantum yield of HO formation of 14 % at 365 nm and 7 % at 465 nm, while the HO production rate reaches 7.8 mol L g h (39 mmol L h produced by 5 mg of photocatalyst) in batch and 15.9 mol kg h in flow using a packed-bed photoreactor. The heterojunction undergoes photocharging under anaerobic conditions. The charges stored in the material after irradiation enable O reduction to HO in the dark with the rate 367 µmol g h (1.8 µmol h stored in 5 mg of photocatalyst). |
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