Molecular doping of carbon nitride photocatalysts with tunable bandgap and enhanced activity

Molecular doping of conjugated carbon nitride (CN) with thiophene donors was applied for the modification of CN photocatalysts. The incorporation of electron-rich thiophene entities in the conjugated polymer matrix can effectively change the intrinsic bulk and surface features of CN, such as engineering the electronic structure with tunable bandgap and promoting the charge-carrier migration and separation via forming surface dyadic structures. A significant alteration in the texture, morphology, and crystalline was also observed for the thiophene-modified CN samples. The combined benefits of the molecular doping in terms of bulk, surface, and texture properties lead to an improvement in the photocatalytic activity for H2 generation with visible light, which underlines the importance of organic chemistry protocols for the chemical modification of newly developed metal-free, polymeric photocatalysts.

Graphical abstractMolecular doping of carbon nitride with thiophene donors can effectively extend the π conjugated system to optimize its physiochemical properties for photocatalytic hydrogen evolution.Figure optionsDownload full-size imageDownload high-quality image (47 K)Download as PowerPoint slideHighlights► Doping with thiophene can effectively extends the π conjugated system of carbon nitride. ► Doping effect is predicted by DFT calculations. ► Control to narrowing the bandgap is achieved via varying the use of thiophene content. ► Both of the electronic features and surface structure are altered by doping. ► Integrating thiophene in carbon nitride greatly enhances the photocatalytic performance.