Passivated Codoping Can Improve the Solar-to-Hydrogen Efficiency of Graphitic Carbon Nitride

Passivated codoping has never been reported to enhance the solar-to-hydrogen activity of g-C3N4, although it is an effective approach for other materials. In this letter, we use many-body Green’s function theory to analyze the electronic structures, optical absorption spectra, and spatial distribution of electron–hole pair of the doped g-C3N4. Our results suggest that the passivated codoping, such as B+O, could not only extend absorption toward visible range but also promote the separation of photogenerated hole and electron to different parts of g-C3N4. Improvement of photocatalytic activity can be realized only when the n-type and p-type dopants reside in different tris-triazine units of g-C3N4. This manifests the important role of codoping microstructure on solar-to-hydrogen efficiency. These results could provide a guideline for the design of more efficient artificial photocatalysts.