Regulating the bandgap of graphitic carbon nitride via Mn doping for boosting visible-light-driven water reduction

As a low-cost and promising photocatalyst, graphitic carbon nitride (g-C3N4) has aroused major interest for accomplishing visible-light-driven H-2 evolution. Nevertheless, rapid recombination of photoexcited electron-holes largely restricts the applications of g-C3N4 in photocatalytic fields. Therefore, metal Mn is introduced into g-C3N4 to tune its bandgap through a simple co-calcination method, effectively improving its photocatalytic performance. Mn doping successfully generates NH-Mn-II bonds, thus enlarging the surface area and shortening the bandgap of g-C3N4 by moving the valence band upwards, which promotes the migration of photogenerated electrons. Mn-doped materials display extensive photocatalytic performance for water reduction. The hydrogen evolution rate for an optimized CN-Mn-0.20 sample can reach 171 mu mol g(-1) h(-1), which is eight times higher than that for pure g-C3N4. This finding is helpful for the bandgap modification of g-C3N4 by introducing a transition metal to promote the visible-light-driven water reduction and other photocatalytic applications.

Automated summary

This article introduces a simple co-calcination method to introduce metal Mn into g-C3N4 to enhance its photocatalytic performance. By modifying the bandgap and surface area, Mn doping successfully improves the migration of photogenerated electrons, thus significantly enhancing the photocatalytic performance for water reduction.