In-situ synthesis of defects modified mesoporous g-C3N4 with enhanced photocatalytic H2 evolution performance

Organic polymer g-C3N4 with photocatalytic ability has become a heated discussion. Because of terrible electronic structure and small surface area, the pristine g-C3N4 (CN) exhibited weak catalytic performance. Herein, a novel strategy was applied for preparing defect modified mesoporous g-C3N4 (DMCN). Compared with CN (0.26 mmol h(-1) g(-1)), DMCN showed remarkable enhanced visible-light photocatalytic activity for H-2 production (3.29 mmol h(-1) g(-1)) under the same conditions (Pt co-catalyst). Through a great many of characterizations, it was found that excellent photocatalytic activity of DMCN is due to synergistic influence of mesoporous structure and defects (cyano groups and N-vacancies). On the one hand, the formation of mesoporous structure provides more catalytic sites by increasing specific surface area. On the other hand, the introduction of defects benefits to promote the separation efficiency of photoexcited charges and enlarge visible-light absorption range. Thus, this work detailedly reveals the effect of defects and mesopores on the physicochemical property of g-C3N4, which might provide referred role for the preparation of other photocatalysts with defects or porous structure.

Automated summary

This study focuses on enhancing the activity of g-C3N4 in photocatalysis by introducing defect-modified mesoporous structures, showing that DMCN exhibits better catalytic performance compared to CN. The improved photocatalytic activity is attributed to the increase in catalytic sites and the promotion of charge separation efficiency through the introduction of defects.