P, K doped crystalline g-C3N4 grafted with cyano groups for efficient visible-light-driven H2O2 evolution

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-07, Vol.467, p.143379, Article 143379
• Main Authors: Yuan, Jinpeng, Tian, Na, Zhu, Zijian, Yu, Wenyin, Li, Mingtao, Zhang, Yihe, Huang, Hongwei
• Format: Article
• Language: English
• Subjects: Cyano group; g-C3N4; Molten salt method; P doping; Photocatalytic H2O2 production
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143379

•P doped crystalline g-C3N4 was prepared by molten salt post-treatment method.•K ions and terminal cyano group are also introduced into the crystalline g-C3N4.•This co-modified g-C3N4 exhibits the highest charge separation efficiency.•It shows enormously promoted photocatalytic H2O2 production activity. Graphitic carbon nitride (g-C3N4), especially in heptazine forms, has long been considered as a promising non-toxic, benign and sustainable photocatalyst for producing the important chemical and potential green energy H2O2. However, bulk g-C3N4 shows moderate activity originated from its intrinsic drawbacks such as restricted visible-light harvesting ability and sluggish charge separation. Herein, a co-modified crystalline g-C3N4 by P, K ions and cyano group was successfully synthesized via co-thermal polymerization of precursors followed by molten salt treatment. The advanced g-C3N4 exhibits an outstanding photocatalytic H2O2 generation yield of 4424 μmol g−1h−1, more than 81-fold of the pristine counterpart, also superior than that of g-C3N4 processed by single modification treatment. This superior photocatalytic H2O2 evolution efficiency is attributed to the rational design of crystalline g-C3N4, enabling super visible photons capture, more efficient charge carries separation and substantially reduced charge recombination. The current work may furnish an integratable strategy for solar fuel production.