Graphite carbon nitride (g-C₃N₄) has become an emerging metal-free photocatalyst and attracted the attention of researchers. However, pure g-C₃N₄ (PCN) prepared by traditional thermal condensation polymerization has a low polymerization of heptazine ring chains and a large number of charge recombination centers, which hinder in-plane charge transport, leading to undesirable photocatalytic performance. Herein, PCN fabrication by thermal treatment with ammonium oxalate monohydrate was performed to produce highly dispersed porous g-C₃N₄ nanosheets, and the integrity of their in-plane heptazine ring chains was successfully improved without introducing heteroatoms. Electron paramagnetic resonance and ¹³C nuclear magnetic resonance analyses revealed significantly increased electron density and delocalization of the π-conjugated structure. The obtained samples exhibited acceptable stability and photocatalytic activity, and the hydrogen reduction rates without and with the Pt co-catalyst were 11.2 and 5.3 times that of PCN.

石墨碳氮化物(gC ₃ N ₄ )已成为一种新兴的无金属光催化剂并引起了研究人员的关注。然而，传统热缩聚法制备的纯gC ₃ N ₄ (PCN)存在庚嗪环链低聚合度和大量电荷复合中心，阻碍面内电荷传输，导致光催化性能不理想。在此，通过用一水草酸铵进行热处理来制造 PCN，以生产高度分散的多孔 gC ₃ N ₄纳米片，并且在不引入杂原子的情况下成功地改善了它们的面内庚嗪环链的完整性。电子顺磁共振和¹³ C 核磁共振分析表明，π-共轭结构的电子密度和离域显着增加。所得样品表现出可接受的稳定性和光催化活性，在没有和有 Pt 助催化剂的情况下的氢还原率分别是 PCN 的 11.2 和 5.3 倍。