High performance g-C₃N₄ photocatalysts were synthesized via a facile calcining process after mixing dual precursors with different mass ratios, including melamine/thiourea, melamine/urea and urea/thiourea. The g-C₃N₄ samples were systematically characterized and their photocatalytic performances were evaluated by photocatalytic degrading rhodamine B (RhB). g-C₃N₄ prepared from two precursors exhibited better degrading performance than g-C₃N₄ synthesized from single precursor, and the degradation rate constant of g-C₃N₄ prepared from urea and thiourea with mole ratio of 3:1(CN-UT-3) was the largest one, which was about 21.6 times that of g-C₃N₄ prepared from melamine alone. The enhanced specific surface area as well as the accelerated separation and transportation of photogenerated carriers were the main reasons for the improvement of photocatalytic performance. In addition, UV–vis and Mott-Schottky plots showed that an energy band structure like type Ⅱ heterojunction were constructed in as-synthesized g-C₃N₄ samples from dual precursors, whose internal electric field provided the power for the migration of photo-generated carriers. The scavenger experiments revealed that h⁺ and •O₂⁻ were the active groups taking part in the photocatalytic reaction. Moreover, CN-UT-3 exhibited excellent recyclability and stability during the cycle experiments. This work provides a facile way to synthesize g-C₃N₄ with high photocatalytic performance, and reveals the effects of the precursor types and their mole ratios on the structure and photocatalytic performance of the as-synthesized g-C₃N₄ photocatalyst.

在混合具有不同质量比的双前体（包括三聚氰胺/硫脲、三聚氰胺/尿素和尿素/硫脲）后，通过简单的煅烧过程合成了高性能 gC ₃ N _{4光催化剂。}对 gC ₃ N ₄样品进行了系统表征，并通过光催化降解罗丹明 B (RhB) 评估了它们的光催化性能。两种前驱体合成的gC ₃ N _{4比单一前驱体合成的gC 3} N ₄具有更好的降解性能，gC ₃ N ₄的降解速率常数由摩尔比为3:1的尿素和硫脲制备的(CN-UT-3)最大，约为三聚氰胺单独制备gC ₃ N _{4的21.6倍。}比表面积的增加以及光生载流子的分离和传输加速是光催化性能提高的主要原因。此外，UV-vis 和 Mott-Schottky 图表明，在双前体合成的 gC ₃ N ₄样品中构建了类似 Ⅱ 型异质结的能带结构，其内部电场为光生的迁移提供动力运营商。清除剂实验表明，h ⁺和•O ₂ ⁻是参与光催化反应的活性基团。此外，CN-UT-3在循环实验中表现出优异的可回收性和稳定性。这项工作为合成具有高光催化性能的gC ₃ N ₄提供了一种简便的方法，并揭示了前驱体类型及其摩尔比对合成后的gC ₃ N ₄光催化剂的结构和光催化性能的影响。