Copolymerization of urea and small molecules is an effective strategy to modify g-C₃N₄. To study in depth the important effects of the introduction of a small molecule moiety on the structure–property relationship of g-C₃N₄, in this paper, the copolymers M_xCN (x = 5, 15, 25, 50, 100 mg) were synthesized from urea melt and different amounts of small molecule murexide by a one-pot method. The experimental results confirm that the addition of small molecule murexide can evoke the synergistic effect of reduced band gaps, enhanced visible light absorption and improved separation efficiency of photogenerated carriers. Benefiting from these merits, the optimized M₂₅CN exhibits superior photocatalytic hydrogen production performance (6.1 mmol g⁻¹ h⁻¹) with an apparent quantum efficiency of about 7.5% at 420 nm, which is about five times higher than that of pristine CN. The degradation rate of tetracycline is about 97.6% in 2 h, and a possible degradation mechanism is proposed. This work provides a reference for the study of the effect of small molecule modified g-C₃N₄ on the photocatalytic performance.

中文翻译：

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尿素和灭鼠灵的共聚反应可有效地光催化制氢和降解四环素

尿素和小分子的共聚是改性gC ₃ N ₄的有效策略。为了深入研究引入小分子部分对gC ₃ N ₄的结构-性质关系的重要影响，在本文中，共聚物为M _x CN（x = 5，15，25，50，100 mg）通过一锅法从尿素熔体和不同量的小分子莫来昔特合成尿素。实验结果证实，添加小分子莫来塞德可以引起减小的带隙，增强的可见光吸收和提高的光生载流子分离效率的协同作用。受益于这些优点，优化的M ₂₅CN表现出优异的光催化制氢性能（6.1 mmol g ^-1 h ^-1），在420 nm处的表观量子效率约为7.5％，约为原始CN的五倍。在2小时内四环素的降解率约为97.6％，并提出了可能的降解机理。这项工作为研究小分子修饰的gC ₃ N ₄对光催化性能的影响提供了参考。