The development of photoluminescent (PL) properties in graphitic carbon nitride (g-C₃N₄) has been limited by their short PL wavelength. Herein, we synthesized tunable multi-color emissive cyanuric acid-supported g-C₃N₄ materials (CNS) via a one-pot microwave-assisted method using urea and thiophene-3,4-dicarboxylic acid (TDC) as starting materials. By varying the TDC amount, the solid-state emissive color of CNS samples can be manipulated from blue to orange-red. The incorporation of thiophene ring into the g-C₃N₄ framework during microwave synthesis enlarges the π-conjugation system, narrowing the band gap from 3.94 to 1.91 eV, as verified by the DFT calculations. The hydrogen-bond networks from cyanuric acid-supported g-C₃N₄ improves the framework crystallinity, enabling the high emission efficiency (quantum yields up to 0.27). These properties make CNS highly suitable for multi-color light-emitting diodes (LED) applications, particularly in WLEDs with chromaticity coordinates (0.341, 0.359). Additionally, this study pioneers the use of CNS as a solid-state fluorescent probe for Fe³⁺, expanding its optical application fields. Our findings suggest significant potential for CNS_x materials in advanced LED lighting solutions, with broad applicability in illumination, information encryption, and anti-counterfeiting.

中文翻译：

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高发光氰尿酸负载氮化碳杂化物，用于多色发光二极管和固态荧光传感


石墨氮化碳 （g-C ₃ N ₄ ） 中光致发光 （PL） 性能的发展受到其短 PL 波长的限制。在此，我们以尿素和噻吩-3,4-二羧酸 （TDC） 为起始原料，通过一锅法微波辅助方法合成了可调多色发射氰尿酸负载的 g-C ₃ N ₄ 材料 （CNS）。通过改变 TDC 量，可以将 CNS 样品的固态发射颜色从蓝色控制到橙红色。正如 DFT 计算所验证的那样，在微波合成过程中将噻吩环掺入 g-C ₃ N ₄ 框架中扩大了π共轭系统，将带隙从 3.94 eV 缩小到 1.91 eV。由氰尿酸负载的 g-C ₃ N ₄ 产生的氢键网络提高了框架结晶度，实现了高发射效率（量子产率高达 0.27）。这些特性使 CNS 非常适合多色发光二极管 （LED） 应用，尤其是在色度坐标为 （0.341， 0.359） 的 WLED 中。此外，本研究开创了使用 CNS 作为 Fe 的固态荧光探针 ³⁺ ，扩大了其光学应用领域。我们的研究结果表明，CNS _x 材料在先进的 LED 照明解决方案中具有巨大潜力，在照明、信息加密和防伪方面具有广泛的适用性。