The synthesis of graphitic carbon nitride/cadmium sulfide core-shell nanofibers has been studied for the improved photodegradation of methylene blue (MB) dye. The enhancement in photocatalytic activity in g-C3N4@CdS core-shell nanostructures has been increased by controlling the thickness of the CdS shell. Additionally, the favorable bandgap, suitable band positions, and high thermal stability played an important role to enhance the photodegradation rate of catalysts. g-C3N4@CdS core-shell nanofiber arrays were synthesized by using a simple two-step process. g-C3N4 nanofiber (gcnf) was synthesized by using a simple polycondensation method and followed by a surface modification step for the deposition of CdS nanoparticles. The characterization of core-shell nanofibers and their photocatalytic activity was examined by powder X-ray diffraction, UV-Vis spectrophotometer, FESEM, EDS, and TEM microscopy. g-C3N4@CdS core-shell nanofibers (gcnf/CdS, 0.38; gcnf/CdS, 0.19; and gcnf/CdS, 0.09) showed enhanced photocatalytic degradation efficiency of ~ 98% in 40, 50, and 70 min, respectively. Pristine g-C3N4 nanofibers and CdS nanoparticles displayed the photodegradation efficiency of ~ 98% in 100 and 170 min, respectively. gcnf/CdS, 0.38 core-shell nanofibers (0.38 M of citric acid), offered the highest photodegradation rate of 0.0624 min-1, which is ~ 2.5- and 3-fold higher than pristine g-C3N4 nanofibers and CdS nanoparticles, respectively. The increase in the photodegradation rate of the g-C3N4@CdS core-shell nanostructure is due to the synergetic effect of g-C3N4 and CdS. Thus, the present work highlights the enhanced photocatalytic activity and stability of g-C3N4@CdS core-shell nanofibers and found to be useful in energy harvesting and environmental remediation applications.

中文翻译：

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用于增强光催化的石墨氮化碳/硫化镉核壳纳米纤维的合成。

已经研究了石墨氮化碳/硫化镉核壳纳米纤维的合成，以改善亚甲蓝 (MB) 染料的光降解。通过控制 CdS 壳的厚度，可以提高 g-C3N4@CdS 核壳纳米结构的光催化活性。此外，良好的带隙、合适的能带位置和高热稳定性对提高催化剂的光降解速率起到了重要作用。g-C3N4@CdS 核壳纳米纤维阵列是通过简单的两步法合成的。g-C3N4 纳米纤维 (gcnf) 是通过使用简单的缩聚方法合成的，然后是用于沉积 CdS 纳米颗粒的表面改性步骤。通过粉末X射线衍射检查核壳纳米纤维的表征及其光催化活性，紫外可见分光光度计、FESEM、EDS 和 TEM 显微镜。g-C3N4@CdS 核壳纳米纤维（gcnf/CdS，0.38；gcnf/CdS，0.19；gcnf/CdS，0.09）分别在 40、50 和 70 分钟内显示出增强的~98% 的光催化降解效率。原始的 g-C3N4 纳米纤维和 CdS 纳米颗粒分别在 100 和 170 分钟内显示出~98% 的光降解效率。gcnf/CdS，0.38 核壳纳米纤维（0.38 M 柠檬酸），提供最高的光降解率 0.0624 min-1，分别比原始 g-C3N4 纳米纤维和 CdS 纳米颗粒高约 2.5 倍和 3 倍。g-C3N4@CdS核壳纳米结构光降解率的增加是由于g-C3N4和CdS的协同作用。因此，