硫掺杂氮化碳纳米微球的制备及光催化杀菌性能

目的 制备硫掺杂氮化碳纳米微球，并对其光催化杀菌性能进行研究。方法 采用一步法制备常规石墨烯相氮化碳（g-C3N4，GCN），并采用超分子自组装法制成具有微球结构的g-C3N4，并在高温条件下进行硫掺杂（S-GCN）。通过X射线衍射，X射线光电子能谱以及傅里叶红外光谱等方法对制备的纳米微球材料进行表征，通过平板计数法来验证该材料对大肠杆菌和金黄色葡萄球菌的光催化杀菌效果，并采用扫描电镜和透射电镜观察杀菌前后的细菌形态和细胞膜完整性。结果 与常规块状石墨烯相氮化碳相比，在微观层面，硫掺杂氮化碳纳米微球呈圆形，此结构使光催化剂的比表面积增加，在分子层面，S原子取代g-C3N4中部分N原子，形成C-S键，降低了光催化材料的光生电子-空穴复合速率。在抗菌活性方面，常规GCN在60 min内对大肠杆菌和金黄色葡萄球菌灭菌率是73.2%和76.3%，而S-GCN灭菌率则达到98.8%和99.9%，显著提高了光催化剂的杀菌性能。扫描电镜和透射电镜的结果证明，光催化剂能够改变细菌形态以及破坏细胞膜的完整性。结论 硫掺杂氮化碳纳米微球对食源性致病菌有较好的灭活能力，有望成为新型食品安全控制技术。

Preparation and sterilization efficiency of S-doped graphite phase carbon nitridated hollow microspheres

ABSTRACT：Objective To preparation of Sulfur-Doped Nitrogen-Carbon Nanospheres and Investigation of Their Photocatalytic Antibacterial Performance. Methods A one-step synthesis method was used to prepare conventional graphitic carbon nitride (g-C3N4, GCN), followed by a supramolecular self-assembly approach to obtain GCN with a microsphere architecture. Sulfur doping (S-GCN) was then performed at elevated temperatures. The nanomaterials were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The photocatalytic bactericidal effectiveness against Escherichia coli and Staphylococcus aureus was evaluated using the plate counting method. Scanning electron microscopy and transmission electron microscopy were used to observe morphological changes and cell membrane integrity of bacteria before and after the photocatalytic sterilization process. Results The results showed that sulfur-doped nitrogen-carbon nanomicrospheres exhibited a circular morphology at the microscopic level, providing a higher specific surface area for the photocatalyst. Sulfur atoms replaced some nitrogen atoms in g-C3N4, forming C-S bonds at the molecular level. In terms of antibacterial activity, conventional GCN achieved disinfection rates of 73.2% and 76.3% against Escherichia coli and Staphylococcus aureus within 60 minutes, while S-GCN demonstrated significantly improved disinfection rates of 98.8% and 99.9%. Scanning electron microscopy and transmission electron microscopy results showed that the photocatalyst effectively altered bacterial morphology and disrupted cell membrane integrity. Conclusion Sulfur-doped nitrogen-carbon nanomicrospheres showed promising disinfection capabilities against foodborne pathogenic bacteria, suggesting their potential as a candidate for novel food safety control technologies.