硫掺杂氮化碳纳米微球的制备及光催化杀菌性能研究

Preparation and photocatalytic bactericidal performance of S-doped graphite phase carbon nitridated hollow microspheres

中文关键词:  氮化碳  光催化  大肠杆菌  金黄色葡萄球菌

英文关键词:graphite phase carbon nitride  photocatalysis  Escherichia coli  Staphylococcus aureus

中文摘要:

      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(graphite phase carbon nitride, GCN), 并采用超分子自组装法制成具有微球结构的 GCN, 并在 高温条件下进行硫掺杂(记为 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 GCN 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%, 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 S-GCN 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。

英文摘要:

      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 graphite phase carbon nitride (GCN), followed by a supramolecular self-assembly approach to obtain GCN with a microsphere architecture. Sulfur doping (denoted as 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 Compared with conventional bulk graphene phase carbon nitride, at the microscopic level, sulfur doped carbon nitride nanospheres were round, which increased the specific surface area of the photocatalyst. At the molecular level, S atoms replaced part of N atoms in GCN, formed C-S bonds, and reduced the photogenerated electron-hole recombination rate of the photocatalytic material. In terms of antibacterial activity, the sterilization rates of conventional GCN against Escherichia coli and Staphylococcus aureus were 73.2% and 76.3% within 60 min, while the sterilization rates of S-GCN were 98.8% and 99.9%, which improved the bactericidal performance of photocatalyst. The results of scanning electron microscopy and transmission electron microscopy proved that the photocatalyst could change the morphology of bacteria and destroy the integrity of cell membrane. Conclusion S-GCN nanomicrospheres shows promising disinfection capabilities against foodborne pathogenic bacteria, it is expected to become a new type of food safety control technology.