The inactivation mechanism of pathogenic microorganisms in water needs to be comprehensively explored in order to better guide the development of an effective and green disinfection method for drinking water safety. Here, metal-free modified g-C₃N₄ was prepared and used to inactivate two typical bacteria (namely, Gram-positive E.coli and Gram-negative S. aureus) in water under visible light from a comparative perspective. These two bacteria could be inactivated in the presence of modified g-C₃N₄ within 6 h of visible light, but their inactivation kinetics were quite different. E. coli were inactivated slowly in the early disinfection stage and rapidly in the later disinfection stage, whereas S. aureus were inactivated steadily during the entire disinfection process. Moreover, the impacts of important water parameters (pH, salt, temperature, and water matrix) on photocatalytic inactivation of E. coli and S. aureus were also distinct. In addition, scavenger experiments indicated that superoxide radicals played the most important role in E. coli inactivation, while both superoxide and hydroxyl radicals were important for S. aureus inactivation. Quantitative changes in fatty acids, potassium ions, proteins and DNA of the bacterial suspensions suggested that the higher resistance of E. coli in the early inactivation stage could be originated from the difference in the phospholipid repair system in cell membrane structures. This study can provide new insights into research and development of a safe and effective disinfection technology for drinking water.

需要全面探索水中病原微生物的灭活机理，以更好地指导饮用水安全绿色高效消毒方法的发展。在这里，制备了无金属的修饰的gC ₃ N ₄，并从比较的角度将其用于在可见光下灭活水中的两种典型细菌（即革兰氏阳性大肠杆菌和革兰氏阴性金黄色葡萄球菌）。这两种细菌可以在可见光下6小时内在修饰的gC ₃ N ₄存在下失活，但是它们的失活动力学却大不相同。大肠杆菌金黄色葡萄球菌在早期消毒阶段缓慢失活，在后期消毒阶段迅速失活，而金黄色葡萄球菌在整个消毒过程中稳定地失活。此外，重要的水参数（pH，盐，温度和水基质）对大肠杆菌和金黄色葡萄球菌的光催化失活的影响也很明显。此外，清除剂实验表明，超氧自由基在大肠杆菌的灭活中起着最重要的作用，而超氧自由基和羟自由基对金黄色葡萄球菌的灭活都非常重要。细菌悬浮液中脂肪酸，钾离子，蛋白质和DNA的定量变化表明，该菌株的抗药性较高。处于灭活初期的大肠杆菌可能源于细胞膜结构中磷脂修复系统的差异。这项研究可以为研究和开发一种安全有效的饮用水消毒技术提供新的见解。