Photocatalytic Disinfection: An Eco-Friendly and Effective Approach to Water Purification

Photocatalytic disinfection is a widely discussed and eco-friendly method that produces effective results. The use of photocarriers and deuterogenic reactive oxygen species (ROS) directly destroys pathogens, without producing secondary pollution or causing drug resistance. Graphitic carbon nitride (GCN) is a non-toxic and commonly used layered metal-free photocatalyst with a suitable energy band structure and stable chemical properties. However, original GCN has shown less than ideal results in water disinfection, mainly due to the following reasons: firstly, microorganisms are more resistant to the attack of ROS due to their complex life activities, self-repair, and strong defense systems, especially fungi with thick and complicated cell walls. Secondly, ROS have a very short lifetime, and cannot persistently damage microbes, resulting in the potency of the active substance being seriously inhibited and wasted in cases of insufficient contact between catalyst and target. Lastly, GCN has a low specific surface area, which leads to a shortage of active sites, and easy recombination of photogenerated carriers, resulting in less ROS produced.