Design and Engineering of Photocatalytic Graphitic Carbon Nitride for Environmental and Biological Disinfection

Photocatalytic antibacterial technologies, leveraging light-driven generation of reactive oxygen species (ROS), offer a promising, antibiotic-free alternative to combat the growing challenge of antibiotic-resistant bacteria. Graphitic carbon nitride (g-C3N4), a nonmetallic photocatalyst, is particularly appealing due to its abundant availability, ease of synthesis, and stability. However, challenges such as limited light absorption, rapid electron–hole recombination, and low surface area restrict its efficiency. This review highlights the synthesis, design strategies, and mechanisms behind g-C3N4’s photocatalytic antibacterial activity, focusing on ROS-induced bacterial inactivation. We discuss key engineering strategies─morphological optimization, chemical doping, heterojunction formation, and carrier confinement domain engineering─that enhance its photocatalytic properties. The review also addresses recent advancements in g-C3N4-based photocatalysis for environmental remediation, including water purification, fouling/corrosion prevention, and biological applications such as wound healing and bone regeneration. This work aims to provide insights into the rational design of g-C3N4 for sustainable, effective disinfection applications across various environmental and healthcare sectors.