Nanomesh-Structured Graphitic Carbon Nitride Polymer for Effective Capture and Photocatalytic Elimination of Bacteria

It is valuable to design a photocatalyst semiconductor architecture that enables the effective contact with bacteria, since only random and momentary contact exists in most of the present photocatalytic antibacterial systems. Herein, nanomesh-structured graphitic carbon nitride (g-C3N4) a visible-light photocatalyst was successfully prepared using SiO2 microspheres as template. The optimal pore size in the g-C3N4 nanomesh was determined at the average diameter of about 500 nm of SiO2 microspheres, which matches the size of E.coli K-12. Excluding the effect of electrostatic contact, the efficient contact between catalyst and bacteria was achieved, leading to increased capture and reaction time for killing bacteria. The porous structure promoted the light absorption and realized more active edge. As a result, the photocatalytic antibacterial activity and the leakage of K+ ions was greatly enhanced via (OH)-O-. radical as the main active species. This work provided a new approach to photocatalytic sterilization for practical applications.