Target-oriented functionalization: Turning carbon nitride into a round-the-clock antimicrobial photocatalyst in water disinfection

Abstract

The high-efficient and continuous disinfection of water by photocatalysis is still a challenging issue. Herein, a target-oriented functionalization was molecularly engineered to turn carbon nitride into a round-the-clock antimicrobial photocatalyst for water disinfection. Artfully, N,N-bis(2-hydroxyethyl)-N-methyldodecan-1-aminium chloride (2HMAC-12) was grafted onto graphitic carbon nitride by covalent condensation. The grafted 2HMAC-12 was capable of inducing a disruption effect on electrostatic attraction and lipophilic alkyl towards microorganisms, while simultaneously improving the separation and migration of photogenerated carriers. A win–win antimicrobial photocatalyst with high-efficient and round-the-clock water disinfection was established, including a short-term mode for photocatalytic disinfection and a long-term mode for bacteriostasis and fungistasis. For pathogen-rich water, the photocatalytic disinfection efficiency of Escherichia coli and Staphylococcus aureus reached 99.9999% within 16 min. Impressively, the dormant spores of Aspergillus fumigatus could be eliminated over 99%. More importantly, the functionalized photocatalyst could continuously inhibit the proliferation of microorganisms over 24 h without irradiation. Our findings probably provide important implications for the design of effective modification strategies for photocatalysts against pathogenic microorganisms.