Fabricating effective heterojunction in metal-organic framework-derived self-cleanable and dark/visible-light dual mode antimicrobial CuO/AgX (X = Cl, Br, or I) nanocomposites

Owing to the alarming consequences of antimicrobial resistance, the requirements for effective antimicrobial materials working under dark and visible-light conditions are on the high rise. On a different note, heterojunctions between semiconductors are highly desirable to enhance the photocatalytic activity of the individual components in a synergistic way. In this work, we address these two aspects in a single material composition through a rationally designed synthetic strategy. Among several candidates, silver and copper are known to exhibit high antimicrobial characteristics in the dark. Besides, CuO and silver halides are known for their visiblelight photocatalytic activity. Hence, a copper-based porous metal organic framework, Cu-BTC, has been deposited with a silver halide followed by calcination to yield CuO/AgX (X = Cl, Br, or I) nanocomposites. The initial deposition of the silver halide over the MOF is envisaged to provide a high dispersion of the halide in the CuO matrix through numerous anchoring pods and thereby result in a tight and effective heterojunction. The nanocomposites obtained through this approach have been characterized structurally and morphologically using various techniques. The nanocomposites have been studied for their visible-light photocatalytic and self-cleaning ability via photodegradation of methylene blue and 4-chlorophenol as model systems. Further, their antimicrobial efficacy has been studied against E. coli and S. aureus both under dark and visible-light conditions. In addition to revealing the high potential of the CuO/AgX nanocomposites towards environmental applications, the synthetic approach presented herein can potentially be extrapolated to fabricate exotic compositions possessing enhanced efficacy.

Automated summary

This work addresses the requirements for antimicrobial materials working under dark and visible-light conditions by designing a synthetic strategy to create CuO/AgX nanocomposites. The nanocomposites exhibit high antimicrobial characteristics and visible-light photocatalytic activity, making them promising for environmental applications.