Integrating Ni-MOF/g-C3N4/chitosan derived S-scheme photocatalyst for efficient visible light photodegradation of tetracycline and antibacterial activities

Abstract

Nickel MOF (Ni-MOF) nanoparticles were successfully anchored onto a polymeric graphitic carbon nitride (g-C₃N₄) and Chitosan nanostructure (NS) using an eco-friendly and straightforward synthesis method. These newly fabricated photocatalysts were thoroughly characterized with standard techniques, revealing that the nanoscale Ni-MOF particles were uniformly deposited on the sheet-like g-C₃N₄ matrix. This configuration demonstrated excellent antimicrobial properties and outstanding photodegradation of tetracycline hydrochloride under visible light exposure. The MOF@GC photocatalyst exhibited robust bactericidal activity against pathogens like Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Additionally, it achieved superior visible-light-driven degradation of tetracycline in a significantly shorter time compared to other studies, with approximately 96% of the tetracycline being degraded in just 70 min under visible light. These findings suggest that the effective deposition of Ni-MOF onto the g-C₃N₄ structure reduces the recombination rate of photogenerated electrons and holes, thereby enhancing the photocatalytic efficiency of pure g-C₃N₄ under visible light. The proposed catalytic mechanism, informed by valence band (VB) and conduction band (CB) data from cyclic voltammetry measurements, further supports this conclusion. The MOF@GC photocatalyst is a promising nanostructured material for antimicrobial applications and visible-light-driven photocatalysis.

Keywords: Antibacterial; Drugs; Nanocomposite; Photodegradation; Schiff-base.