Synthesis and characterization of an antibacterial nanocomposite derived from two metal-organic frameworks for dye adsorption and antibacterial activity applications

In recent years, humans have been forced to create effective water treatment methods because of the increasing water contamination caused by various industrial activities. This study focuses on synthesizing a nanocomposite consisting of two metal-organic frameworks based on ZIF-8 with effective antibacterial characteristics and water-stable, highly porous UiO-66-NH2. After characterizing the synthesized nanocomposite, its application as (i) an adsorbent for methylene blue (MB) removal from a polluted aqueous environment and (ii) an antibacterial agent; was considered. The impact of different factors on the uptake of MB, including dye concentration, adsorption temperature, and the initial pH of the solution, was studied. When the temperature was raised to 45 °C, the maximum adsorption capacity of UiO-66-NH2 @ZIF-8 for MB improved to 215.78 mg/g. Moreover, the pseudo-second-order model accurately described the experimental MB uptake results. According to the thermodynamic analysis, the spontaneous endothermic adsorption process of MB onto the synthesized UiO-66-NH2 @ZIF-8 was the consequence of an entropy impact instead of an enthalpy change. Additionally, the synthesized nanocomposite exhibited antibacterial efficacy against two different bacteria, gram-negative E. coli and gram-positive S. aureus, with a minimum inhibitory concentration (MIC) of 30 mg/L against both strains. The results indicated that the synthesized MOF@MOF nanocomposite is efficient in dye removal for water treatment and has excellent potential in disinfection applications.