Photocatalytic and antimicrobial activities of biofunctionalized Ag nanoparticles derived from combustion method

The major global concern for human life is due to the toxic impact of synthetic dyes and hazardous microorganisms (bacteria). In this view, much research is focused on the antimicrobial and photocatalytic activities by preparing metallic-natured metal nanoparticles either through chemical or bio-/green-mediated methods. In this aspect, in the present work, we demonstrate the synthesis of silver nanoparticles (AgNPs) by a simple well-known chemical method, the solution combustion synthesis (SCS) method. The prepared AgNPs were subjected to various structural, optical, antimicrobial, and photocatalytic studies. In particular, we have explored the influence of AgNPs on S. aureus, B. subtilis, P. aeruginosa, and E. coli bacteria to investigate antimicrobial behavior activities. Structural studies by XRD and TEM results reveal the formation of crystalline, nano-sized AgNPs by SCS due to the exothermicity of the fuel used in the synthesis. Optical studies by UV-visible spectroscopy reveal the presence of surface plasmonic resonance (SPR) peak at or around 440 nm, which signifies the formation of AgNPs in accordance with the XRD and TEM results. The synthesized AgNPs demonstrated potential antimicrobial activity against the bacteria S. aureus, B. subtilis, P. aeruginosa, and E. coli. The zone of inhibition surrounding B. subtilis is the most susceptible of the tested bacteria. Furthermore, AgNPs showed remarkable photocatalytic activity in the degradation of indigo carmine dye.