Synthesis of Ag-Ag2O nanoparticles using Ageratum conyzoides leaf extract for the catalytic reduction of nitrobenzene and methylene blue and antibacterial applications

The 4-nitrophenol (4-NP) and methylene blue (MB) are commonly used in many industries and remain in the industrial effluent. They have an adverse effect on the environment if not treated properly. Therefore, it is essential to develop a convenient method to remove such toxic chemicals from wastewater. Here, Ag/Ag₂O nanoparticles (NPs) were prepared from AgNO₃ (0.05 M) using Ageratum conyzoides L. agricultural weed extract (50 mL) in an ultrasonic bath. Then, the synthesized Ag/Ag₂O NPs were utilized for the 4-NP and MB reduction in the presence of NaBH₄. The Ag/Ag₂O NPs efficiently reduce 4-NP to 4-AP and MB to LMB in an aqueous medium. In the case of 4-NP, about 93% of the reduction was achieved in about 10 min at optimum conditions, 2 mL of 4-NP (0.15 mM) and 100 µL of NaBH₄ (50 mM) in the presence of 1 mg Ag/Ag₂O NPs. About 94% reduction of MB dye was achieved in about 6 min at optimum conditions, 2 mL of MB (10 ppm) and 100 µL of NaBH₄ (30 mM) using 1 mg Ag/Ag₂O NPs. Furthermore, the bactericidal activity of Ag/Ag₂O NPs was studied against S. Mutans, B. Subtilis, and E. coli.