Plant Mediated Green Synthesis of Zn–Ni–Se Nanocomposite Using Moringa oleifera Leaf Extract for Environmental Remediation and Antibacterial Applications

Abstract

A Zn–Ni–Se nanocomposite was synthesized through a green co-precipitation method using Moringa oleifera leaf extract as a natural reducing and stabilizing agent. The synthesized material was characterized by XRD, FT-IR, DRS, FE-SEM, EDS, HR-TEM, BET XPS to assess its crystal structure, morphology, elemental composition, surface area, optical properties chemical states. The photocatalytic activity of the nanocomposite was evaluated for the degradation of methylene blue (MB) and reactive red 120 (RR120) dyes under UV irradiation. Under optimized conditions of 50 ppm dye concentration and pH 7, approximately 98% degradation of MB was achieved within 150 min, while RR120 showed about 65% degradation. In addition, antibacterial activity was evaluated against Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae and Pseudomonas aeruginosa using the MIC assay. The nanocomposite exhibited antibacterial activity against the tested bacterial strains at 200 µg/mL. The enhanced multifunctional performance is attributed to the synergistic interaction among Zn, Ni and Se, promoting efficient charge separation, reactive oxygen species generation and antimicrobial activity. The green-synthesized Zn–Ni–Se nanocomposite demonstrates promising potential for dye degradation, antimicrobial applications and sustainable environmental remediation.