Green synthesis of ZnO NPs using Pontederia crassipes leaf extract: characterization, their adsorption behavior and anti-cancer property.

The fabrication of nanoparticles by green routes is gaining extensive attention owing to their reliability, sustainability, being eco-friendly, cost-effectiveness, high productivity, and purity and biocompatibility. In the current study, zinc oxide nanoparticles (ZnO NPs) were successfully fabricated via green route using leaf extract of Pontederia crassipes. The synthesized sample was characterized by various techniques, such as FT-IR, XRD, BET, FEEM, TEM, and EDS. The characterization results confirmed the success of the synthesis process, with prepared ZnO NPs exhibiting good purity. The synthesized ZnO NPs were employed as an adsorbent for the removal of carcinogenic anionic congo red (CR) and cationic malachite green (MG) dyes from aqueous solutions. All experiments were performed in a batch process where the effects of dye concentration, adsorbent dose, equilibrium time, temperature, pH, and salinity have been investigated. High removal capacity of 96.39% for CR was achieved with pH 2, dye concentration of 40 mg/L, and adsorbent dosage of 1.2 g within 30-min equilibration time. On the other hand, the maximum adsorption efficiency for MG dye was 95.75% with pH 7, dye concentration of 15 mg/L, and ZnO dosage of 1.2 g within 60-min equilibration time. The Temkin and Freundlich isotherm models match the dye adsorption process for CR and MG, respectively. Depending on the thermodynamic functions, it was proven that the adsorption process for both dyes is endothermic and spontaneous. Employing ZnO as anti-breast cancer (MCF7 cancer cell line) was also studied. ZnO NPs exhibit high in vitro cytotoxic efficacy against cancerous MCF7 (IC₅₀ = 39.3 μg/mL. [ABSTRACT FROM AUTHOR]