Heavy metal detection in industrial waste water using Ficus Benjamina leaf extract–mediated Ag nanoparticles

Polycrystalline Ag NPs were synthesized by environment benign and cost-effective green route method using Ficus Benjamina leaf extract (FBLE). As-synthesized Ag NPs were characterized using various techniques such as X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic absorption spectroscopy (AAS). Structural analysis was carried out by employing the Rietveld refinement method which revealed that FBLE: Ag NPs exhibited face-centered cubic crystallinity with space group \(Fm\overline{3 }m\) $Fm\overline{3}m$ and space group no. 225. FTIR spectra displayed the existence of phytochemicals such as phenols belonging to the hydroxyl group (–OH) as bending vibration appeared at 3435 cm⁻¹ and 1638 cm⁻¹, respectively. Surface morphology and microstructure of FBLE: Ag NPs were depicted using FESEM and it was observed that biosynthesized Ag NPs showed well interlinked and homogenous distribution of grains with an average grain size of 31.12 ± 0.44 nm. FBLE: Ag NPs were used to detect heavy metals such as lead (Pb), cadmium (Cd), and zinc (Zn) present in industrial waste water of different factories including textile, steel, and chemical. The maximum removal efficiency for Pb, Cd, Zn, and Cr was found to be 96.2%, 94.4%, 93.2%, and 82.6% which was observed after 90 min at 1 g/L concentration of FBLE: Ag NPs.