BIO-INSPIRED GREEN SYNTHESIS OF NICKEL NANOPARTICLES USING STERCULIA FOETIDA LEAF EXTRACT AND ITS APPLICATION FOR REMOVAL OF TRIVALENT CHROMIUM FROM AQUEOUS SOLUTION

In the present work, a facile, eco-friendly, and cost-effective approach is described to remove Cr3+ toxic metal ions in an aqueous solution by nickel nanoparticles (NiNPs) synthesized via a green method utilizing Sterculia foetida leaf extract. The synthesized nickel nanoparticles were characterized by EDS (Energy- Dispersive X-Ray Spectroscopy), XRD (X-Ray diffraction), FT-IR (Fourier Transform Infrared Spectroscopy), and FE-SEM (Field Emission Scanning Electron Microscopy) spectroscopic methods. The spectroscopic signature studies revealed that the synthesized NiNPs are of spherical to irregular in shape with a mean particle size of 10±20 nm. The FT IR spectra confirmed the presence of OH, CC and CHO cross-linked stretching, CO and CCl stretching, representing the functional groups of polyphenols, flavonoids, and alkaloids type compounds in the synthesized nanoparticles. The EDS spectra confirmed the presence of nickel in the synthesized nanoparticles with a metal composition of 52.2%. In the XRD spectra, sharp diffraction peak two angles of green-produced NiNPs, which correspond to 111, 200 and 221 crystal planes, confirm the lattice structure of NiNPs. The synthesized NiNPs were used for the reduction of hexavalent chromium from aqueous solutions. The result revealed that immobilization of chromium heavy metals is an effect of initial concentration, ie. 100 µg mL-1 of Cr3+ concentration at 1 g L-1 of NiNPs adsorbent dosage within an average contact time of 1 h at 75 RPM. The present investigation revealed that these newly synthesized NiNPs might be potentially utilized for many environmental remediation applications.