Sharma D, Verma R, Chauhan A, Kumari S, Thakur P, Kumar V, Sharma M, Kumar P, Mahajan AK. Soapnut plant–mediated ZnO and Ag-ZnO nanoparticles for environmental and biological applications. Emergent Materials. 2023 Dec;6(6):1841-62. https://doi.org/10.1007/s42247-023-00564-2
Abstract
Herein, zinc oxide (ZnO) and silver-doped Zinc oxide (Ag-doped ZnO) nanoparticles (NPs) are synthesized via green method using Sapindus mukorossi fruit (soapnut) as a reducing and stabilizing agent. Qualitative and quantitative phytochemical screening was done for the aqueous fruit extract of soapnut. The X-ray diffraction (XRD) pattern confirmed the formation of pure NPs without any impurity phase with hexagonal wurtzite structure. The crystallite size is observed to decrease from 21.87 to 21.67 nm with Ag-doping, whereas lattice parameters increased from (a = b) 3.048 to 3.165 Å. The c/a ratio remains the same for both pristine and doped NPs. The Fourier transform infrared (FTIR) spectroscopy shows the peak at 577 cm−1 and 574 cm−1 for ZnO and Ag-ZnO, respectively. The ultraviolet visible (UV-Vis) spectroscopy shows that the band gap decreases from 3.05 to 2.99 eV with Ag doping in the ZnO lattice. The field emission scanning electron microscope (FESEM) investigation reveals the flower-like morphology for pristine and doped NPs, whereas energy dispersive X-ray spectroscopy (EDS) shows the chemical purity of both the samples. X-ray photoelectron spectroscopy (XPS) confirms the presence of all the elements in their required oxidation state. Both the samples show excellent photocatalytic activity against Methylene blue dye, where the efficiency is 96.06% and 98.33% for the ZnO and Ag-ZnO NPs, respectively. The antibacterial activity is observed (14.6 ± 0.61 mm) highest against Salmonella typhi for Ag-ZnO NPs. Thus, the synthesized ZnO and Ag-ZnO NPs using soapnut fruit extract are observed to have excellent water purification and biomedical applications. This study can further pave the way forward for the use of Himalayan plants as potential candidates for improving the properties of metal-oxide (MO) NPs.