Effect of ultrasonic waves on degradation of phenol and para-nitrophenol by iron nanoparticles synthesized from Jatropha leaf extract

Abstract In this study, Jatropha leaf extract was utilized for the green synthesis of iron nanoparticles. The catalytic degradation efficiency of these nanoparticles was investigated to degrade phenol and p-nitrophenol (PNP) in their respective aqueous solutions. The synthesized nanoparticles were characterized via UV–visible spectroscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The nanoparticles were found to be potent in degrading both pollutants. The maximum degradation values for phenol and PNP were found to be 98.35% and 93.53%, respectively, without the assistance of ultrasonic (US) waves when the initial concentration of both the pollutants was 10 mg/L. In addition, the degradation process was incorporated with ultrasonic waves to enhance the degradation efficiency of the iron nanoparticles. After 30 min, 90%–96% of phenol and 80%–95% of PNP were degraded with decreasing pollutant concentrations from 50 to 10 mg/L. The phenol and PNP degradation were examined using pseudo-first-order and pseudo-second-order kinetics.