The mechanistic pathway of paracetamol degradation using UV/H2O2 with PVP functionalized ZnO Nanorods

Abstract

In the present investigation the mechanistic pathway of photocatalytic degrdation of paracetamol using Polyvinylpyrrolidone (PVP) functionalized ZnO nanorods (NRs) as a photocatalyst and catalysts' photostability have been studied. Pristine ZnO NRs and PVP functionalized ZnO NRs have been successfully synthesized by hydrothermal method. The XRD spectra reveal the polycrystalline nature of the synthesized ZnO NRs and PVP functionalized ZnO NRs. The peaks observed at 457 cm−1 and 446.5 cm−1 in the FT-IR spectra indicate the presence of bonding between Zn metal and oxygen atom in Pristine and PVP functionalized ZnO, respectively. The peaks absorption observed at 376, 373 nm for ZnO NRs and ZnONRs-PVP, respectively. After functionalization with carbonaceous material, a blue shift has been observed, which is due to increase in the crystallite size from ̴ 31 nm to ̴ 59 nm along the (100), (002) and (101) planes. The band gap values for pristine ZnO NRs and ZnONRs-PVP are found to be 3.10 eV, 2.95 eV, respectively, which is found less as compared to that of the bulk ZnO (3.37 eV). The surface morphology shows rod like structure of ZnO with flat edges and flower like structure with pointed edges for the ZnONRs-PVP. The degradation of paracetamol is effective upto 40 ppm concentration with the 200 mg/L of catalyst dose. Nearly 100 % paracetamol (20 ppm) has been successfully removed in 180 min, with the 50 mg/L catalyst dose of ZnONRs-PVP. The resulting quantum efficiencies in the degradation of paracetamol are found to be ̴ 0.10 % for ZnO NRs and 0.13 % for ZnONRs-PVP, respectively. The obtained results demonstrate the synergistic role of surface PVP (carbon) material in the degradation capability of ZnONRs-PVP in efficient removal of paracetamol from water. Therefore, ZnONRs-PVP can be a novel and promising material in wastewater treatment for sustainable future of environmental issues.