Green engineered synthesis of PbxZn1-xO NPs: An efficient electrochemical sensor and UV light-driven photocatalytic applications

Abstract

The present work deals with preparation of PbxZn1-xO nanoparticles (NPs) (x = 0, 0.1, 0.3 & 0.5 M) first time using Zingiber officinale leaf as green fuel by solution combustion route and its structural confirmation was achieved by different spectral techniques. Powder-X-ray diffraction (P-XRD) analysis confirmed the switching of dopant Pb ions into host lattice without altering hexagonal wurtzite phase of host ZnO. The impact of Pb dopant directly affects crystallinity of ZnO host lattice changes the surface morphology with noticeable voids and pores with agglomeration examined by Scanning Electron Microscopy (SEM). The decreasing energy band gap of prepared nanoparticles from 3.3 eV − 2.4 eV due to increasing Pb content examined by UV–Visible absorption spectral technique hinders the recombination of electron-holes pairs by trapping e- and h+, which influence the enhanced photocatalytic activities. This optical characterization influences the achieved NPs used as excellent photocatalyst to remove malachite green (MG) dye under visible-light irradiation, which shows 98.5 % dye degradation at 160 min confirmed by its low kinetic constants of photocatalytic degradation of MG dye for Pb doped ZnO (17.42x10-3 min−1) than host ZnO (10.82×10-3 min−1) nanoparticles. The thermodynamics of redox reaction and capacitance measurement of prepared NPs-graphite paste electrode was investigated by electrochemical analysis in a 3-electrode system using 0.1 M KCl in the different scan rates 0.01–0.05 V/s. The excellent variation of redox peak potentials performance on sensor detections, the Pb-ZnO NPS shows an excellent chemical (Paracetamol) and biomolecule (Dextrose) sensing activity due to the region of Pb+2 ions effect.