ZnO-Nd2O3 nanocomposites: Solution combustion synthesis, structural studies and UV assisted photocatalytic degradation of paracetamol

Abstract

Solution combustion synthesis route was explored for developing ZnO-Nd₂O₃ nanocomposites/heterostructures along with pristine ZnO and Nd₂O₃ using tartaric acid as fuel. From the XRD (X-Ray diffraction) analysis, chemical identity and successful formation of heterostructures was ascertained. Average crystallite size, lattice parameters, microstrain and dislocation density values were evaluated from the XRD data, which were found to be in line with earlier reported studies and suggested the fusing of ZnO and Nd₂O₃crystallites to form bigger composite crystals. Surface characterization and grain size estimation was done using FESEM (Field Emission Scanning Electron Microscopy), which indicated that overall morphology and grain size of ZnO-Nd₂O₃ nanocomposites was an average of individual characteristics of ZnO and Nd₂O₃ nanomaterials. Elemental composition studies were carried out using EDS (Energy Dispersive Spectroscopy), which depicted the high chemical purity of as synthesized samples. Further, preliminary investigations were performed to assess the photocatalytic activities of as prepared samples by subjecting them to the UV assisted degradation of paracetamol. The ZnO-Nd₂O₃ nanocomposites were found to exhibit maximum photocatalytic efficiency followed by ZnO and Nd₂O₃. The high photocatalytic efficiency of heterostructures was attributed to the higher specific surface area and better separation of charge carriers mediated by Nd³⁺ ions. A very little loss of photocatalytic activity was observed for ZnO-Nd₂O₃ heterostructures when recovered and reused for five consecutive cycles, which was attributed to loss of catalyst after each cycle of recovery and preoccupied active sites of adsorption.