Synthesis, characterization, and gas sensing application of crumpled CdO sheets prepared in alkaline media

CdO crumpled sheets have been synthesized by microwave-assisted irradiation in alkaline solutions of NH4OH and NaOH, respectively, and in presence of a surfactant. The morphology of CdO samples have been investigated using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). X-ray diffraction analysis (XRD) has been used to determine the cadmium oxy/hydroxide crystalline phases of CdO formed during synthesis and successive annealing at 300 degrees C. Crystallite sizes of CdO nanostructures obtained from NH4OH and NaOH reagent-assisted synthesis are 44 nm and 57 nm, respectively. The specific surface area (SSA), lattice parameter, X-ray density, dislocation density, macrostrain, and texture coefficient (TC), have also been deter-mined. The optical characteristics of CdO samples were investigated using UV reflectance (DRS) and K-M plot. NO2 gas detecting capabilities of CdO nanostructures have been investigated at low working temperature of 150 degrees C. When compared to its NaOH counterpart, the CdO sample prepared by NH4OH reagent-assisted synthesis demonstrated a superior sensitivity to NO2, being demonstrated even at the low concentration of 0.14 ppm, with excellent selectivity.

Automated summary

CdO crumpled sheets were synthesized by microwave-assisted irradiation in alkaline solutions of NH4OH and NaOH, respectively, with the presence of a surfactant. The morphology of CdO samples was characterized by SEM and TEM. XRD analysis revealed the crystalline phases of CdO formed during synthesis and annealing at 300°C. The CdO nanostructures prepared using NH4OH showed superior sensitivity to NO2, with detection even at a low concentration of 0.14 ppm, and excellent selectivity compared to the CdO sample prepared using NaOH.