Gas sensing properties of Cd-doped ZnO nanofibers synthesized by the electrospinning method

Abstract

We used electrospinning followed by thermal treatment to successfully synthesize Cd-doped ZnO nanofibers using different doping concentrations. The research interest is aimed at achieving a significant enhancement of the sensing performance toward CO, which was achieved due to the doping changing the state of the native defect of the ZnO, and which has been confirmed by PL and XPS spectra. The competitive influence of the specific surface and the crystallinity of the ZnO on sensing response is discussed in detail. The sensing mechanism of Cd-doped ZnO sensors for the detection of CO is also discussed. In addition, the band structures and densities of the states for undoped and Cd-doped ZnO were also calculated using first-principles based on a local density approximation LDA + U scheme. The calculated results show that the band gap is significantly narrowed by doping, which concurs with the results determined from UV-Vis spectra.