Synthesis, characterization and the investigation of CO2 gas sensing properties of Al, Ni, Er and Tb doped 1 dimensional ZnO nanorods

1D ZnO nanostructures were produced via the hydrothermal method by using the ZnO thin film obtained by the sol-gel method as the seed layer. Aluminum and nickel as transition metals and erbium and terbium elements as rare earth elements were doped 1, 3, 5, and 7% by weight to the samples produced. In the structural studies, an improvement was observed in the crystallographic structures of the doped samples compared to the pure samples. It was determined by scanning electron microscopy that the surface morphologies of the samples changed with the doping. Changes in surface morphologies depending on the doping element and its ratio can make the samples usable for different purposes and applications. UV-Vis spectrophotometer and PL were used to examine the optical properties of produced samples. It was observed that the optical transmittance of the produced samples generally decreased with the additive, and the forbidden energy band values calculated from here were examined. To determine the CO2 gas sensing properties of all samples, the optimum operating temperatures at constant gas concentration were determined. Dynamic gas measurements were made of the samples, most of which were found to exhibit the highest gas sensitivity at 500K temperature. As a result of dynamic measurements made at 1, 5, 10, 25, 50, and 100 ppm CO2 gas concentrations, it has been concluded that all samples show acceptable sensitivity. In the measurements made, it was observed that AZ5, EZ5, NZ5 and TZ5 samples with 5% doping exhibited higher sensitivity than others. The response and recovery times of the samples were calculated using the data obtained from the dynamic measurements. It was concluded that the NZ5 sample has the highest sensitivity and best response-recovery times among all samples.