UV-Light Assisted High-Performance n-Propanol Sensor Based on Rod-Like Co-Modified ZnO at Room Temperature

Rod-like Co-modified ZnO (Co&ZnO) nanomaterials with high particle purity are prepared by the two-step synthesis process. Meanwhile, the separation efficiency of photogenerated hole-electron pairs, the crystal phase, the surface structure and the absorbance of rod-like Co&ZnO were investigated by different kinds of characterization methods, and the gas-sensitive properties of Co&ZnO sensor to n-propanol under the 365 nm ultraviolet light at room temperature were also studied. The sensing test demonstrates that 3 mol% Co&ZnO sensor has a superior sensitivity value to n-propanol. The sensitivity of 3 mol% Co&ZnO sensor to 100 ppm n-propanol is up to 128% under the 365 nm ultraviolet light at room temperature. Gas-sensing test proved that the superior performance of Co&ZnO can be attributed to the appearance of the number of active sites outside of ZnO caused by Co doping, the unique rod-like morphology of Co&ZnO and the improvement of the separation efficiency of photogenerated hole-electron pairs. In addition, the synthesis of rod-like Co&ZnO nanomaterials is indicative of the direction of future development for the preparation of gas sensors for the monitoring of n-propanol at room temperature.