High response n-propanol sensor based on co-modified ZnO nanorods

Co-modified ZnO (Co@ZnO) nanorods are successfully prepared by hydrothermal synthesis method without secondary pollution. The element distribution, microstructure, crystal plane spacing, and other related parameters of Co@ZnO nanorods are systematically studied by adopting different material characterization methods. It can be concluded that Co nanoparticles are decorated on the outside of ZnO nanorods. Gas sensing tests demonstrate that Co@ZnO sensor has a significant improvement for the detection of n-propanol in response time, response value, and detection lower limit. In particular, the response value of 1 mol % Co@ZnO sensor to 100 ppm n-propanol is 491 at 250 degrees C, which is about 3 times than the response value of ZnO sensor at 275 degrees C. The minimum detection limit of 1 mol% Co@ZnO sensor for n-propanol has been reduced to 10 ppb with the response value of 3.14, which has reached the minimum detection limit for npropanol by contrast with other literature report for the detection of n-propanol. The improvement of gas sensing properties of Co@ZnO nanorods is discussed by its catalytic oxidation of n-propanol, special nanorods morphology, and fermi level shift of ZnO triggered by Co doping. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Co@ZnO nanorods with co-modification were successfully prepared by hydrothermal synthesis method without secondary pollution. The gas sensing tests show that the Co@ZnO sensor has a significant improvement in detecting n-propanol with faster response time and lower detection limit.