On the construction of hollow nanofibers of ZnO-SnO2 heterojunctions to enhance the NO2 sensing properties

One dimensional ZnO-SnO2 hollow nanofibers were synthesized via a one-step electrospinning method and annealing treatment. The morphology and structure of the nanofibers have been characterized by various analysis methods, and the sensing properties to 0.5-5 ppm NO2 have also been examined. The results reveal that the 20 atm%Zn composite not only exhibits the highest response that is 9 and 5.2 times higher than that of pristine ZnO and SnO2 respectively, but also exhibits rapid response, excellent selectivity and stability at low operating temperature of 90 degrees C. So, herein synthesized composite is a promising sensing material for detection of NO2. The enhancing sensing mechanism is discussed in detail, which is attributed to the unique one-dimensional hollow nanostructures and the formation of heterojunctions at interface between both metal oxides. (C) 2018 Published by Elsevier B.V.