Surface functionalization of porous In2O3 nanofibers with Zn nanoparticles for enhanced low-temperature NO2 sensing properties

Different from the dominant method of surface modification of metal oxide sensing materials with noble metals, a simple and low-cost method is developed by using Zn nanoparticles as a surface modifier in this work. The first step involves the fabrication of porous In2O3 nanofibers by an electrospinning technique, and then Zn nanoparticles decorated In2O3 nanofibers are constructed by a simple thermal evaporation method. An increase in surface O-2(-) species absorbing capability and a decrease in sensor resistance are observed by surface modification of In2O3 nanofibers with Zn nanoparticles. In comparison with pure In2O3 nanofibers, this kind of Zn-In2O3 composite nanofibers display higher response and better selectivity to NO2. The response of Zn-In2O3 nanofibers is up to 130.00-5 ppm NO2 at 50 degrees C, which is 13.7 times higher than that of pure In2O3. From our perspective, the improved NO2 sensing performances of Zn-In2O3 composite nanofibers are mainly attributed to the enhanced resistance modulation because of the formation of ohmic contacts between Zn nanoparticles and In(2)O(3)nanoparticles.