Design and Synthesis of Parallel Bicomponent Heterojunction Nanofibers as Flexible Room-Temperature Sensors for Ppb-Level NO₂ Detection

Enhancing the stability and selectivity of flexible room-temperature gas sensors has been of extensive concern for their practical application. However, it is very challenging to combine the integration of excellent mechanical flexibility and outstanding gas sensing properties. This study presents the design of a parallel structure of ZnO//In2O3 bicomponent nanofibers using a homemade V-type dual-channel electrospinning technique. Compared with as-electrospinning pure ZnO nanofibers and pure In2O3 nanofibers, the ZnO//In2O3-2 composite nanofibers showed higher response and low detection line NO2 at room temperature. The ZnO//In2O3-2 nanofibers have a maximum high response of 109.84 to 60 ppm of NO2 at room temperature, which is about 8.44 times higher than that of the pure In2O3 nanofibers. Moreover, the theoretical detection limit for NO2 is determined to be 1.99 ppb. We have investigated the excellent flexibility of the gas sensor for potential application. These findings indicate that the flexible ZnO//In2O3-2 nanofiber sensors hold great prospect in the application of portable and room-temperature ppb NO2 detection equipment.