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

Abstract

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//In 2 O 3 bicomponent nanofibers using a homemade V-type dual-channel electrospinning technique. Compared with as-electrospinning pure ZnO nanofibers and pure In 2 O 3 nanofibers, the ZnO//In 2 O 3 -2 composite nanofibers showed higher response and low detection line NO 2 at room temperature. The ZnO//In 2 O 3 -2 nanofibers have a maximum high response of 109.84 to 60 ppm of NO 2 at room temperature, which is about 8.44 times higher than that of the pure In 2 O 3 nanofibers. Moreover, the theoretical detection limit for NO 2 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//In 2 O 3 -2 nanofiber sensors hold great prospect in the application of portable and room-temperature ppb NO 2 detection equipment.

P–N Heterojunction formation: Metal Sulfide@Metal Oxide Chemiresistor for ppb H2S Detection from Exhaled Breath and Food Spoilage at Flexible Room Temperature

“…Therefore, when the In 2 O 3 @MoS 2 -2 sensor is exposed to H 2 S gas (as shown in Figure b), H 2 S molecules react with O 2 – to produce SO 2 and H 2 O while releasing electrons. The sensing equation (5) is as follows , During this process, the electrons are returned to the conduction band, leading to an increase in the semiconductor’s resistivity, thereby causing a decrease in resistance.…”