In-situ growth of hierarchical SnO2/In2O3 heterostructures with multiple effective n-n heterojunctions for superior triethylamine-sensing performances

Abstract

In this paper, hierarchical and porous SnO2/In2O3 heterostructures with tunable nanoparticles in-situ growth on the surface of matrix fibers are successfully fabricated by a facile one-step electrospinning technology. Gas-sensing performances of different samples under the absence or presence of UV light irradiation have been systematically investigated for estimating the unique surface/interface transmission characteristics of SnO2-based sensors and their potential application. For example, SnO2/In2O3 composites with poor gas selectivity exhibit a high optimal working temperature of 300 °C under the normal condition. However, the optimal working temperature can be significantly decreased from 300 to 90 °C after introducing UV light irradiation with a power of 120 mW/cm2, together with the high response of 6.47, the low detection limit of 1.07 ppm, and the excellent gas selectivity for triethylamine (TEA). In addition, these novel hierarchical structures can be employed for the practical application of seafood freshness evaluation by detecting the gas released during the storage of prawns. The enhanced gas-sensing properties of SnO2/In2O3 composites can be ascribed from the combination of the accelerated electron migration and absorption/desorption process, multiple effective n-n heterojunctions, and the unique microstructures under UV light irradiation.