Evolution of In2O3 morphology from belt to fibrous-like structure for ethanol detection at low working temperature induced by Cr-addition

Herein, a high-performance ethanol functional nanosensor based on Cr-doped In2O3 nanofibers was produced via a one-step electrospinning method followed by annealing at 700 & DEG;C. The combination of several systematic techniques showed that incorporation of Cr-dopant ions into In2O3 host lattice can effectively improve ethanol sensing capabilities of In2O3 nanofibers by reducing the operating temperature from 100 to 80 & DEG;C, inducing additional oxygen vacancies, and increasing the content of chemisorbed oxygen ions at various Cr-doping levels. A comparison of the gas sensing performance findings of sensors based on the pure and Cr-doped In2O3 nano -fibers at different doping levels of 0.5, 1, 1.5 mol% revealed that all Cr-doped sensors presented a high response and selectivity towards 50 ppm ethanol at 80 & DEG;C with a 1 mol% Cr-doped In2O3 sensor displaying the highest response of 12 which is 10 times higher than that of the pure In2O3 sensor. Furthermore, the response/recovery times of the 1 mol% Cr-doped In2O3 towards 50 ppm ethanol were 41/43 s while the minimum detection limit value was 2.19 ppm. With such rapid response kinetics, low detection limit, moisture resistant, Cr-doped sensors can be a promising active sensing layer for monitoring ethanol in real food environments.

Automated summary

A high-performance ethanol functional nanosensor based on Cr-doped In2O3 nanofibers was prepared, which showed improved ethanol sensing capabilities. The response and selectivity of the Cr-doped sensors towards 50 ppm ethanol at 80℃ were significantly higher compared to the pure In2O3 sensor. The 1 mol% Cr-doped In2O3 sensor exhibited the highest response of 12, 10 times higher than the pure In2O3 sensor, with fast response kinetics and a low detection limit of 2.19 ppm.