The enhanced n-butanol sensing performance of In2O3 loaded NiO cuboid heterostructure

Monitoring volatile organic compounds (VOCs) quickly and on-site is essential for preserving human health. The semiconductor gas sensor has been a promising strategy for detecting VOCs. However, stability, selectivity, and sensitivity are crucial for the practical application of a gas-sensor material. Innovative synthetic methods have been studied to improve the properties of sensor materials, such as better detection and stability and the construction of p-n heterojunction materials. In this work, NiO/In2O3 heterostructure was synthesized by fast microwave-assisted solvothermal (MAS) using nickel foam and indium nitrate and was studied as a gas sensor for detecting several VOCs. NiO/In2O3 has the combined properties of NiO, a ptype material, and of In2O3, an n-type. NiO/In2O3 presented a superior performance for detecting n-butanol at the ideal operating temperature (350 degrees C), with a fast response (6 s), good selectivity, and stability. The nButanol response at 100 ppm was R-a/R-g = 412 +/- 16, and a linear detection range from 1 to 200 ppm was achieved. The best sensing response for this material towards n-butanol is attributed to the electron depletion layer caused by NiO/In2O3 junction and more adsorption sites obtained during fast MAS synthesis. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Monitoring VOCs is crucial for human health, and semiconductor gas sensors are a promising strategy for detection. This study synthesized NiO/In2O3 heterostructure using innovative methods and investigated its performance as a gas sensor for detecting VOCs. NiO/In2O3 showed superior selectivity, stability, and sensitivity in detecting n-butanol due to the p-n heterojunction and increased adsorption sites.