Amorphous RhOx decorated black indium oxide for rapid and flexible NO2 detection at room temperature

Abstract

This paper focuses on the preparation and characterization of a composite material made from rhodium oxide amorphous-decorated black indium oxide (RhOx/B-In2O3) for use in MEMS gas sensors. The sensors were utilized for the detection of NO2 gas at room temperature, and the results demonstrate that the RhOx/B-In2O3 sensor exhibits excellent gas selectivity, high response, and extremely short response/recovery times (8s/17s) to 5 ppm NO2 gas at room temperature. Additionally, a flexible NO2 gas sensor based on the optimized RhOx/B-In2O3 composite was fabricated to expand its application. One of the unique aspects of the RhOx/B-In2O3 material is the existence of defects, which allows for greater adsorption of NO2 gas. This feature contributes to the increased gas selectivity seen in the B-In2O3 material as compared with common In2O3. The chemical sensitization and electron-rich properties of amorphous RhOx further enhance the gas-sensing performance of the material by reducing the reaction activation energy and increasing surface-adsorbed oxygen. Overall, the results demonstrate the potential of the RhOx/B-In2O3 composite material for use in advanced gas-sensing technologies.