Synergy between Au and In2O3 microspheres: A superior hybrid structure for the selective and sensitive detection of triethylamine

Design of metal/semiconductor hybrid nanostructures provides an important strategy for developing efficient chemical gas sensors. Herein, a highly sensitive gas sensing material for detection of triethylamine is designed by loading Au nanoparticles on porous In2O3 microspheres. The In2O3 microspheres are prepared by thermally annealing the precursor of 3D nanosheets assembled In2S3 microspheres. Then, Au nanoparticles are functionalized onto In2O3 to obtain a novel Au/In2O3 hybrid microspheres. The morphological structure and chemical composition of the prepared materials were studied in detail by different techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The gas sensing properties of the Au/In2O3 microspheres have been systematically investigated. Results reveal that the amount of Au has a large influence on the sensor performances. The Au/In2O3 sensor with Au content of 0.53 at. % exhibits the best response to triethylamine at 280 degrees C. An extremely high response of 648.2 is registered on exposure to 100 ppm triethylamine. The sensor also possess fast response-recovery and very stability, as well as a low detection limit of 108 ppb. The sensing mechanism behind the enhanced sensor performances are also discussed.