Facile hydrothermal synthesis of mesoporous In2O3 nanoparticles with superior formaldehyde-sensing properties

Highlights: • Mesoporous In₂O₃ nanoparticles were prepared by a facile hydrothermal method. • The morphology, microstructure, and formation mechanism were discussed. • Mesoporous In₂O₃ nanopaticles showed superior HCHO-sensing properties. Mesoporous In₂O₃ nanoparticles were successfully synthesized via a facile, template free, and low-cost hydrothermal method. Their morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal and thermogravimetry analysis (DSC-TG), and N₂ adsorption-desorption analyses. The results reveal that mesoporous In₂O₃ nanoparticles with a size range of 40–60 nm, possess plenty of pores, and average pore size is about 5 nm. Importantly, the mesoporous structure, large specific surface area, and small size endow the mesoporous In₂O₃ nanoparticles with highly sensing performance for formaldehyde detection. The response value to 10 ppm HCHO is 20 at an operating temperature of 280 °C, and the response and recovery time are 4 and 8 s, respectively. It is expected that the mesoporous In₂O₃ nanoparticles with large specific surface area and excellent sensing properties will become a promising functional material in monitoring and detecting formaldehyde.