Humidity Sensor Based on In(OH)₃ Nanoparticles

Indium hydroxide (In(OH) 3 ) nanoparticles were prepared with a size of ∼25–45 nm using the homogeneous precipitation method, and a humidity sensor was developed based on this material. The crystal phase and elements of In(OH) 3 were characterized and analyzed using X-ray diffraction and X-ray photoelectron spectroscopy. The morphology and specific surface area were determined using scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption (Brunauer–Emmett–Teller) measurements. Additionally, humidity sensing tests were conducted on In(OH) 3 . Owing to the unique porous structure of In(OH) 3, the fabricated In(OH) 3 humidity sensor exhibited excellent humidity sensitivity characteristics, with a wide humidity detection range (11–95%), comparatively excellent response/recovery time (14 s/204 s), high response (430.6), good stability, and high resolution with a minimum detection limit of 1% relative humidity. The humidity response of the In(OH) 3 humidity sensor was tested at different temperatures, indicating its potential for use in diverse environments such as cold storage and bathrooms. Notably, the low manufacturing cost of this sensor further enhances its appeal for widespread applications. This work provides a promising humidity sensing material for the manufacture of high-performance humidity sensors.