Humidity sensing properties of Ni(OH)2 nanoparticles synthesized via sonochemical method

•Nickel hydroxide nanoparticle was synthesized via the sonochemical method.•Humidity sensing properties of nickel hydroxide nanoparticle were investigated.•Having a response time smaller than 4 s and showing a near-linear response to the humidity, nickel hydroxide nanoparticle sensor has a good performance.

This work focuses on humidity sensor based Ni(OH)2 nanoparticles. The sonochemical method was employed to prepare nanoparticles and impedance analysis was used to characterize sensitivity, response, and recovery time of the prepared sensor. The Ni(OH)2 sensor was found to have high sensitivity and fast response/recovery time to humidity, and its impedance changed approximately two orders of magnitude from about 2.01 MΩ in dry air 20% RH (relative humidity) to 0.0258 MΩ in 90% RH air. Our results demonstrate the potential application of Ni(OH)2 nanoparticles for fabricating high performance humidity sensors.