rGO/ZnO nanorods/Cu based nanocomposite having flower shaped morphology: AC conductivity and humidity sensing response studies at room temperature

Humidity control is an important environmental concern in storage, transport, and preservation operations in agriculture, food, medical, and other industrial fields. In the present work, we prepared a nanocomposite having flower shaped morphology that consists of metal (Cu) nanoparticles, a metal oxide (ZnO nanorods), and reduced graphene oxide (rGO) with a one-pot synthesis method for the AC conductivity and Humidity sensing response studies at room temperature. The morphology of the nanocomposite was characterized by using XRD, SEM, EDX, and TEM analysis. Conduction in the nanocomposite due to the hopping mechanism was confirmed by studying the power law behavior of its AC conductivity. The nanocomposite shows a maximum sensing response of 97.79% in the range of 11–97% RH, with response and recovery times of 19 s and 42 s, respectively. The nanocomposite shows a low humidity hysteresis and stable humidity sensing ability. The possible humidity sensing mechanism is discussed in detail. Our results show that the nanocomposite having flower shaped morphology is an ideal candidate for building MEMS/NEMS humidity sensors.