Sonochemical synthesis, size controlling and gas sensing properties of NiO nanoparticles

▶ In this work, we synthesized NiO Nano-sized particles (NiO-NP) by using a simple sonochemical method for the preparation of NiO nanoparticles directly without any additive from nickel acetate solutions. ▶ NiO-NP based chemoresistive gas sensors were realized and gas sensing tests towards NO2 and CO were performed, showing promising results compared with the NiO thin films gas sensors. ▶ The gas sensing tests on resulting devices show remarkable response to NO2 even at very low operating temperatures and good responses towards CO. ▶ This result is attributed to the preparation of highly Nano-sized oxide particles and to their processing for the device realization. In fact, the final sensing layer results a porous and not sintered structure resulting in extensive interaction with the gases. ▶ The results obtained are very promising and stimulating and in further developing of NiO-NP based sensor devices.