Hydrothermal synthesis of novel flower-needle NiO architectures: Structure, growth and gas response

Self-assembly of one-dimensional nanoscale building blocks into functional three-dimensional superstructures has attracted vast interests. In current work, novel NiO flower-like architectures have been successfully synthesized via a facile hydrothermal method and subsequent calcination. Notably, it has been observed that the sodium oxalate plays a vital role on the aggregation of needles and a novel growth mechanism of needle-flower NiO has been proposed in detail based on the experimental results. More importantly, it is noted that the gas sensing properties of the flower-like architectures are superior to needle-like structures on the basis of the investigation. Such a synthetic way may open up an avenue to tailor the morphologies of some other metal oxides and enhance their gas sensing performance. (C) 2015 Elsevier B.V. All rights reserved.