Synthesis of ZnO‐CuO Nanocomposite Aerogels by the Sol‐Gel Route

Abstract

The epoxide addition sol-gel method has been utilized to synthesize porous zinc-copper composite aerogels in the zinc-to-copper molar ratios of 50 : 50 to 90 : 10. A two-step mixing approach has been employed to produce aerogels composed of nano- to micrometer sized particles. The aerogels were characterized by ultrahigh resolution scanning electron microscopy, transmission electron microscopy, and powder X-ray diffraction. The as-synthesized aerogels had a thin flake- or petal-like microstructure comprised of clustered flakes on two size scales; they were identified as being crystalline with the crystalline species identified as copper nitrate hydroxide, zinc hydroxide chloride hydrate, and zinc hydroxide nitrate hydrate. Annealing of the aerogel materials at a relatively low temperature (400°C) resulted in a complete phase transition of the material to give highly crystalline ZnO-CuO aerogels; the aerogels consisted of networked nanoparticles in the ~25–550 nm size range with an average crystallite size of ~3 nm and average crystallinity of 98%. ZnO-CuO aerogels are of particular interest due to their particular catalytic and sensing properties. This work emphasizes the versatility of this sol-gel route in synthesizing aerogels; this method offers a possible route for the fabrication of aerogels of different metal oxides and their composites.

Moisture sensing studies of CuO‐ZnO nanocomposites

“…Various methods/techniques, for example, hydrothermal, sol‐gel, precipitation, electrochemical , and microwave‐assisted method are reported to synthesize nanocomposite material in bulk. In the present study, the CuO–ZnO nanocomposite samples with different wt% (0.2, 0.4, 0.6, 0.8, and 1) of CuO were successfully prepared through solid‐state reaction route.…”

“…13 In general, combination of narrow band gap semiconductors with wide band gap semiconductors will increase their sensing property. [14][15][16][17] These nanocomposites are already used in several applications such as solar cells, 18 gas sensors, 19 biosensors, 20 and humidity sensors. 21 These reported nanocomposite materials also showed various nanostructural morphologies, eg nano-rings, nano-combs, nano-belts, nano-tubes, nano-rods, and nano-sheets.…”

Photo-assisted mineralisation of titan yellow dye using ZnO nanorods synthesised via environmental benign route

“…ZNRs are conventionally synthesized via chemical methods like precipitation, chemical vapour deposition, hydrothermal, solution combustion, sol-gel, sono and electrochemical methods [1,[29][30][31] which are actually not recommended in green chemistry. Biological approaches for synthesis of metal oxide nano particles have been suggested as valuable and eco-friendly alternatives to chemical methods [7].…”

Synthesis of ZnO-CuO flower-like hetero-nanostructures as volatile organic compounds (VOCs) sensor at room temperature

“…It is n-type wide band gap semiconductor (3.37 eV), with a large excited binding energy (60 meV), good photochemical properties, nontoxic and inexpensive. Zinc oxide (ZnO) nanostructures are of particular interest for many applications, such as sensors, catalysts, field emitters and solar cells [9,10]. As another important semiconductor metal oxide, copper oxide (CuO) is a kind of intrinsic p-type semiconductor with a narrow band gap.…”