Formation of Nickel Oxide Nanotubes with Uniform Wall Thickness by Low‐Temperature Thermal Oxidation Through Understanding the Limiting Effect of Vacancy Diffusion and the Kirkendall Phenomenon

Abstract

In this work, the step-wise oxidation mechanism of nickel (Ni) nanowires is elucidated. Rapid vacancy diffusion plays a signifi cant role at low temperatures in forming heterostructures of nickel oxide (NiO) nanotubes with Ni nanowires. Subsequent investigations of Ni nanowire oxidation at higher temperatures and faster temperature ramp rates show that it is diffi cult to bypass this rapid vacancy diffusion stage, which affects the formation of the fi nal structure. Therefore, it is unlikely to form solid NiO nanowires or NiO nanotubes with uniform wall thickness through the conventional annealing/ oxidation process of Ni nanowires. Instead, a step-wise oxidation process by combining low temperature oxidation with a chemical etching step is utilized to produce for the fi rst time NiO nanotubes with uniform wall thickness from Ni nanowires.

An efficient methodology for measurement of the average electrical properties of single one-dimensional NiO nanorods

“…For example, nickel oxide nanostructures possess various outstanding properties, such as a wide bandgap (~3.88 eV)2, large specific capacitance (~390 F/g)3 for supercapacitor electrodes, high-performance discharge capacity (~638 mA h/g)4 for lithium ion batteries, high carrier density (~7.35 × 10 18  cm −3 )5, rapid switching time (<10 ns)6 for resistance-based memory, stable endurance (up to 1 × 10 6 cycles)7 for resistive switching, high photon-to-current conversion efficiency (~45%) for sandwich dye-sensitized solar cells8, high catalytic activity (42.3 gm −2 ) for carbon-monoxide oxidation9, very fast coloration and bleaching times (1.55 and 1.22 s)10 for electrochromic devices, and so on. NiO nanostructures can be fabricated in a variety of forms including nanowalls24, nanoslices3, nanoplates3, nanoparticles5, nanofilaments6, nanowires711, nanocolumns39, nanotubes1112, and nanorods1113. However, one-dimensional (1D) nanostructures like nanowires and nanorods are more suitable than the other zero- and two-dimensional nanostructures for applications in electronic nanodevices.…”

“…Vertical-aligned 1D NiO nanorod (or nanowire) arrays are difficult to synthesize by conventional chemical reaction2378911 and thermal oxidation deposition techniques451213. In this study, we are able to synthesize large-area arrays of vertical-aligned 1D NiO nanorods using the hot-filament metal-oxide vapor deposition (HFMOVD) technique.…”

Electrochemical synthesis and magnetism of magnetic nanotubes

“…NTs can also be formed by wetting process of template with a solution containing the precursor material, followed by thermal decomposition of the precursor to obtain nanocrystalline metallic NTs (Steinhart et al, 2003;Nielsch et al, 2005a,b). The Kirkendall effect, a classical phenomenon in metallurgy, was also recently applied to synthesize hollow nanostructures (Fan et al, 2007a,b;Ren et al, 2010). The Kirkendall effect, a classical phenomenon in metallurgy, was also recently applied to synthesize hollow nanostructures (Fan et al, 2007a,b;Ren et al, 2010).…”

Attachment of nickel oxide nanoparticles on the surface of palygorskite nanofibers

“…Meanwhile, many efforts have also been focused on the effective control of NiO particle size and shape, such as single-crystalline nanowire arrays [12], nanotubes [13], hollow nanospheres [15,16], nanosheets [11], films [17], ordered mesoporous solids [18], and other morphologies [19]. The advent of nanostructured support materials such as carbon nanofibers, carbon nanotubes, nano-fibriform silica, and ordered mesoporous silica has provided opportunities for the novel supported metal oxide catalysts, which were indispensable for energy and chemical industries to reduce consumption of raw materials and to minimize the production of waste [20].…”

“…Recently, there were reports about the successful synthesis of nanosized NiO via metal-etching oxidation [12], low temperature thermal oxidation [13], and fibrinogen template method [14].…”