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Two-dimensional (2D) nanostructures are attractive candidates for electrocatalytic applications owing to their excellent mechanical flexibility and large exposed surfaces. In this work, we present ultra-thin 2D NiO porous nanosheets prepared by a simple, economical and green experimental method (hydrothermal, freeze-drying, and sintering) as efficient electrocatalysts for direct methanol fuel cell (DMFC) application. Benefiting from the ultra-thin 2D framework and porous nanostructure, the 550-NiO catalyst (annealed at 550 °C) exhibit higher current density (12.54mA cm−2) and faster charge transfer in the catalytic process, due to its abundant solid state redox couples (Ni2+/Ni3+= 0.991), suitable oxygen defects and surface coverage of redox species (2.90 × 10−7mol cm−2). First-principles density functional theory calculations were employed to provide mechanistic insights into the methanol oxidation reaction over the NiO catalyst via methanol dehydrogenation to CO involving O–H and C–H bond scissions, and subsequently, CHO oxidation with OH. The most plausible reaction pathway of methanol oxidation on NiO (100) is predicted to be CH3OH → CH3O → CH2O → CHO → CHOOH → COOH → CO2. The reported facile, simple, low-cost and method provides an avenue for the rational design and synthesis of 2D NiO porous nanostructured electrode materials for DMFC and beyond.

In this paper, we report a hierarchical structure Ni(OH) 2 nanosheet array electrode by a directed liquid-phase approach, which consists of amorphous Ni(OH) 2 interface layer and crystalline ultra-thin porous Ni(OH) 2 nanosheets top layer. The testing results present that the maximum discharge capacity of 404.8 mA h g −1 at lower rate of 1.4 A g −1 and the ultra-high capacity of 1714 F g −1 at super-high rate of 50 A g −1 without decay after 3000 cycles was obtained, respectively. This unique design provides excellent flexibility, long and stable cycle lifetimes, high energy and power densities simultaneously.

Synroc is recognized as the second generation waste form for the disposal of high-level radioactive waste (HLW). In this research, one of the mostly studied Synroc minerals, zirconolite (CaZrTi2O7), was prepared by self-propagating high-temperature synthesis (SHS). CuO and MoO3 were employed as the oxidants with Ti as the reductant. Different TiO2/Ti ratios were selected to investigate reactivity and adiabatic temperature (Tad) of the designed SHS reactions. Zirconolite was successfully synthesized as the main phase at varied TiO2/Ti ratios using CuO and MoO3 as the oxidants. The as-synthesized samples were readily solidified with desirable density and Vickers hardness.

High yield of β-Ni(OH)2 was synthesized by hydrothermal reaction. After heat treatment, novel NiO nanosheets with hexagonal nanopores were obtained. Transmission electron microscopy was employed to investigate the morphology and the crystallographic structure of the products, which indicated that the nanosheets were commonly ⟨111⟩ orientated and the nanopores were bounded by {111} and {100} planes. Meanwhile, the nanosheets were oxygen-sufficient based on the electron energy loss spectroscopy. The mechanism associated with formation of the hexagonal nanopores was discussed according to structural evolution. This unique morphology and the chemical characteristics were considered as the probable key factor responsible for its excellent performance on catalysis, gas sense, and adsorption.

One-dimensional SrSn(OH) 6 nanowires were successfully synthesized through a rapid simple method-sonochemical synthesis at room temperature without using any templates or surfactants. The growth mechanism has been proposed, and the reaction conditions were carefully investigated. The experimental results revealed that both the ultrasound irradiation and the presence of Na 2 CO 3 in the synthetic process had an impact on the fast formation of the SrSn(OH) 6 nanowires. Moreover, a subsequent precipitation-hydrothermal treatment of SrSn(OH) 6 nanowires-was conducted in ethanol at 180 °C for 8 h in order to improve their crystallinity and thermal stalibity. SrSnO 3 nanorods were converted by calcination of the hydrothermally treated SrSn(OH) 6 nanowires at 700 °C for 3 h in air. In particular, it was the first attempt to test the electrochemical properties of the SrSnO 3 products as anode in a Li ion battery. The resulting SrSnO 3 nanorods exhibited a better cyclability over 50 cycles with a reversible lithium storage capacity of 200 mA h g ―1 than that of SrSnO 3 nanoparticles.

Uniform crystalline MgSn(OH) 6 nanocubes were synthesized by a hydrothermal method. The influences of reaction conditions were investigated and the results showed that the solvent constituents significantly affected the shape and size of MgSn(OH) 6 ·SnO 2 /Mg 2 SnO 4 has been obtained by thermal treatment at 850 °C for 8 h under a nitrogen atmosphere using MgSn(OH) 6 as the precursor. The electrochemical tests of SnO 2 /Mg 2 SnO 4 revealed that SnO 2 /Mg 2 SnO 4 has a higher capacity and better cyclability compared to pure SnO 2 or Mg 2 SnO 4 . The electrochemical performance of SnO 2 /Mg 2 SnO 4 was sensitive to the size of the nanoparticles. The lithium-driven structural and morphological changes of the electrode after cycling were also studied by the ex-situ XRD pattern and TEM tests. This work indicates that SnO 2 /Mg 2 SnO 4 is a promising anode material candidate for application in Li-ion batteries.

Nickel hydroxyl sulfate (Ni(SO4)0.3(OH)1.4) nanobelts were obtained via a simple template-free hydrothermal reaction. The structural evolution of Ni(SO4)0.3(OH)1.4 nanobelts during ex situ heat treatment and in situ electron irradiation are investigated using transmission electron microscopy (TEM) techniques mainly including bright-field imaging, selected-area electron diffraction combined with kinematic simulations, and high-resolution TEM. The transformation from Ni(SO4)0.3(OH)1.4 to NiO can be observed in both ex situ and in situ experiments. Based on the TEM results, the structural evolution is clarified and the preliminary structural framework of Ni(SO4)0.3(OH)1.4 is proposed. This structural evolution also provides an excellent approach for large-scale production and/or modification of NiO nanoparticles.

Low-dimensional single-crystalline CdCO3 nanostructures such as nanowires, nanobelts, nanorolls, and one-dimensional (1D) hierarchical structures have been synthesized through a convenient, low-temperature hydrothermal method, and the products have been characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and selected area electronic diffraction. The influences of ammonia concentration, reaction time, and temperature on the morphologies of CdCO3 have been investigated. In addition, these low-dimensional nanostructures can be transformed into oriented CdO nanoporous structures through heat treatment processing, and the corresponding shapes can be preserved completely.

In this paper, large-scale, single-crystalline ZnO nanotube arrays were directly fabricated onto F-doped SnO2 (TCO) glass substrate via an electrochemical deposition method from an aqueous solution for the first time. The tubes had a preferential orientation along the [0001] direction and hexagon-shaped cross sections. The novel nanostructure could be easily fabricated without a prepared layer of seeds on the substrate. The surface condition of substrate material and the experimental conditions played a key role in the nanotube formation. A possible formation mechanism has been proposed. Keywords: ZnO nanotube, Arrays, TCO glass, Electrochemical deposition

Nanobelts of nickel hydroxyl sulfate have been prepared on a large scale via a simple template-free hydrothermal reaction on the basis of a complex [Ni(NH(3))(6)](2+) formed with Ni(2+) and ammonia in an ethanol-water solution. The as-synthesized nanobelts were single crystals, with several tens of microns in length and 50-150 nm in width. The nanobelts were enclosed by top surfaces (100) and side surfaces (001) and their growth direction was parallel to [010]. The function of aqueous ammonia and ethanol was discussed. Furthermore, nanostructures of a mixture of crystralline NiO and amorphous nickel sulfate with various morphologies, such as nanobelts, porous nanobelts, and nanoparticles, were obtained by the thermal treatment of the as-synthesized Ni(SO(4))(0.3)(OH)(1.4) nanobelts at different temperatures.

One-dimensional SrSn(OH) 6 nanowires were successfully synthesized through a rapid simple methods sonochemical synthesis at room temperature without using any templates or surfactants. The growth mechanism has been proposed, and the reaction conditions were carefully investigated. The experimental results revealed that both the ultrasound irradiation and the presence of Na 2 CO 3 in the synthetic process had an impact on the fast formation of the SrSn(OH) 6 nanowires. Moreover, a subsequent precipitations hydrothermal treatment of SrSn(OH) 6 nanowiresswas conducted in ethanol at 180 °C for 8 h in order to improve their crystallinity and thermal stalibity. SrSnO 3 nanorods were converted by calcination of the hydrothermally treated SrSn(OH) 6 nanowires at 700°C for 3 h in air. In particular, it was the attempt to test the electrochemical properties of the SrSnO 3 products as anode in a Li ion battery. The resulting SrSnO 3 nanorods exhibited a better cyclability over 50 cycles with a reversible lithium storage capacity of 200 mA h g−1 than that of SrSnO 3 nanoparticles.

This paper describes a facile solvothermal method to synthesize self-assembled three-dimensional (3D) Ni2+-Fe3+ layered double hydroxides (LDHs) nanocrystals. Flower-like Ni2+-Fe3+ LDHs constructed of thin nanopetals were obtained using ethylene glycol (EG) as a chelating reagent and urea as a hydrolysis agent. The reaction mechanism and self-assembly process are discussed. After calcinating the as-prepared LDHs at 450 °C in nitrogen gas, porous NiO/NiFe 2 O 4 nanosheets were obtained. This work resulted in the development of a simple, cheap, and effective route for the fabrication of large area Ni2+-Fe3+ LDHs as well as porous NiO/NiFe 2 O 4 nanosheets.

In this paper, single-crystalline Ni(SO4)0.3(OH)1.4 nanocrystals could be synthesized on a large scale by a facile hydrothermal treatment without using templates or organic additives. Ammonia concentration played an important role for the composition, phase structure and shape control of the the Ni(SO4)0.3(OH)1.4 nanobelts. Electrochemical measurement revealed that the asprepared Ni(SO4)0.3(OH)1.4 nanobelts exhibited high specific capacity close to the theoretical capacity performance of β-Ni(OH)2. On the other hand, the single-crystalline porous nickel oxide nanobeltsnanobelts can be obtained through calcination of the Ni(SO4)0.3(OH)1.4. nanobelts.

This paper describes a facile solvothermal method to synthesize self-assembled three-dimensional (3D) Ni2+-Fe3+ layered double hydroxides (LDHs). Flower-like Ni2+-Fe3+ LDHs constructed of thin nanopetals were obtained using ethylene glycol (EG) as a chelating reagent and urea as a hydrolysis agent. The reaction mechanism and self-assembly process are discussed. After calcinating the as-prepared LDHs at 450 degrees C in nitrogen gas, porous NiO/NiFe2O4 nanosheets were obtained. This work resulted in the development of a simple, cheap, and effective route for the fabrication of large area Ni2+-Fe3+ LDHs as well as porous NiO/NiFe2O4 nanosheets.