Functional nanoporous carbon nanosheets (CNSs) with high surface areas have been synthesized by the pyrolysis of simple organic–inorganic layered zinc hydroxide nanosheets. The synthesized CNSs with abundant hydroxyl groups display remarkable reactivity and the capability for in situ loading with ultrafine Ag NPs, which show excellent catalytic activity toward the reduction of 4-nitrophenol (4-NP) by NaBH4.

New pink organic–inorganic layered cobalt hydroxide nanofibers intercalated with benzoate ions [Co(OH)(C6H5COO)·H2O] have been synthesized by using cobalt nitrate and sodium benzoate as reactants in water with no addition of organic solvent or surfactant. The high-purity nanofibers are single-crystalline in nature and very uniform in size with a diameter of about 100 nm and variable lengths over a wide range from 200 μm down to 2 μm by simply adjusting reactant concentrations. The as-synthesized products are well-characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), fast Fourier transforms (FFT), X-ray diffraction (XRD), energy dispersive X-ray spectra (EDX), X-ray photoelectron spectra (XPS), elemental analysis (EA), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and UV–vis diffuse reflectance spectra (UV–vis). Our results demonstrate that the structure consists of octahedral cobalt layers and the benzoate anions, which are arranged in a bilayer due to the π–π stacking of small aromatics. The carboxylate groups of benzoate anions are coordinated to CoII ions in a strong bridging mode, which is the driving force for the anisotropic growth of nanofibers. When NaOH is added during the synthesis, green irregular shaped platelets are obtained, in which the carboxylate groups of benzoate anions are coordinated to the CoII ions in a unidentate fashion. Interestingly, the nanofibers exhibit a reversible transformation of the coordination geometry of the CoII ions between octahedral and pseudotetrahedral with a concomitant color change between pink and blue, which involves the loss and reuptake of unusual weakly coordinated water molecules without destroying the structure. This work offers a facile, cost-effective, and green strategy to rationally design and synthesize functional nanomaterials for future applications in catalysis, magnetism, gas storage or separation, and sensing technology.

•This is first time metal-doped ZnO nanostructures have been prepared from a single-source LDH precursor.•The morphologies of the resulting nanostructures as well as their corresponding optical properties can be readily controlled by varying the evaporation temperature.•The prepared pure Fe-doped ZnO nanorods and nanowires exhibiting unique optical properties rarely observed in the previously reported ZnO nanostructures.•This method is simple, effective and readily amenable to scale-up without requiring any metal catalysts/additives, or expensive equipment.In this article, we report a new way of preparing metal-doped ZnO nanostructures for the first time using layered double hydroxide (LDH) as single-source precursor. Fe-doped ZnO nanostructures have been successfully synthesized by thermal evaporating LDH containing Zn2+ and Fe3+ in a conventional tube furnace under atmospheric pressure without using any catalysts or additives. SEM and TEM images reveal that large scale and uniform nanorods and nanowires can be obtained by controlling evaporation temperature at 600 °C and 800 °C, respectively. XRD displays a clear shift of ZnO diffraction peaks which can be attributed to an efficient Fe doping in the ZnO lattice, and EDX reveals that the doping content of Fe in ZnO nanorods and nanowires are 0.20 % and 0.49%, respectively. The obtained Fe-doped ZnO nanostructures exhibit intense excitonic UV emission of ZnO and novel structured blue emissions of impurity levels arising from Fe doping. This study provides a simple, effective, and economic way for fabrication of metal-doped ZnO nanostrucutres which could have potential applications in optoelectronic devices.A large amount of uniform one-dimensional Fe-doped ZnO nanostructures with controllable morphologies and unique optical properties have been prepared via a simple thermal evaporation method at relatively low temperatures, for the first time, using layered double hydroxides as single-source precursor.

Uniform carbon nanotubes (CNTs) with high purity and surface functionality have been synthesized by one-step solid-state pyrolysis of a simple organic–inorganic layered double hydroxide (LDH) precursor. The prepared CNTs without any extra treatment exhibit very high performance in the removal of both organic dyes and toxic heavy metal ions.

CoFe/MgO nanocomposites have been prepared from single-source inorganic layered double hydroxide (LDH) precursors via a H2 gas-phase reduction; the metal composition can be freely manipulated by tailoring the molecular composition of the LDH precursors.

Highly ordered transparent composite films of CdS and layered double hydroxides (LDHs) have been fabricated using a template synthesis method; the size of the CdS particles in the LDH host can be controlled by adjusting the length of time of the reaction with H2S.

Europium complexes of ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA), [Eu(EDTA)(H2O)3]−, and [Eu(NTA)2(H2O)]3−, which have similar geometries but different charge densities, have been incorporated in Zn−Al layered double hydroxides (LDHs). The orientation and loading of the guest anions as well as their thermal stability and reorientation behavior are significantly influenced by their charge density. The maximal dimension of the [Eu(EDTA)(H2O)3]− anion is nearly perpendicular to the LDH layers and a reversible reorientation occurs on mild heating. The structural changes that occurred on heating were followed by variable temperature photoluminescence (PL) measurements. The kinetics of the structural transformation of ZnAl-Eu(EDTA) LDH in the temperature range 30−150 °C have also been studied. In the case of [Eu(NTA)2(H2O)]3−, the anion adopts a flat orientation in the interlayer galleries with its maximum dimension nearly parallel to the metal hydroxyl layers and no reorientation is observed on heating.

Large (~1 cm2) transparent highly (111)-oriented mesoporous self-supporting Ni–Al oxide films of uniform small nanoparticles have been prepared using an Ni2Al(OH)6(NO3)·2.1H2O layered double hydroxide (LDH) as a single precursor. The monodisperse small LDH nanoparticles (about 20 nm in diameter) are first cast as an oriented assembly on a glass substrate to form large transparent self-supporting (00l)-oriented LDH films. Subsequent heating in air affords (111)-oriented mesoporous Ni–Al oxide films preserving the shape, dimensions and optical transparency of the films. The process involves a topotactic transformation from the LDH (00l) facet to the NiO and NiAl2O4 spinel (111) facets, demonstrated here for the first time, and does not require any template, structure-directing agent, or lattice-matched single crystal substrate. The nanostructures of the resulting mixed metal oxide films can be controlled by changing the calcination temperature: Al-doped NiO and composite NiO/NiAl2O4 films of uniform small nanoparticles have been obtained at 500 °C and 900 °C respectively. The pore size and pore size distribution increase monotonically with temperature due to the increased sintering of the nanoparticles at higher temperatures. The resulting large transparent Ni–Al oxide films have a narrow distribution of mesopores (<10 nm) and high thermal stability, suggesting their potential application as catalysts or catalyst supports, in sensors, and as ultrafiltration membranes in harsh environments.

The nickel(II) citrate complex anion ([Ni(C6H4O7)]2−) may be intercalated into the interlayer galleries of a layered double hydroxide (LDH) host by a process involving ion-exchange with an Mg2Al–NO3 LDH precursor. The powder X-ray diffraction (XRD) pattern confirms that the layered structure is maintained. The thermal decomposition process of the complex anion-intercalated material has been characterized by in situ high temperature powder XRD, thermogravimetry-differential thermal analysis (TG-DTA) and coupled with mass spectrometry (MS). The thermal stability of the nickel(II) citrate complex anion intercalated in LDHs in air is lower than that in the sodium salt. Calcination generates a high degree of nickel(II) oxide dispersion in a matrix of magnesium and aluminium oxide phases which should be an advantage if the materials are used as catalyst precursors. Based on the observed data, a structural model for the [Ni(C6H4O7)]2− anion intercalated in the galleries of the LDH is proposed.

Large (~1 cm2) transparent highly (111)-oriented mesoporous self-supporting Ni–Al oxide films of uniform small nanoparticles have been prepared using an Ni2Al(OH)6(NO3)·2.1H2O layered double hydroxide (LDH) as a single precursor. The monodisperse small LDH nanoparticles (about 20 nm in diameter) are first cast as an oriented assembly on a glass substrate to form large transparent self-supporting (00l)-oriented LDH films. Subsequent heating in air affords (111)-oriented mesoporous Ni–Al oxide films preserving the shape, dimensions and optical transparency of the films. The process involves a topotactic transformation from the LDH (00l) facet to the NiO and NiAl2O4 spinel (111) facets, demonstrated here for the first time, and does not require any template, structure-directing agent, or lattice-matched single crystal substrate. The nanostructures of the resulting mixed metal oxide films can be controlled by changing the calcination temperature: Al-doped NiO and composite NiO/NiAl2O4 films of uniform small nanoparticles have been obtained at 500 °C and 900 °C respectively. The pore size and pore size distribution increase monotonically with temperature due to the increased sintering of the nanoparticles at higher temperatures. The resulting large transparent Ni–Al oxide films have a narrow distribution of mesopores (<10 nm) and high thermal stability, suggesting their potential application as catalysts or catalyst supports, in sensors, and as ultrafiltration membranes in harsh environments.

CoFe/MgO nanocomposites have been prepared from single-source inorganic layered double hydroxide (LDH) precursors via a H2 gas-phase reduction; the metal composition can be freely manipulated by tailoring the molecular composition of the LDH precursors.