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Uniform ZnO nanospheres have been successfully synthesized through a facile solvothermal process. The structure and morphology of the products were characterized by powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the products were ZnO nanospheres of 300–350 nm in diameter, which were composed of nanoparticles of ca. 5–10 nm. The size of the nanospheres can be tuned from ca. 300 nm to 1 μm by changing the concentration of the reactants. The gas sensing performance of the ZnO nanospheres with different size were investigated, which indicated that the ZnO nanospheres exhibited good gas sensitivity and selectivity towards n-butanol. In addition, the gas sensitivity of the ZnO nanospheres exhibited obvious size-dependent effect. [ABSTRACT FROM AUTHOR]

Abstract: Uniform Cu2O nanoparticles have been successfully synthesized through a facile additive-free aqueous solution route at room temperature. The structure and morphology of the products were characterized by powder X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The results showed that the products were Cu2O nanocubes of 110–130nm in side length. The size of the nanocubes can be tuned from 20nm to 500nm by changing the concentration of the sodium hydroxide solution and the kind of copper salts. The visible-light photocatalytic properties of the as-obtained Cu2O products were investigated. The results showed that these Cu2O nanoparticles exhibited good photocatalytic activity towards methyl orange (MO). [Copyright &y& Elsevier]

Abstract: Hematite (α-Fe2O3) nanostructures with different morphologies have been synthesized by a simple ethylene glycol (EG)/H2O system using FeCl3 and urea as raw materials without adding any additives. Structure and morphology of the products were characterized by powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results indicated that the as-prepared samples are α-Fe2O3 microflowers, nanospindles, nanoparticles and nanorhombohedra. The magnetic properties and visible light photocatalytic properties of the products were investigated. The magnetic hysteresis measurements showed interesting magnetic property evolution among these α-Fe2O3 products, which can be attributed to their superstructure or the shape anisotropy. The photocatalytic measurements indicated that the α-Fe2O3 samples exhibit good photocatalytic property for Rhodamine B. [Copyright &y& Elsevier]

Abstract: Uniform copper hydroxyphosphate quadrangle star-like microcrystals with tunable size and microprism bundles have been achieved through a simple hydrothermal method. Reactions are conducted in a water system using CuSO4, NH4H2PO4 and NaOH as reactants without adding any surfactants. Structures and morphologies of the products were characterized by powder X-ray diffraction, scanning electron microscopy, fourier transform infrared spectrometry, and UV–vis spectrometry. It was found that the size and morphology of the products depended strongly on the concentration and the molar ratio of the starting reagents. The possible mechanism of the products was discussed and the size dependent photocatalytic property of the products was investigated. [Copyright &y& Elsevier]

Abstract: Uniform hematite nanoparticles have been successfully synthesized through a surfactant mediated hydrothermal method. The structure and morphology of the products were characterized by powder X-ray diffraction, transmission electron microscope, scanning electron microscope, and Fourier transform infrared spectrometer. The results showed that the products were α-Fe2O3 nanoellipsoids of 115–140nm in long axis and 60–80nm in short axis. The growth mechanism of the products was proposed based on the experiments. Uniform nanospindles, nanoellipsoids, nanospheres, and nanopolyhedra with different sizes can be obtained by adjusting the reaction temperature, the amount of additive, and concentration of the reactants. The result may facilitate the exploration of controlled synthesis of α-Fe2O3 nanoparticles. [Copyright &y& Elsevier]

Abstract: Single-crystal cuprous iodide semiconductor nanospheres were fabricated via a mild low-temperature solution route by using polyvinyl pyrrolidone as capping agent and the mixture of water and polyethylene glycol 400 as solvent. The structure, morphology, and properties of the products were characterized by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermal gravimetry and photoluminescence spectrometry. The results showed that the products were CuI nanospheres of ca. 280–650nm in diameter and were composed of quasi-trigonal particles of ca. 20–40nm. The phase transformation temperature and the melting point of the products decreased by ca. 12 and 8°C compared with the bulk CuI. The possible formation mechanism was discussed on the basis of experimental results. [Copyright &y& Elsevier]

Abstract: Nearly monodisperse Co3O4 nanospheres were fabricated via a facile polyethylene glycol 400-mediated solventhermal route followed by a calcination process at 500°C. The structure, morphology, and properties of the products were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and UV–vis spectrometry. The results showed that the products were Co3O4 nanospheres of 160–170nm in diameter and were composed of nanoparticles of ca. 40nm. The possible formation mechanism was discussed on the basis of experimental results. Furthermore, optical property of the products was characterized. [Copyright &y& Elsevier]

Abstract: Nanostructured CuO film was prepared using glass or stainless steel slices as substrate via a simple ammonia-assisted solution route at 60°C. The obtained CuO film was made up of well-crystallized nanosheets of 50–360nm in thickness and 0.7–4.5μm in width. The reaction time and the substrate have significant effects not only on the thickness, width, arrangement of the nanosheets but also on the morphology and the thickness of the films. The CuO film was characterized by SEM, TEM, XRD, IR, and Raman spectroscopy techniques. [Copyright &y& Elsevier]

Abstract: Single-crystalline cuprous iodide semiconductor nanorods were fabricated via a facile and efficient room-temperature solution process by using polyacrylamide (PAM) as a structure-directing agent, followed by heat treatment at 180 °C. The diameter and length of the nanorods were estimated to be ca. 50 nm and ca. 1 μm, respectively. And the phase-transformation temperature and decomposition temperature of the as-prepared CuI nanorods were deduced from the DSC curve of the products, which decreased markedly compared with those of the bulk CuI material. Moreover, a possible growth mechanism of the CuI nanorods based on polymer-crystal interactions in a mild aqueous solution is proposed. [Copyright &y& Elsevier]

• The NiFe 2 O 4 /NiO composite nanosheets with different Fe contents have been synthesized. • The composite sensors exhibited enhanced acetone gas sensing performances than pure NiO and NiFe 2 O 4. • The Fe/Ni-24.9 at% sensor reached the highest response value of 56.0 to 200 ppm of acetone. A series of NiFe 2 O 4 /NiO composites composed of NiFe 2 O 4 nanoparticles dispersing on NiO nanosheets were successfully prepared under solvothermal condition using NiO precursor and FeCl 3 ·6H 2 O. Gas-sensing performance assessment demonstrated the formation of composites can improve the properties effectively. The sensor based on sample Fe/Ni-24.9 at% exhibited the optimal gas-sensing performance, showing fast response/recovery, good repeatability and high response of ~23.0 to 50 ppm acetone at 280 °C, which was about 1.8 times and 2.2 times of the pristine NiO and NiFe 2 O 4. The excellent sensing performance can be ascribed to the p-p heterojunction between the NiO and NiFe 2 O 4 , which may decrease the charge carrier concentration in NiO near the heterojunction and bring about larger resistance variation upon the adsorption of target gas. [ABSTRACT FROM AUTHOR]

• Ag-doped ZnO/CdO ternary heterostructure have been synthesized. • The ternary composite exhibited enhanced HCHO sensing property at low temperature. • The AZC-2 sensor reached a high response value of 164 to 50 ppm HCHO at 150 °C. • A low experimental detection limit of 100 ppb can be achieved. • Both the Ag doping and multiple heterojunctions contribute to the property improvement. Novel Ag-doped ZnO/CdO ternary heterostructures (AZC composite) were fabricated and characterized by X-ray diffractometer (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and etc. The results showed that Ag nanoparticles were attached onto the ZnO/CdO surface and multiple heterojunctions including Ag/ZnO, Ag/CdO Schottky junctions and ZnO/CdO homo-type heterojunction were generated. The formaldehyde (HCHO)-sensing performance of the AZC composites was tested. Compared with the ZnO/CdO composite, the AZC composites demonstrated much higher response and faster response/recovery rate. In particular, the AZC sample with an Ag content of 3.04 wt% (AZC-2) exhibited a high response of 164 to 50 ppm HCHO at 150 °C, a ppb-level detection limit, and acceptable humidity resistance. This work illustrated that Ag nanoparticles is a promising candidate for improving the sensing property of transition metal oxide due to its catalytic sensitization effect and relatively low cost. [ABSTRACT FROM AUTHOR]

Abstract: Various ZnO architectures like novel flowerlike structures radially assembled by rods, nails or towers and novel radialized bundled tubular structures with diverse diameter in entire length were controllably synthesized with different amine precursors by a simple surfactant-free hydrothermal process. It suggests that diverse amine sources, which possibly have different hydroxyl ion releasing rate contributing to different reaction rates, probably play an importance role in controlling the assembly of different ZnO architectures, besides temperature and time. X-ray powder diffraction (XRD) results prove the ZnO belonging to wurtzite structure and room temperature photoluminescence (PL) demonstrates a high quality of the products. [Copyright &y& Elsevier]