Monodisperse Fe3O4 nanocubes have been successfully synthesized by a facile solvothermal method at 260 °C in the presence of oleic acid and oleylamine. Well-defined assembly of uniform Fe3O4 nanocubes with an average size of 12 nm could be obtained without a size-selection process. The shape of as-prepared Fe3O4 nanoparticles could be reversibly interchanged between spheres and cubes by adjusting the reaction parameters. The phase structures, morphologies, and sizes of as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The magnetic properties of Fe3O4 nanocubes were measured by using a quantum design superconducting quantum interference device (SQUID). The magnetic study reveals that the as-synthesized nanocubes are ferromagnetic at 2 K while they are superparamagnetic at 300 K.

To reveal the impact of mining on bacterial ecology around mining area, bacterial community and geochemical characteristics about Dabaoshan Mine (Guangdong Province, China) were studied. By amplified ribosomal DNA restriction analysis and phylogenetic analysis, it is found that mining pollution greatly impacts the bacterial ecology and makes the habitat type of polluted environments close to acid mine drainage (AMD) ecology. The polluted environment is acidified so greatly that neutrophil and alkaliphilic microbes are massively dead and decomposed. It provided organic matters that can make Acidiphilium sp. rapidly grow and become the most bacterial species in this niche. Furthermore, Acidithiobacillus ferrooxidans and Leptospirillum sp. are also present in this niche. The amount of Leptospirillum sp. is far more than that of Acidithiobacillus ferrooxidans, which indicates that the concentration of toxic ions is very high. The conclusions of biogeochemical analysis and microbiological monitor are identical. Moreover, because the growth of Acidithiobacillus ferrooxidans and Leptospirillum sp. depends on ferrous iron or inorganic redox sulfur compounds which can be supplied by continual AMD, their presence indicates that AMD still flows into the site. And the area is closer to the outfalls of AMD, their biomasses would be more. So the distinction of their biomasses among different areas can help us to find the effluent route of AMD.

Size-controlled Fe3O4 nanoparticles were prepared via a facile solvothermal method by using the mixed surfactants of SDS and PEG as protective reagents. The sizes of the nanoparticles can be varied from 15 to 190 nm by adjusting the experimental conditions. The influences of the protective reagents, reaction time, the initial concentration of the reactant, molar ratio of FeCl3 and protective reagents on the size of the produced nanoparticles were studied. The size and morphology of the products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and scanning electron microscopy (SEM).

An in situ polymerization route has been developed to synthesize SiO2/polypyrrole core–shell particles and polypyrrole hollow spheres with controllable shell thickness. In this process, pyrrole monomers adsorbed on the surface of SiO2 spheres due to electrostatic interactions, SiO2/polypyrrole core–shell particles could be subsequently obtained in large quantities via in situ polymerization under hydrothermal conditions. Furthermore, polypyrrole hollow spheres could be obtained after the removal of the core via HF etched method. The shell thickness of core–shell particles and hollow spheres could be easily controlled by adjusting the process parameters such as monomer concentration and hydrothermal temperature. The morphology, size and structure of the final products were investigated in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier-transform infrared spectra (FTIR). The probable formation mechanism of core–shell particles and hollow spheres was proposed on the basis of the experimental results.

Monodisperse Zn ferrite nanospheres and its Ba substitution nanosheets were successfully prepared by a facile solvothermal method. The size, morphology, and structure of the as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Magnetic studies revealed that Zn ferrite nanospheres are ferrimagnetic with a saturation magnetization (Ms)(Ms) of 49.6 emu /g and MsMs increased from 49.6 emu /g to 84.2 emu /g when Ba2+ was substituted into Zn ferrite to form BaZn ferrite nanosheets. To explain the variations of morphology and magnetic properties, the strong preferential occupancy of cations in chemically equivalent A and B sites and the metastable cation distribution in nanoparticles are invoked.

Single-crystalline yttrium hydroxide nanotubes could be successfully synthesized in large quantities via a metastable nanosheet precursor reacted with sodium hydroxide under hydrothermal conditions. The nanosheet precursors were obtained through a facile hydrothermal synthetic method using soluble yttrium nitrate as the yttrium source and triethylamine as both an alkaline and complexing reagent. The influences of reaction time and concentration of sodium hydroxide on the formation of yttrium hydroxide nanotubes were investigated. Yttrium oxide and europium-doped yttrium oxide nanosheets and nanotubes could also be selectively obtained via a thermal decomposition method using the corresponding hydroxides as precursor. The phase structures, morphologies, and properties of the as-prepared products were investigated in detail by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), high-resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopies. The formation mechanisms of yttrium hydroxide nanotubes were discussed based on the experimental results. These low-dimensional nanostructures could be expected to bring new opportunities in the vast research and application areas.

Monodisperse Zn ferrite hollow nanospheres and nanosheets could be selectively synthesized via a facile solvothermal method. The shape, structure and size of Zn ferrites were investigated by XRD, TEM, SEM, and HRTEM. The magnetic and microwave absorption properties of hollow Zn ferrite nanospheres and nanosheets were also investigated in detail. Magnetic studies revealed that both the saturation magnetization (Ms) and coercivity (Hc) of hollow nanospheres are drastically higher than those of nanosheets. Electromagnetic and resulting microwave adsorption properties showed that hollow nanospheres have four dips and the maximum magnitudes of the dips is −31.44 dB at 10.48 GHz. The probable formation mechanism of hollow nanospheres was discussed on the basis of the experimental results.

Uniform single-crystalline indium hydroxide microcubes can be successfully synthesized in large quantities via a convenient hydrothermal route using hydrated indium nitrate and sodium borohydride as reagents under mild conditions. The morphology and size of indium hydroxide microcubes can be controlled by varying the synthetic parameters such as hydrothermal time, reaction temperature, and surfactant. Single-crystalline indium oxide microcubes also can be successfully prepared by a thermal decomposition method using indium hydroxide microcubes as the precursor. The phase structures, morphologies, and optical properties of the final products were investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetric analysis, thermogravimetric analysis, and photoluminescence spectroscopy. These uniform single-crystalline microcubes may be useful in microelectronic and optoelectronic devices.

Single-crystalline gallium oxide hydroxide (α-GaOOH) nanorods could be successfully synthesized in large quantities through a hydrothermal synthetic method using gallium oxide as the gallium source and sodium azide and aqueous hydrazine as both alkaline and complexing reagent. Single-crystalline gallium oxide (α-Ga2O3 and β-Ga2O3) nanorods could be selectively obtained by thermal decomposition method using gallium oxide hydroxide nanorods as the precursor. The phase structures, morphologies and properties of the final products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), fourier transform infrared spectra (FTIR), differential scanning calorimetric analysis (DSC), thermogravimetric analysis (TG), and photoluminescence spectra (PL).

Round-biscuit-like Fe3O4 nanoparticles were successfully prepared in large-scale by a simple solvothermal method. The sizes of the particles can be readily tuned from 15 to 150 nm by adjusting the experimental parameters such as solvothermal temperature, reaction time, the initial concentration of the reactants, and molar ratio of FeCl3 and protective reagents. Structure, morphology and size products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and scanning electron microscopy (SEM). Magnetic studies revealed that the saturation magnetization (Ms)(Ms) increases as the particle size increases.

Monodisperse Zn ferrite nanospheres and its Ba substitution nanosheets were successfully prepared by a facile solvothermal method. The size, morphology, and structure of the as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Magnetic studies revealed that Zn ferrite nanospheres are ferrimagnetic with a saturation magnetization (Ms) of 49.6 emu /g and Ms increased from 49.6 emu /g to 84.2 emu /g when Ba2+ was substituted into Zn ferrite to form BaZn ferrite nanosheets. To explain the variations of morphology and magnetic properties, the strong preferential occupancy of cations in chemically equivalent A and B sites and the metastable cation distribution in nanoparticles are invoked.