Four separate coprecipitation routes were applied to the preparation of Ni x Mn1−x (OH)2 mixed hydroxides with x = 1, 5/6, 2/3, 1/2, 1/3, and 0, beginning with divalent nitrates. The structure and morphology of the samples were studied by X-ray diffraction and scanning electron microscopy techniques. Intentionally bubbled air during coprecipitation was found to create layered double hydroxide (LDH) phases for x = 5/6, coexisting LDH and Mn3O4 phases for 5/6 > x > 0, and Mn3O4 for x = 0. On the basis of the structures observed, these trends could be attributed to the relative ease of oxidation of Mn2+ to Mn3+. Pure hydroxides, with the expected Ni(OH)2 structure, were prepared for all x when air was excluded from the coprecipitation reaction. Spherical and dense particles could be prepared for all compositions attempted when ammonia was added during coprecipitation under anaerobic conditions.

CeO2 spherical crystallites aggregated by small CeO2 nanoparticles in the diameter range of 5−10 nm were successfully fabricated through a facile surfactant-assisted hydrothermal method. PVP (poly(vinylpyrrolidone)) was applied as surfactant to facilitate the oriented aggregation of small CeO2 nanoparticles into spherical crystallites. The size of as-obtained CeO2 spherical crystallites could be deliberately controlled in the range 100−800 nm by varying synthetic parameters such as the molar ratio of PVP (repeating units) to Ce(NO3)3·6H2O and the concentration of Ce(NO3)3·6H2O solution. The formation mechanism was briefly discussed and the electrochemical properties of as-synthesized CeO2 spherical crystallites were studied by galvanostatic methods. The electrochemical test results show that the as-obtained CeO2 spherical crystallites have promising electrochemical properties that may enable them to be applied as an anode material in lithium ion batteries.

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Large-scale orthorhombic V 2 O 5 single-crystalline nanowires with diameters of 60-80 nm and lengths of up to hundreds of micrometers, which is by far the longest reported one-dimensional nanostructure of vanadium oxide fabricated, were synthesized by a template-free mild and direct hydrothermal reaction between VOSO 4 • xH 2 O and KBrO 3 . The formation mechanism of the as-obtained orthorhombic V 2 O 5 nanowires is briefly discussed. Several parameters, such as pH value in the solution, reaction temperature, and kinds of oxidants, are believed to play an important role in the phase of the final products.

The coprecipitation process, using either mixed nitrate or sulfate solutions, to produce Al-doped Ni 1/3 Mn 1/3 Co 1/3 ͑OH͒ 2 has been studied in detail. Using X-ray diffraction ͑XRD͒ and thermal gravimetric analysis ͑TGA͒, it has been determined that charge-compensating NO 3 − or SO 4 2− ions accompany the incorporated Al 3+ ions into the structure to form layered double hydroxides ͑LDHs͒. The phases formed were determined for 0 Ͻ z Ͻ 1/3 in