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The shape-controlled synthesis of NiCo2 O4 microstructures through a facile hydrothermal method and subsequent calcinations was explored. By employing CoSO4 , NiSO4 , and urea as the starting reactants, flower-like NiCo2 O4 microstructures were obtained at 100 °C after 5 h without the assistance of any additive and subsequent calcination at 300 °C for 2 h; dumbbell-like NiCo2 O4 microstructures were prepared at 150 °C after 5 h in the presence of trisodium citrate and subsequent calcination at 300 °C for 2 h. The as-prepared NiCo2 O4 microstructures were characterized by X-ray powder diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and (high-resolution) transmission electron microscopy. Both the flower-like and dumbbell-like NiCo2 O4 microstructures could be used as electrode materials for supercapacitors, and they exhibited excellent electrochemical performance, including high specific capacitance, good rate capability, and excellent long-term cycle stability. Simultaneously, the shape-dependent electrochemical properties of the product were investigated.

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A facile and environment-friendly approach for synthesis of flowerlike copper-based coordination polymer particles (CPPs) was reported. Copper acetate (CuAc 2 ) and sodium pyridine-2,3-dicarboxylate (2,3-Na 2 PDC) were used as the initial reactants. The flowerlike Cu-PDC microstructures were obtained based on a simple direct precipitation between CuAc 2 and 2,3-Na 2 PDC in a mixed solution of water and methanol with the volume ratio of 20:10 at room temperature. The asobtained products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and elemental analysis. Some factors to affect the morphology and size of the Cu-PDC microstructures were systematically investigated such as the molar ratio of reactants, the volume ratio of water/methanol, acetic groups, and the reaction time. It was found that flowerlike Cu-PDC microstructures could be transformed into flowerlike CuO microstructures by heat-treating in air at 350 °C for 30 min. Experiments showed that the asobtained flowerlike CuO microstructure exhibited a high catalytic activity for the reduction of 4-nitrophenol in excess NaBH 4 solution.

Coral-like BaTiO 3 nanostructures have been successfully synthesized via a simple hydrothermal route at 150 °C for 15 h, employing BaCl 2 , tetrabutyltitanate [(C 4 H 9 O) 4 Ti] and NaOH as original reactants without the assistance of any surfactant or template. The phase of the as-obtained BaTiO 3 was characterized by X-ray powder diffraction (XRD). Energy dispersive spectrometry (EDS), scanning 10 electron microscopy (SEM) and (high-resolution) transmission electron microscopy (TEM/HRTEM) were employed for the composition and morphology analyses of the final product. Some factors influencing the formation of coral-like BaTiO 3 nanostructures were investigated, including the amount of original NaOH, the barium ion source, and the reaction temperature and time. Experiments showed that the as-prepared coral-like BaTiO 3 nanostructures presented good photocatalytic activity for the 15 degradation of methyl orange (MO) dye under the irradiation of the mimic sunlight. It was found that the photocatalytic activity of coral-like BaTiO 3 nanostructures could be affected by the pH value of the system.