Rose-like Morphology Research Articles

Preparation of 3D rose-like NiO complex structure and its electrochemical property

The reaction of nickel chloride and sodium acetate under solvothermal conditions produced Ni(OH) 2 nanoplatelets, which are self-assembled to form a 3D rose-like morphology. After calcination, NiO nanoplatelets were obtained and inherited the rose-like morphology of Ni(OH) 2 precursor. The influences of PEG and reaction temperature on the size and morphology of NiO were investigated. The functions of PEG on the formation of the NiO nanoplatelets and the self-assembly process were discussed. Moreover, the possible mechanism for the formation of rose-like morphology was proposed. The cyclic voltammetry (CV) measurement showed that as-prepared NiO with a rose-like morphology exhibited a good pseudo-capacitance behavior.

Surface fabrication of oxides via solution chemistry

A template- and catalyst-free strategy has been successfully designed to prepare MgO and hydrated magnesium carbonate hydroxide (Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O) nanosheets with different patterns (such as chrysalides- and rose-like morphology) on the substrate surface. Experimental results reveal that the temperature and substrate allow us to tune the morphology of patterns. Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O thermodynamically prefers to grow into the sheet-like crystal at the current solution growth environment, which has been successfully explained by using the chemical bonding theory. The predicted morphology can accord well with the current experimental results. The obtained MgO and its precursor Mg 5 (CO 3 ) 4 (OH) 2 ·4H 2 O with novel patterns might find enhanced applications in catalysis, refractory materials, plastics, fire retardants, and functional nanodevices.

Synthesis, structure and photoelectrochemical performance of micro/nano-textured ZnO/eosin Y electrodes

Micro/nano-textured ZnO thick films were synthesized through deposition and pyrolysis of layered hydroxide zinc acetate (LHZA), Zn 5(OH) 8(CH 3COO) 2·2H 2O. LHZA films having a unique, rose-like morphology were initially deposited on conducting glass sheets in a chemical bath composed of methanol and zinc acetate dihydrate at 60 °C under neutral conditions. Pyrolysis of the LHZA films resulted in formation of ZnO without destroying the original morphology. Pyrolysis temperatures were found to greatly influence grain sizes and specific surface areas of the ZnO films. Photoelectrochemical performance of the films as ZnO/eosin Y electrodes was investigated in dye-sensitized solar cells using an I −/I 3 − redox electrolyte solution. The cell using the ZnO film pyrolyzed at 150 °C exhibited overall light to electricity conversion efficiencies of 2.0 and 3.3% under an AM-1.5 illumination at 100 and 10 mW cm −2, respectively. While microscale pores in the electrodes facilitated mass transfer of fluid electrolytes in the depth direction, nanoscale pores contributed to an increase in the amount of adsorbed dye. The maximum incident photon-to-current conversion efficiency (IPCE) of the electrode reached 84.9% at a wavelength of 530 nm.

TEM STUDY OF CRYSTALLIZATION BEHAVIOUR OF Ni51Zr49 AMORPHOUS ALLOY

The crystallization behaviour of Ni51Zr49 amorphous alloy has been studied by the transmission electron microscopy (TEM). It has been found that a metastable phase, NiZr, in rose-like morphology with C-centered monoclinic lattice, a = 0.3268, b = 0.4101, c = 0.5224nm and β= 71.8° in amorphous matrix in the earlier stage of the crystallization, The following orientation relationships between the metastable phase and the stable phase, NiZr, exist: [100]NiZr＇//[100]NiZr [001]NiZr＇//[ll0]NiZr. NiZr＇ phase is regarded as a metastable state of NiZr phase and transforms to NiZr phase gradually with an increase in temperature. A small quantity of Ni10Zr7 phase formed in the final stage of the crystallization. Both NiZr and NiZr＇ have complex twins with two principle typies, one of which is 180°twins with the [02l] direction of NiZr or NiZr＇ as axis and another 36°rotation twins with [001] of NiZr or [010] of NiZr＇ as axis. The total amount of twins decrease gradually with the increase in temperature.