Amount Of N2H4 Research Articles

Synthesis of Microstructured ZnO in Hydrazine Hydrate Using a Hydrothermal Method and its Optical Properties

Microstructured ZnO have been synthesized by a simple hydrothermal approach, using ZnCl2as the zinc source and N2H4·H2O as the amine precursor in water-ethylene glycol solution at 120 °C for 8 h. The X-ray diffractrometer pattern indicates the pure phase formation of ZnO. Scanning electron microscope images show that the aspect ratio of the ZnO microrod increases by the amount of N2H4·H2O ranging from 0.5 to 1mL, but continuing to 3ml, the aspect ratio of the ZnO microrods decreases. Moreover, the optical band gaps calculated through UV spectroscopy are found to increase from 2.94 (±0.02) to 3.0 (±0.02) eV for samples synthesized at different amounts of hydrazine hydrate ranging from 0.5 to 1mL, respectively.

Synthesis of octahedral TiO2 single crystals with {101} facets from solid precursor with N2H4 as capping agent

In this work, N2H4 was used as surface-capping agent for the first time to synthesize octahedral anatase TiO2 single crystals with dominant {101} facets from H0.68Ti1.83O4 solid precursor. The resultant particle size of {101} facet enriched TiO2 was around 100 nm. The function of N2H4 in the hydrothermal process is not only to provide a mild basic environment, but also to promote the growth of {101} surface because of its strong reducibility. The amount of N2H4 and precursor added in the solution is also investigated, and the result reveals that nearly 100 % {101} facet can be obtained only if N2H4 were added to a certain amount, while the concentration of precursor has no influence on the final result which means that this reaction can be largely scaled up. In oxygen evolution from photocatalytic water splitting, the {101} facets exhibited different performance using AgNO3 or (NH4)2Ce(NO3)6 as sacrificial agent.

Shape-controlled synthesis of Fe3O4 rhombic dodecahedrons and nanodiscs

Fe3O4 rhombic dodecahedrons with only {110} facets exposed and nanodiscs bounded entirely by {111} facets were fabricated via a one-pot hydrothermal approach. The morphologies, structures and magnetic properties of the rhombic dodecahedrons and nanodiscs were investigated through different analytical tools. Batch experiments indicated that the reaction temperature and amount of N2H4·H2O play important roles in determining the sizes and morphologies of the products. Magnetic analysis revealed that the magnetic properties are closely related to the morphologies of the magnetites. The synthesized Fe3O4 nanocrystals are hoped to have important applications in advanced magnetic materials and catalytic fields.

Synthesis and atmospheric instability of well crystallized rod-shaped V2O4 2H2O powders prepared in an aqueous solution

Synthesis of well crystallized rod-shaped V2O4•2H2O powders of 100 nm in width in an aqueous solution containing NH4VO3 and N2H4•H2O under atmospheric pressure had been investigated. The optimal conditions for atmospherically hot-water treatment at 95°C were found to be as follows: pH 2.5-3.5 and an appropriate amount of N2H4•H2O. How the solution conditions affect the crystal structures and morphologies of the products is discussed. At pH<2.5, no precipitates formed. At pH 4.0-4.5, V10O24•12H2O would generally be obtained if N2H4•H2O was excessive. It was independent of reduction of NH4VO3 solution to tetravalent solids on the dosage of reducing agent N2H4•H2O. The morphologies of the V2O4•2H2O had no obvious relationship with the pH and the dosage of N2H4•H2O. It seems that before treated at 95°C the products were sheet-shaped, and then cleaved along specific crystalline directions after treated, forming rod bunches. The stability of V2O4•2H2O in acid solution and in air was also investigated. The results showed that V2O4•2H2O was unstable in air and could undergo oxidization to be a quasi-amorphous rod-shaped V10O24•12H2O, especially at high pH, with excessive N2H4•H2O, drying at 150°C in flowing air, and/or being exposed to air for several days.

Microwave-assisted synthesis and magnetic property of magnetite and hematite nanoparticles

Nanoparticles of magnetite (Fe3O4) and hematite (α-Fe2O3) have been prepared by a simple microwave heating method using FeCl3, polyethylene glycol and N2H4·H2O. The amount of N2H4·H2O has an effect on the final phase of Fe3O4. The morphology of α-Fe2O3 was affected by the heating method. Crystalline α-Fe2O3 agglomerates were formed immediately at room temperature and most of these nanoparticles within agglomerates show the same orientation along [110] direction. After microwave heating, ellipsoidal α-Fe2O3 nanoparticles were formed following an oriented attachment mechanism. Both Fe3O4 and α-Fe2O3 nanoparticles exhibit a small hysteresis loop at room temperature.