Method for preparing multilayer alpha-Ni(OH)2 or NiO nanocrystal by microwave solvothermal method

Abstract

The invention relates to a method for preparing multilayer alpha-Ni(OH)2 or NiO nanocrystal by a microwave solvothermal method, which is characterized by adopting any nickel salt (such as Ni(NO3)2.6H2O, Ni(Ac).4H2O, NiCl2.6H2O and the like) as a single raw material and adopting a saturated monobasic alcohol in a liquid state at room temperature as a single solvent (such as ethanol, isopropanol, normal propyl alcohol and the like), and comprising the following steps: under the conditions that the reaction temperature is 150 DEG C and the reaction time is 15min, carrying out solvothermal reaction to obtain an alpha-Ni(OH)2 multilayer nano structure with uniform size; and obtaining the porous NiO multilayer nanocrystal by a calcining process. The invention is also applicable to preparation of multilayer nanocrystals of other transition metal hydroxides and oxides. In the invention, the defect that extra soft and hard templates or an auxiliary precipitation control agent is often needed in the prior methods for preparing the multilayer NiO nanocrystal is overcome.

Description

technical field [0001] The invention relates to a microwave solvothermal method for preparing multilayer α-Ni(OH) 2 Or the method of NiO nanocrystals, more precisely, it provides a microwave solvothermal method for preparing α-Ni(OH) without any templating agent and precipitating agent 2 And the method of NiO flower-like nanocrystal can be used for energy storage, photocatalysis, environmental protection, magnetic semiconductor, etc., and belongs to the field of nanomaterials. Background technique [0002] In recent years, controlled synthesis of hierarchical nanomaterials has been one of the hotspots in material science research. Because of its special physical and chemical properties, such as large specific surface area, functionalized surface, etc., it is not only helpful to understand the technology of controlling the synthesis of nanomaterials with various structures, but also will be used in electromagnetism, electronics, etc. It has great application prospects in ch...

AI Technical Summary

Problems solved by technology

It is because of its unique layered structure that α-Ni(OH) 2 and β-Ni(OH) 2 Compared with it, it has better electrochemical performance, but because it is easy to undergo phase transformation into β phase, α-Ni(OH) 2 It is more difficult to synthesize, and due to the special ion intercalation structure of the α phase, the lattice spacing in the C-axis direction is much larger than that of the β phase, so it is difficult to control the three-dimensional ordered multi-level nanostructure

[0004] At present, the successful synthesis of three-dimensional ordered α-Ni(OH) 2 According to reports on multi-level nanostructures, Jeevanandam used urea as a precipitant and heated it ultrasonically to synthesize cotton-like α-Ni(OH) 2 , but the product has serious agglomeration and poor size dispersion (1-5 μm) (Jeevanandam, P. et al, Nano Letters, 2001, 1, 263)

Liu used hexamethylenetetramine (HMT) as a stabilizer and precipitation control agent to obtain flower-like α-Ni(OH) by hydrothermal reaction. 2 , but the product size is large (5-10μm), and the study did not give specific surface area data ((Liu, H.J.et al, Mater.Chem.Phys., 2004, 87, 81.); Xu in the mixed solvent of ethanol and water α-Ni(OH) with relatively uniform size was prepared in 2 flower-like nanostructure, but must rely on the precipitation control agent urea to control the morphology of the product (Xu, L.P. et al, Chemistry of Materials, 2008, 20, 308); Liu, B.H. et al, J.Phys.Chem.B, 2006, 110, 4039.)

Therefore, there is still no preparation of three-dimensional ordered multi-level α-Ni(OH) without any soft and hard templates or precipitation control agents. 2 and reports on NiO nanocrystals

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