CN102795658B

CN102795658B - Method for regulating zinc oxide crystal microstructure by using hydrogen peroxide

Info

Publication number: CN102795658B
Application number: CN201210265989.XA
Authority: CN
Inventors: 张卫华; 夏培康; 张博华
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2012-07-30
Filing date: 2012-07-30
Publication date: 2014-01-08
Anticipated expiration: 2032-07-30
Also published as: CN102795658A

Abstract

The invention discloses a method for regulating zinc oxide crystal microstructure by using hydrogen peroxide, and the method comprises the following steps: step 1, adding zinc oxide powder of micro-nano scale to hydrogen peroxide or the water solution of the hydrogen peroxide at room temperature, with a mol ratio of ZnO:H2H2 =1:(20-200), and stirring uniformly to obtain a mixed solution; step 2, placing the mixed solution in a closed container for reaction at constant temperature, cooling to obtain a precipitate, and after washing the precipitate by water, centrifugal separating and drying the precipitate, obtaining the zinc crystals. The method of the invention is simple in technology, high efficiency, and environment friendly; and the obtained products are a series of zinc oxide crystals with different morphologies and sizes, displaying strong nanometer size effect.

Description

A kind of method that adopts hydrogen peroxide regulation and control zincite crystal microstructure

Technical field

The invention belongs to the inorganic functional material technical field, relate to a kind of method that adopts hydrogen peroxide regulation and control zincite crystal microstructure.

Background technology

At room temperature zinc oxide is hexagonal wurtzite structure, has larger energy gap (3.37eV) and exciton bind energy (60meV), is a kind of semiconductor material of excellence.Nano zine oxide shows the incomparable performance of other traditional material due to nano effects such as having surface effects, dimensional effect, show at aspects such as optics, electricity, magnetics, mechanics the characteristic differed widely with the macro-scale material, it has great using value in fields such as solar cell, photoluminescence, photocatalytic degradation, ultraviolet screener, acoustoelectric device, air-sensitive potteries, becomes the focus of domestic and international research.The performance of zinc oxide is decided by its size, pattern and preparation technology, thereby the research and control of its microstructure is also an important content of nano zine oxide research field.

The preparation method of existing nano zine oxide and equipment, the method adopts chemical vapour deposition technique, first the oxide compound of metallic zinc or zinc is carried out in the melting of metal chamber to induction heating, after the heating object fusing, the burning of introducing combustion flame, obtain nanometer Zinc oxide powder after collection burning gained oxide compound is cooling.The method needs more expensive specific equipment, and the size of zinc oxide and pattern wayward, the product inequality.

The preparation method of existing nano zine oxide, the method adopts hydrothermal synthesis method, first fatty alcohol and zinc acetate are mixed with to mixing solutions, react 2～48h again under 80～300 ℃, obtain nanometer Zinc oxide powder after washing, separation, the method needs the organic additives such as methyl alcohol, ethylene glycol, glycerol, unfavorable to environment, and products therefrom size and pattern inequality.

The preparation method of existing nano zine oxide, the method adds successively sodium lauryl sulphate and zinc chloride in ammonium bicarbonate soln, to after the white depositions washing of gained after reaction, separation, drying, obtain presoma, nano zine oxide is calcined and obtained to the gained presoma in tube furnace, the method need adopt organic additive, can produce obnoxious flavour after calcining, harmful to environment, and products therefrom pattern and size inequality.

The preparation method of existing zinc oxide nanowire, the method first adopts carbonate or supercarbonate to prepare zinc subcarbonate as precipitation agent, again polyoxyethylene glycol is added in the basic carbonate zinc solution and under 180～220 ℃ and reacts 5～24h, washing, separating obtained throw out obtain zinc oxide nanowire, the method products therefrom size inequality, and need to adopt polyoxyethylene glycol to be additive, unfavorable to environmental protection.

In above-described method, the synthetic main one-step method for synthesizing that adopts of clavate zinc oxide, consistence and the homogeneity of its resulting ZnO pattern and size are wayward, and need organic additive or special synthetic method, easily cause reliability of technology to be difficult for the problems such as assurance and environmental pollution, all be not easy to carry out the industrialization technology conversion.

Summary of the invention

The purpose of this invention is to provide a kind of method that adopts hydrogen peroxide regulation and control zincite crystal microstructure, the consistence and the homogeneity that have solved ZnO pattern of the prior art and size are wayward, and need organic additive or special synthetic method, easily cause reliability of technology to be difficult for the problem of assurance and environmental pollution.

The technical solution adopted in the present invention is that a kind of method that adopts hydrogen peroxide regulation and control zincite crystal microstructure, is characterized in that, according to following steps, implements:

Step 1, at room temperature the Zinc oxide powder of micro-nano-scale is joined in the aqueous solution of hydrogen peroxide of 2～16mol/L to mol ratio ZnO:H ₂o ₂=1:(20～200), uniform stirring 30～60min, obtain mixed solution; The diameter of Zinc oxide powder is 150～230nm, and the branch arm lengths is 800～1500nm, and length-to-diameter ratio is 5～7;

Step 2, above-mentioned mixed solution is reacted to 6～24h under 150～200 ℃ of constant temperature in encloses container, cooling rear gained precipitation, through water washing, centrifugation, after 40～100 ℃ of drying 12～24h, obtains zincite crystal.

The invention has the beneficial effects as follows,

1) synthetic route uniqueness, preparation technology is simple and direct, and efficiency is high.

2) without any need for tensio-active agent and modifier, environmentally friendly.

3) zincite crystal that products therefrom is a series of different-shapes and size.Size after regulation and control can vary continuously to nanoscale from micro-meter scale, and excellent footpath variation range is from 10nm～1.5 μ m, and the long variation range of rod is from 40nm～50 μ m, length-to-diameter ratio variation range 3～30.

4) its photocatalytic degradation of dye (methyl orange aqueous solution) performance reduces with the diameter of ZnO nano crystalline substance and sharply increases, in the situation that diameter dimension is less than 200nm, show strong nanometer size effect, its photocatalytic speed constant is 2～6 times left and right of ZnO crystal under the same test condition of micron, submicron-scale, as shown in Figure 1.

5) its photoluminescence performance reduces with the diameter dimension of ZnO nano crystalline substance and sharply increases, and shows obvious nanometer size effect, as shown in Figure 2.

The accompanying drawing explanation

The rate of photocatalytic oxidation that Fig. 1 is products therefrom zinc oxide of the present invention-excellent footpath change curve;

The characteristic emission peak luminous intensity that Fig. 2 is products therefrom zinc oxide of the present invention-excellent footpath change curve;

The excellent footpath that Fig. 3 is products therefrom zinc oxide of the present invention, the mol ratio change curve of excellent personal attendant's zinc oxide/hydrogen peroxide;

Fig. 4 is the scanning electron microscope sem photo of the initial oxidation zinc of each example use;

The scanning electron microscope sem photo that Fig. 5 is the embodiment of the present invention 1 products therefrom zinc oxide;

The scanning electron microscope sem photo that Fig. 6 is the embodiment of the present invention 2 products therefrom zinc oxide;

The photoluminescence 3D spectrum that Fig. 7 is the embodiment of the present invention 2 products therefrom zinc oxide;

The scanning electron microscope sem photo that Fig. 8 is the embodiment of the present invention 3 products therefrom zinc oxide;

The scanning electron microscope sem photo of Fig. 9 embodiment of the present invention 4 products therefrom zinc oxide.

Embodiment

Method of the present invention is to adopt the dissolving-recrystallization principle, regulate and control the zincite crystal microstructure by the ZnO/ hydrogen peroxide ratio in the change system, thereby obtain the new preparation process of controllable from the micron order to the nano level, high-crystallinity, the excellent cluster flower of excellent footpath size shape ZnO crystal.

The method of employing hydrogen peroxide regulation and control zincite crystal microstructure of the present invention comprises the following steps:

Step 1, at room temperature the Zinc oxide powder of micro-nano-scale is joined in the aqueous solution of hydrogen peroxide of 2～16mol/L to mol ratio ZnO:H ₂o ₂=1:(20～200), uniform stirring 30～60min, make and mix fully, obtains mixed solution;

Step 2, above-mentioned mixed solution is reacted to 6～24h under 150～200 ℃ of constant temperature in encloses container, cooling rear gained precipitation, through water washing, centrifugation, after 40～100 ℃ of drying 12～24h, obtains the zincite crystal of a series of different-shapes and size.

The water adopted is deionized water, pure water or distilled water.

The hydrogen peroxide adopted is technical grade, AG or electronic-grade commercialization reagent H ₂o ₂, mass concentration is 27.5%～70%.

The principle of work of the inventive method is: under suitable temperature and pressure condition, dissolving and the recrystallization process of ZnO various degrees under the hydrogen peroxide-water surrounding of different concns, utilize this recrystallization process, controls ZnO/H ₂o ₂mol ratio, just can change the microstructure such as pattern, size of original ZnO crystal, obtains high-crystallinity, the controlled ZnO crystal of microstructure.In the recrystallization range of reaction temperature of 150～200 ℃, the products therefrom pattern is mainly the colored shape of excellent cluster, and its excellent footpath, rod length all reduce and reduce along with the mol ratio of zinc oxide/hydrogen peroxide, as shown in Figure 3.

Embodiment 1

At room temperature Zinc oxide powder (diameter is 150～230nm, and a branch arm lengths is 800～1500nm, and length-to-diameter ratio is 5～7, scanning electron microscope pattern photo as shown in Figure 4) is joined in the hydrogen peroxide solution of 2mol/L, (mol ratio is ZnO:H ₂o ₂=1:20), stir after 30min mixes and react 6h under 200 ℃, through deionized water wash, centrifugation, drying, (control condition is 65 ℃ to the gained precipitation, obtains zincite crystal after 20h).As shown in Figure 5, its single excellent diameter is that 400～1500nm, length are that 30～50 μ m, length-to-diameter ratio are 12～30 to the scanning electron microscope pattern photo of the excellent cluster flower shape ZnO crystal of the high-crystallinity that recrystallization is separated out after the hydrogen peroxide regulation and control.

Embodiment 2

At room temperature Zinc oxide powder (as shown in Figure 4) is joined in the hydrogen peroxide solution of 4mol/L, (mol ratio is ZnO:H ₂o ₂=1:60), stir after 50min mixes and react 24h under 150 ℃, through pure water washing, centrifugation, drying, (control condition is 85 ℃ to the gained precipitation, obtain excellent cluster flower shape zincite crystal 12h), as shown in Figure 6, single excellent diameter is that 180～330nm, length are that 1～2.5 μ m, length-to-diameter ratio are 7～14 to its scanning electron microscope pattern photo; As shown in Figure 7, its excitation wavelength is positioned at 570nm at 300～380nm, emission wavelength at wide emission band, the characteristic peak of 400～700nm to its photoluminescence PL spectrum, has wide uv-absorbing cross section and excellent VISIBLE LIGHT EMISSION characteristic.

Embodiment 3

At room temperature Zinc oxide powder (as shown in Figure 4) is joined in the hydrogen peroxide solution of 8mol/L, (mol ratio is ZnO:H ₂o ₂=1:100), stir after 60min mixes and react 15h under 170 ℃, through deionized water wash, centrifugation, negative pressure drying, (control condition is 40 ℃ to the gained precipitation, obtain flowers shape ZnO Nanocrystal (diameter is that 30～250nm, 600nm～1.5 μ m, length-to-diameter ratio are 10～20) 24h), its SEM scanning electron microscope pattern photo as shown in Figure 8.Also include in addition part ZnO nano whisker (its diameter is 10～20nm, and length is 2～4 μ m).

Embodiment 4

At room temperature Zinc oxide powder (as shown in Figure 4) is joined in the hydrogen peroxide solution of 16mol/L, (mol ratio is ZnO:H ₂o ₂=1:200), stir after 30min mixes and react 10h under 180 ℃, (control condition is 100 ℃, obtains stub shape ZnO Nanocrystal (diameter is that 10～30nm, rod length are that 40～200nm, length-to-diameter ratio are 3～10) after 15h) through distilled water wash, centrifugation, drying for gained precipitation.The SEM scanning electron microscope pattern photo of its excellent cluster flower shape ZnO crystal as shown in Figure 9.

Claims

1. a method that adopts hydrogen peroxide regulation and control zincite crystal microstructure, is characterized in that, according to following steps, implements:

Step 1, at room temperature the Zinc oxide powder of micro-nano-scale is joined in the aqueous solution of hydrogen peroxide of 2～16mol/L to mol ratio ZnO:H ₂o ₂=1:(20～200), uniform stirring 30～60min, obtain mixed solution;

Described hydrogen peroxide is technical grade, AG or electronic-grade commercialization reagent H ₂o ₂, mass concentration is 27.5%～70%;

2. employing hydrogen peroxide according to claim 1 regulates and controls the method for zincite crystal microstructure, and it is characterized in that: described water is deionized water, pure water or distilled water.