CN101823703B - Controllable preparation method for petaliform tin oxide nano powder - Google Patents

Abstract

The invention discloses a controllable preparation method for petaliform tin oxide nano powder, which is mainly characterized in that SnCl2 and NaOH serve as raw materials. The method comprises the following detailed steps: dissolving the SnCl2 and NaOH in deionized water respectively to prepare a tin salt suspension of which the concentration is 0.2 to 0.4mol/L and NaOH solution of which the concentration is 0.3 to 1mol/L; under magnetic stirring, uniformly dripping the NaOH solution into the tin salt solution until the pH value is between 11 and 13, and stirring the solution for 2 to 3 hours to obtain SnO2 precursor; pouring the precursor into a water heating reaction kettle for water heating treatment for 12 to 24 hours at the temperature of 160 to 200 DEG C; and washing and drying the obtained product, and obtaining the petaliform SnO2 powder consisting of single crystal nano sheets of which the thickness is about 3 to 10nm. No any surfactant is added. The method has the characteristics of high quality and yield of the product, low cost, massive production and the like, and is an environment-friendly synthetic method.

Description

A kind of controllable method for preparing of spending the sheet tin oxide nano-powder

Technical field

The present invention relates to a kind of colored sheet SnO ₂The preparation method of nano-powder, this powder can be applicable to fields such as gas sensor material and photocatalyst material.

Background technology

SnO ₂Have fabulous photoelectric characteristic and to the sensitive property of reducing gas, be widely used in gas sensor material and and field such as photocatalyst material at present.Work as SnO ₂After the crystal particle scale of material got into nano level, owing to the exclusive dimensional effect of nano material, quantum size effect and surface effects etc. show many special physicochemical character, its gas-sensitive property and catalysis characteristics all had significantly lifting.Therefore, to SnO ₂The controlled preparation of the microscopic appearance of nano material, particle diameter and crystalline structure is most important to improving its gas-sensitive property and catalysis characteristics.

In recent years, researcher has been prepared the SnO of multiple patterns such as particulate state, nano wire/nanometer rod/nanoneedle, hollow ball, nanometer plate ₂Nano material.Related preparation method has the physics method that comprises magnetron sputtering, atomic ray deposition, electron beam deposition and high-temp combustion synthesis method etc.; And comprise chemical gas phase oxidation, direct chemical method such as synthetic, collosol and gel of deposition, hydro-thermal and template, the synthetic SnO of institute ₂The shape major part of nano material is particulate state, one dimension wire and hollow ball structure, and only a few presents sheet or flower-shaped.For example, Journa of AmericanChemical Society, 2002,124, " Growth and Structure Evolution of Novel TinOxide Diskettes " reported with the vapor coating legal system and has been equipped with SnO among the 8673-8680 ₂The technology of nanometer monocrystalline dish, the investigator is that the mode that starting material pass through high temperature oxidation forms monocrystalline SnO with the SnO powder ₂Nanometer plate.Sensors andActuators B in 2006,2006,113, " High ethanol sensitive SnO2 microspheres " reported a kind of with SnCl among the 937-943 ₂With the sulphur powder be that raw material at high temperature is oxidized to flower-shaped SnO with SnS with chemical Vapor deposition process ₂The method of microballoon.Compare prepared by physical method SnO ₂Higher to equipment requirements, be used for film preparation more; And the cost of chemical method is relatively low, and is easy to operate, is suitable for industrial production in enormous quantities.Yet though the above-mentioned chemical Vapor deposition process easily-controlled reaction conditions of using, Technology is complicated, cost is high, one-time investment is big.

Compare with general wet-chemical reaction method, hydrothermal method can directly generate crystal, and prepared powder granule is even, and percent crystallinity is high, and crystalline state is complete, thereby makes one of its important technology that becomes multiple nano oxide powder preparation.Journalof Nanoparticle Research; 2006; 8, " Facile synthesis and optical property ofSnO2 flower-like architectures " reported with KBrO3, NaOH and tinfoil paper to be that raw material has synthesized a type flower-shaped SnO with hydrothermal method among the 1065-1069 ₂Method.In addition, Journal of Crystal Growth, 2006,291, " Hydrothermalsynthesis and characterization of novel flower-like zinc-doped SnO2 nano-crystals " reported with SnCl among the 258-261 ₄With NaOH be that raw material passes through ZnCl ₂Doping the has utilized Hydrothermal Preparation flower-shaped SnO that forms by nanoneedle ₂According to Materials Letter; 2007; 61, " Synthesis of novel hexagon SnO2 nanosheetsin ethanol/water soltion by hydrothermal process " report of 3705-3707 is through regulating and control water and alcoholic acid volume ratio with SnCl ₄, NaOH and template CTAB be that raw material has been realized SnO ₂The controlled preparation of nanometer sheet shape and size.With reported method is different before, the present invention is mainly directly with SnCl ₂With NaOH be that raw material adopts the non-template hydrothermal method to realize the colored sheet SnO that is self-assembled into by single crystal nanoplate ₂The controlled preparation of nano-powder can be controlled SnO through regulation and control water and alcoholic acid volume ratio ₂The thickness of nanometer sheet and the yardstick on the two-dimensional direction.Present method is not added any tensio-active agent, have that product quality height, productive rate are high, cost is low and can scale prodn etc. characteristics, be a kind of environmentally friendly compound method.The colored sheet SnO that obtains ₂Be rutile phase structure and monolithic SnO ₂Be monocrystalline.Through sign, find that this powder has special photoabsorption peak position, might improve SnO greatly to the ultraviolet-visible optical absorption characteristics of powder ₂Photoelectric characteristic.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of directly with SnCl to the above-mentioned state of the art ₂With NaOH be that raw material adopts the non-template hydrothermal method to realize the colored sheet SnO that is self-assembled into by single crystal nanoplate ₂The controllable method for preparing of nano-powder, it can control SnO through regulation and control water and alcoholic acid volume ratio ₂The thickness of nanometer sheet and the yardstick on the two-dimensional direction, and do not add any tensio-active agent, have the product quality height, productive rate is high, cost is low and can scale prodn etc. characteristics, be a kind of environmentally friendly compound method.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of controllable method for preparing of spending the sheet tin oxide nano-powder is characterized in that steps in sequence is:

A. with SnCl ₂Be dissolved into ethanol and water volume ratio and be in 0～1 the alcohol-water mixture or the aqueous solution, be stirred to the white suspension liquid that forms 0.2～0.4mol/L then; With NaOH be dissolved in the water as a certain amount of deionized water in, stir then until the NaOH solution that forms 0.4～1mol/L;

B. under strong mixing, NaOH solution is dropped in the above-mentioned white suspension liquid uniformly, between 11～13, and then stir 2～3h, form presoma suspension liquid with black precipitate until the pH value;

C. above-mentioned presoma suspension liquid is transferred in the hydrothermal reaction kettle,, naturally cooled to room temperature then at 160～200 ℃ of following hydrothermal treatment consists 12～24h;

D. successively with the hydrothermal product washing for several times, until with Cl with deionized water and ethanol ^-Remove fully, 70～90 ℃ of oven dry 1～2h obtain khaki SnO under the condition of vacuumizing ₂Nano-powder.

Described washing is with deionized water and ethanol hydrothermal product to be washed respectively for several times successively, generally uses deionized water wash 4 times, with washing with alcohol 2 times, until with Cl ^-Remove fully.

Concrete washing methods is:

A. product is moved into respectively in the centrifuge tube equably, then, in centrifuge tube, inject the deionized water of suitable volumes;

B., the symmetric supercentrifuge of putting into of centrifuge tube of product and deionized water will be housed, set rotating speed (being generally 6000～8000 rev/mins) and time (general 10～15 minutes/inferior), and start whizzer and accomplish once washing;

C. next according to identical operations, use deionized water and washing with alcohol for several times successively, until with Cl ^-Remove fully.

Compared with prior art, the invention has the advantages that:

A. the colored sheet SnO that obtains ₂Nano-powder has single tetragonal system rutile-type structure, is assembled into flower-shapedly by single crystal nanoplate, and the thickness of sheet is in 3～10nm scope, and is and controlled;

B.SnO ₂Nano-powder has higher specific surface area and unique optical absorption characteristics, and specific surface area is at 42.6～93.2m ²Between/the g, the optical absorption peak corresponding wavelength is 331nm, sees accompanying drawing 4;

C. raw material is simple and easy to, and cost is low, and technology is simply pollution-free, suitability for industrialized production.

Description of drawings

Fig. 1. be flower sheet SnO ₂The X-ray diffractogram of nano-powder can find out that sample purity is high, good crystallinity, and with JCPDS card 41-1445 (space group:P42/mnm, a _o=4.74 , c _o=3.19

) each peak corresponding (be rutile-type structure, the genus tetragonal system).

Fig. 2 a and 2b. are flower sheet SnO ₂The field emission scanning electron microscope figure of nano-powder can find out the SnO of monolithic ₂The thickness of nanometer sheet is between 3～5nm, SnO ₂Nanometer sheet and be self-assembled into micron-sized floriform appearance.

Fig. 3. be flower sheet SnO ₂The transmission electron microscope picture of nano-powder can be found out monolithic SnO ₂On two-dimensional directional, being about is 1 μ m, the wide 500nm that is about.Corresponding (110) crystal face of upper left high resolution TEM, corresponding [001] crystal orientation of bottom-right SAED.

Fig. 4. be flower sheet SnO ₂The optical absorption characteristics that nano-powder is corresponding can be found out the absorption peak that the last one arranged at the 331nm place, usually SnO ₂Absorption peak be 306nm, can find out that its absorption peak generation red shift promptly moves to high wavelength significantly.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

Practical implementation instance 1:

A. the anhydrous SnCl of weighing 1.3539g ₂Be dissolved in the 20ml water, then 10 minutes white suspension liquids of magnetic agitation until formation 0.3mol/L.The NaOH of weighing 0.8g is dissolved in the 20ml deionized water, and magnetic agitation is to the transparent NaOH solution that forms 1.0mol/L then.

B. under strong magnetic agitation, transparent NaOH solution being dropped in the above-mentioned white suspension liquid uniformly, is 11 until the pH value, and then magnetic agitation 3h, forms the presoma suspension liquid with black precipitate.

C. above-mentioned presoma suspension liquid is transferred to in the 100ml reaction kettle,, naturally cooled to room temperature then at 200 ℃ of following hydrothermal treatment consists 24h.

D. successively with the hydrothermal product washing for several times, until with Cl with deionized water and ethanol ^-Remove fully, 70 ℃ of oven dry 1h obtain khaki SnO under the condition of vacuumizing ₂Nano-powder, its specific surface area are 51.6m ²/ g.SnO ₂The thickness of nanometer sheet is about 3～5nm, the wide 500nm that is about, and being about is 1 μ m.

Practical implementation instance 2:

A. the anhydrous SnCl of weighing 1.3539g ₂Separate in the mixed solution of 5ml ethanol and 15ml water (volume ratio is 1: 3), then 10 minutes white suspension liquids of magnetic agitation until formation 0.3mol/L.Weighing 0.8g NaOH is dissolved in the 50ml deionized water, and magnetic agitation forms the transparent NaOH solution of 0.4mol/L then.

B. under strong magnetic agitation, transparent NaOH solution being dropped in the above-mentioned white suspension liquid uniformly, is 13 until the pH value, and then magnetic agitation 2h, forms the presoma suspension liquid with black precipitate.

C. above-mentioned presoma suspension liquid is transferred to in the 100ml reaction kettle,, naturally cooled to room temperature then at 180 ℃ of following hydrothermal treatment consists 12h.

D. successively with the hydrothermal product washing for several times, until with Cl with deionized water and ethanol ^-Remove fully, 70 ℃ of oven dry 1h obtain khaki SnO under the condition of vacuumizing ₂Nano-powder, its specific surface area are 93.2m ²/ g.SnO ₂The thickness of nanometer sheet is about 5～10nm, and the wide 200nm that is about is about and is 500nm.

The strong mixing that relates in the building-up process does not have specific requirement, and generally speaking, the stirring intensity when dripping NaOH solution is bigger than other processes.

The sign of powder: Fig. 1-3 is respectively a typical production and obtains flower sheet SnO ₂The X-ray diffractogram of nano-powder (XRD), field emission scanning electron microscope figure (FESEM), transmission electron microscope picture (TEM).

Claims (2)

1. controllable method for preparing of spending the sheet tin oxide nano-powder is characterized in that steps in sequence is:

A. with SnCl ₂Be dissolved into ethanol and water volume ratio and be in 0～1: 1 the alcohol-water mixture, stir then until the white suspension liquid that forms 0.2～0.4mol/L; NaOH is dissolved in the water, stirs then until the NaOH solution that forms 0.4～1mol/L;

B. under strong mixing, NaOH solution is dropped in the above-mentioned white suspension liquid uniformly, between 11～13, and then stir 2～3h, form presoma suspension liquid with black precipitate until the pH value;

C. above-mentioned presoma suspension liquid is transferred in the hydrothermal reaction kettle,, naturally cooled to room temperature then at 160～200 ℃ of following hydrothermal treatment consists 12～24h;

D. successively with the hydrothermal product washing for several times, until with Cl with deionized water and ethanol ^-Remove fully, 70～90 ℃ of oven dry 1～2h obtain khaki SnO under the condition of vacuumizing ₂Nano-powder.

2. controllable method for preparing according to claim 1 is characterized in that washing is with deionized water and ethanol hydrothermal product to be washed several respectively successively, until with Cl ^-Remove fully.

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