CN104528814A

CN104528814A - Preparation method and product of CaTi2O4(OH)4 diamond nanosheet with lamellar structure

Info

Publication number: CN104528814A
Application number: CN201410795349.9A
Authority: CN
Inventors: 徐刚; 杨永荣; 白惠文; 邓世琪; 沈鸽; 韩高荣
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2014-12-19
Filing date: 2014-12-19
Publication date: 2015-04-22
Anticipated expiration: 2034-12-19
Also published as: CN104528814B

Abstract

The invention discloses a preparation method of a CaTi2O4(OH)4 diamond nanosheet with a lamellar structure. The method comprises the following steps: mixing tetrabutyl titanate with ethylene glycol monomethyl ether or ethyl alcohol, so as to obtain a 0.2-0.5M tetrabutyl titanate solution; adding an ammonia-water solution to adjust the pH value to 10-11, standing to obtain titanium oxyhydroxide sediments; mixing the titanium oxyhydroxide sediments, calcium nitrate and tetramethylammonium hydroxide with water, and stirring evenly, so as to obtain precursor slurry; and carrying out hydrothermal reaction, and then processing, so as to obtain the CaTi2O4(OH)4 diamond nanosheet with the lamellar structure, wherein the concentration of tetramethylammonium hydroxide in the precursor slurry is 0.05-0.1M; and the concentration of calcium nitrate is 0.1-0.2M. Through accurate regulation and control on the reaction condition, the Ti2O4(OH)4 diamond nanosheet with the lamellar structure is obtained by one-step hydrothermal reaction; and the preparation process is simple and easy to control.

Description

A kind of laminate structure CaTi 2o 4(OH) 4the preparation method of rhombus nanometer sheet and product

Technical field

The present invention relates to the preparation field of ceramic, particularly relate to a kind of laminate structure CaTi ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet and product.

Background technology

The extended familys of huge number, abundant species during titanium calcium oxide, thus, calcium titanium oxide also presents the character of many novelties, CaTi ₂o ₄(OH) ₄a kind of special calcium titanium oxide be made up of calcium, titanium, oxygen element, it is as far back as being just found decades ago, but because its crystalline structure is still in unknown state, it is called as Kassite structure, being similar to hydrotalcite structure, is by the main body laminate of calcium oxygen octahedra and titanyl octahedral body and interlayer OH ^-by the compound that the interaction of non covalent bond is assembled.

At present, CaTi ₂o ₄(OH) ₄preparation mainly contain conventional solid reaction method, wet chemistry method, template, vapor phase process and molten-salt growth method etc., conventional solid reaction method is the means of industrial extensive employing, recent years vapor phase process and molten-salt growth method just grow up, but there is dephasign to exist in the product prepared by these methods, easily be easily polluted by the external foreign matters, the uneven first-class shortcoming of high thermal treatment temp, longer treatment time and particle size distribution.For overcoming these problems, wet chemistry method preparation seems more effective, as sol-gel method, inorganic salt sol-gel, metal alkoxide hydrolysis, co-precipitation, polymeric precursor, hydrothermal method and hydro-thermal-electrochemical process, these methods can improve calcium titanium oxide structure and the relation between pattern and performance.Wherein, hydrothermal method can by adjusting process parameter or interpolation tensio-active agent control crystal growth, the pattern of acquisition anticipation simply.

CaTi is prepared as the publication number Chinese patent literature that is CN102583520A discloses one ₂o ₄(OH) ₄the method of nanometer layer, is first dissolved in alcohol solvent by titanyl compound, obtains A liquid; Again Calcium dichloride dihydrate, distilled water and alcohol solvent are mixed, obtain B liquid; A liquid is dropwise instilled in B liquid slowly, adjust ph to 8 ~ 12, after being uniformly mixed, at 180-260 DEG C, being incubated 1 ~ 36h, obtaining CaTi ₂o ₄(OH) ₄nanometer layer.The poor controllability of this preparation method, the CaTi prepared ₂o ₄(OH) ₄the pattern of nanometer layer and size very irregularity, is unfavorable for that it is applied further.

CaTi ₂o ₄(OH) ₄nanometer layer has great specific surface area, and the lamellar structure compound functional materials that to be a class novel, its distinctive laminate structure and interlayer chemical reactivity and good ion-exchange and characterization of adsorption make it have broad application prospects at numerous areas such as luminescence, ion-exchange, absorption, conduction and photochemical catalysis.And the CaTi of the more different-shapes of exploitation ₂o ₄(OH) ₄nanometer layer will be conducive to it and apply further.

Summary of the invention

The present invention is with the oxyhydroxide precipitation agent of titanium, nitrocalcite for reaction mass, and the Tetramethylammonium hydroxide of lower concentration is mineralizer, by the accuracy controlling to reaction conditions, obtains the CaTi with laminate structure through a step hydro-thermal reaction ₂o ₄(OH) ₄rhombus nanometer sheet, preparation technology is simple, is easy to control.

A kind of laminate structure CaTi ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, step is as follows:

1) tetrabutyl titanate is mixed with ethylene glycol monomethyl ether or ethanol, obtain tetrabutyl titanate/ethylene glycol monomethyl ether solution that tetrabutyl titanate concentration is 0.2 ~ 0.5mol/L or tetrabutyl titanate/ethanolic soln, add ammonia soln again, adjust ph to 10 ~ 11, leave standstill, obtain the oxyhydroxide precipitation of titanium through aftertreatment;

2) by step 1) the oxyhydroxide precipitation of the titanium that obtains, nitrocalcite, Tetramethylammonium hydroxide mix with water, stir and obtain precursor pulp, at 200 ~ 240 DEG C after hydro-thermal reaction 12 ~ 24h, then obtain laminate structure CaTi through aftertreatment ₂o ₄(OH) ₄rhombus nanometer sheet;

In described precursor pulp, the concentration of Tetramethylammonium hydroxide is 0.05 ~ 0.1mol/L, and the concentration of nitrocalcite is 0.1 ~ 0.2mol/L.

As preferably, step 1) in, the concentration of described ammonia soln is 30%, and under this concentration, tetrabutyl titanate can be converted into the oxyhydroxide of titanium within a short period of time completely.

Further preferably, step 1) in, gently stir 2 ~ 3 times before leaving standstill, ammoniacal liquor is evenly spread, keep the stable of solution PH, the described standing time is 2 ~ 5min, makes tetrabutyl titanate be converted into oxyhydroxide precipitation completely.

Preferred again, step 2) in, in described precursor pulp, the concentration of nitrocalcite is 0.11 ~ 0.165mol/L, and calcium titanium is than being 1.1:1.

By the accurate control to above-mentioned condition, what ability was controlled obtains laminate structure CaTi ₂o ₄(OH) ₄rhombus nanometer sheet.

Hydro-thermal reaction in the present invention, with polytetrafluoroethylliner liner, is carried out in the reactor that stainless steel external member is airtight, and as preferably, in reactor, compactedness is 30 ~ 80%.

Step 2) in, described last handling process is specially:

Reactor is cooled to room temperature, takes out reaction product, after filtering, use deionized water, ethanol purge successively, then dry at 60 ~ 80 DEG C.

The laminate structure CaTi that preparation method described in a kind of basis obtains ₂o ₄(OH) ₄rhombus nanometer sheet, nanometer sheet long-diagonal is 400 ~ 1200nm, and short diagonal is 300 ~ 500nm, and thickness is 5 ~ 12nm.Laminate structure CaTi prepared by the present invention ₂o ₄(OH) ₄rhombus nanometer sheet has great specific surface area, and the lamellar structure compound functional materials that to be a class novel, its distinctive laminate structure and interlayer chemical reactivity and good ion-exchange and characterization of adsorption make it have broad application prospects at numerous areas such as luminescence, ion-exchange, absorption, conduction and photochemical catalysis.And the CaTi of the more different-shapes of exploitation ₂o ₄(OH) ₄nanometer sheet will be conducive to it and apply further.

Compared with prior art, tool of the present invention has the following advantages:

The present invention introduces the Tetramethylammonium hydroxide of lower concentration as mineralizer in hydrothermal system, and not only direct ionization goes out OH ^-ion, and the organic cation discharged is easy to be adsorbed on plane of crystal, changes product formation mechenism, product pattern is changed, is changed by irregular laminated structure nano layer to rhombus nanometer sheet; Also adopt nitrocalcite to replace Calcium dichloride dihydrate as calcium source, avoid because the CO in absorbed air ₂gas and introduce impurity.

The present invention utilizes a simple step hydro-thermal reaction method to prepare laminate structure CaTi ₂o ₄(OH) ₄rhombus nanometer sheet, technological process is simple, is easy to control, and pollution-free, cost is low, is convenient to amplify produce.

The laminate structure CaTi that the present invention prepares ₂o ₄(OH) ₄the purity of nanometer sheet is good, and degree of crystallinity is high, size uniform and morphology controllable.

Accompanying drawing explanation

Fig. 1 is laminate structure CaTi prepared by embodiment 1 ₂o ₄(OH) ₄the XRD figure spectrum of the preparation method of rhombus nanometer sheet;

Fig. 2 is laminate structure CaTi prepared by embodiment 1 ₂o ₄(OH) ₄the stereoscan photograph of the preparation method of rhombus nanometer sheet.

Embodiment

The present invention is further illustrated below in conjunction with embodiment.

Embodiment 1

1) 4mmol tetrabutyl titanate is dissolved in 20ml ethylene glycol monomethyl ether, obtains the ethylene glycol monomethyl ether solution that tetrabutyl titanate concentration is 0.2mol/L;

2) to 1) add the ammonia soln that 2.5ml mass concentration is 30% in obtained tetrabutyl titanate ethylene glycol monomethyl ether solution, glass stick gently stirs 2 times, leaves standstill 2min precipitation, filters, and by washed with de-ionized water 3 times, obtains the oxyhydroxide precipitation of titanium;

3) by step 2) oxyhydroxide of gained titanium precipitation, nitrocalcite crystal and Tetramethylammonium hydroxide crystal join in reactor inner bag successively, and be 4/5 of reactor with deionized water instrumentality material volume, stir 1 hour, calcium titanium is than being 1.1:1, the volumetric molar concentration of Tetramethylammonium hydroxide is 0.05mol/L, and the volumetric molar concentration of nitrocalcite is 0.11mol/L, and the volume radix of the volumetric molar concentration in this step is the cumulative volume of precursor pulp in reactor inner bag;

4) the reactor inner bag of precursor pulp will be housed as in reactor, sealing, at 200 DEG C, insulation carries out hydrothermal treatment consists in 3 hours, then allow reactor naturally cool to room temperature, take out reactant, filter, use deionized water, ethanol purge successively, dry at 80 DEG C, obtain laminate structure CaTi ₂o ₄(OH) ₄rhombus nanometer sheet material.

The XRD figure of the present embodiment preparing product as shown in Figure 1, its diffraction peak and CaTi ₂o ₄(OH) ₄the standard diagram of phase is consistent.The electromicroscopic photograph of the present embodiment preparing product as shown in Figure 2.Can find out that from electromicroscopic photograph products therefrom is laminated structure nano sheet, nanometer sheet long-diagonal is 400 ~ 1200nm, and short diagonal is 300 ~ 500nm, and thickness is 5 ~ 12nm.

Embodiment 2

1) 6mmoL tetrabutyl titanate is dissolved in 12ml ethylene glycol monomethyl ether, obtains the ethylene glycol monomethyl ether solution that tetrabutyl titanate concentration is 0.5mol/L;

2) to 1) add the ammonia soln that 3ml mass concentration is 30% in obtained tetrabutyl titanate ethylene glycol monomethyl ether solution, glass stick gently stirs 2 times, leaves standstill 2min precipitation, filters, and by washed with de-ionized water 4 times, obtains the oxyhydroxide precipitation of titanium;

3) by step 2) the oxyhydroxide precipitation of the titanium of gained, nitrocalcite crystal and Tetramethylammonium hydroxide crystal join in reactor inner bag successively, and be 2/3 of reactor with deionized water instrumentality material volume, stir 3 hours, calcium titanium is than being 1.1:1, the volumetric molar concentration of Tetramethylammonium hydroxide is 0.1mol/L, and the volumetric molar concentration of nitrocalcite is 0.165mol/L, and the volume radix of the volumetric molar concentration in this step is the cumulative volume of precursor pulp in reactor inner bag;

4) the reactor inner bag of precursor pulp will be housed as in reactor, sealing, at 200 DEG C, insulation carries out hydrothermal treatment consists in 24 hours, then allow reactor naturally cool to room temperature, take out reactant, filter, use deionized water, ethanol purge successively, dry at 80 DEG C, obtain laminate structure CaTi ₂o ₄(OH) ₄rhombus nanometer sheet.

Claims

1. a laminate structure CaTi ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, is characterized in that, step is as follows:

2. laminate structure CaTi according to claim 1 ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, is characterized in that, step 1) in, the concentration of described ammonia soln is 30%.

3. laminate structure CaTi according to claim 1 and 2 ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, is characterized in that, step 1) in, first stir, then leave standstill 2 ~ 5min.

4. laminate structure CaTi according to claim 3 ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, is characterized in that, step 2) in, in described precursor pulp, the concentration of nitrocalcite is 0.11 ~ 0.165mol/L, and calcium titanium is than being 1.1:1.

5. laminate structure CaTi according to claim 1 ₂o ₄(OH) ₄the preparation method of rhombus nanometer sheet, is characterized in that, step 2) in, described hydro-thermal reaction is carried out in a kettle., and in reactor, compactedness is 30 ~ 80%.

6. the laminate structure CaTi that obtains of a preparation method according to claim 1 ₂o ₄(OH) ₄rhombus nanometer sheet.