TiO2-SiO2 compound aerogel and its preparation method

Abstract

The invention provides a TiO2-SiO2 composite aerogel and a preparation method of the TiO2-SiO2 composite aerogel. The Ti / Si molar ratio of the TiO2-SiO2 composite aerogel is ranging from 1:10 to 10:1, the density thereof is 0.1-0.35 g / cm<3>, the porosity thereof is 84-94%, the aperture thereof is 5.0-20.0nm, the pore volume thereof is 1.0-5.0cm<3> / g and the specific surface thereof is 500-1200m<2> / g. The preparation method mainly comprises the steps that modifier consisting of alcohols, silanes and alkanes reagent is used for carrying out the modification and solvent replacing disposal. The TiO2-SiO2 composite aerogel of the invention has the advantages of low density, large specific surface, high pore volume and high porosity; the porosity can achieve 84-94%; the preparation method of the TiO2-SiO2 composite aerogel adopted by the invention adopts cheap and easily gained raw material TiCl4 and industrial water glass and can reduce the production cost; furthermore, the normal-pressure dry-process is convenient and feasible, and suitable for large-scale industrialization production and application.

Description

technical field

[0001] The present invention relates to TiO with high pore volume and high specific surface area 2 -SiO 2 A method for preparing a composite airgel by normal-pressure drying. Background technique

[0002] Titanium dioxide (TiO 2 ) Photocatalytic materials have the advantages of strong oxidation ability, high photocatalytic activity, good chemical and optical stability, etc., and have broad application prospects in solar cells, organic pollutant treatment, sterilization and other environmental protection fields. Especially in recent years, nano-TiO 2 People pay more and more attention to the research and application in environmental protection fields such as air purification and water purification. Like other catalytic materials, TiO 2 Photocatalytic materials need to have a large specific surface area; in addition, the porous structure can endow the material with high adsorption, and the synergistic effect of adsorption / photocatalysis can effectively eli...

Examples

Embodiment 1

[0040] Preparation of TiO with Ti / Si (molar ratio)=2:1 2 -SiO 2 Composite airgel:

[0041] ① Preparation of TiCl 4 Aqueous and silicic acid solutions:

[0042] Using titanium tetrachloride as the titanium source, put 50g of ice cubes into a large beaker in a fume hood, slowly drop 25.4ml of titanium tetrachloride onto the ice cubes, and stir thoroughly for 1 hour after the ice cubes have completely melted. TiCl will be obtained 4 After the aqueous solution is suction filtered to remove impurities, TiCl with a concentration of 3 mol / L is obtained 4 aqueous solution;

[0043] Get 10ml industrial water glass (modulus=3.38, m SiO 2 %=26%, ρ=1.37g / ml) is mixed with 40ml deionized water, after stirring evenly, carry out ion exchange by strongly acidic styrene cation exchange resin, obtain the silicic acid of pH=2~3;

[0044] ② Preparation of TiO 2 -SiO 2 Composite sol

[0045] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magne...

Embodiment 2

[0055] Preparation of TiO with Ti / Si (molar ratio)=1:1 2 -SiO 2 Composite airgel:

[0056] ① Preparation of TiCl 4 Aqueous solution and silicic acid solution: with embodiment 1 step 1.;

[0057] ② Preparation of TiO 2 -SiO 2 Composite sol

[0058] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magnetic stirring, 4ml TiCl 4 The aqueous solution is slowly added dropwise to 10ml of silicic acid, and stirred for 1h to obtain TiO with Ti / Si (molar ratio) = 1:1. 2 -SiO 2 Composite sol;

[0059] ③ The sol is aged to form a composite gel;

[0060] TiO 2 -SiO 2 Pour the sol into a small cylindrical box and place it in a 60°C water bath for aging, and form a block gel after gelling;

[0061] ④Modification and solvent replacement of composite gel:

[0062] a. The composite gel was aged for 24 hours;

[0063] b. Treat the composite gel with the modifier for 72 hours, and replace the modifier solution every 24 hours. The modifier is...

Embodiment 3

[0068] Preparation of TiO with Ti / Si (molar ratio)=3:1 2 -SiO 2 Composite airgel:

[0069] ① Preparation of TiCl 4 Aqueous solution and silicic acid solution: with embodiment 1 step 1.;

[0070] ② Preparation of TiO 2 -SiO 2 Composite sol

[0071] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magnetic stirring, 12mlTiCl 4 The aqueous solution is slowly added dropwise to 10ml of silicic acid, and stirred for 1h to obtain TiO with Ti / Si (molar ratio) = 3:1. 2 -SiO 2 Composite sol;

[0072] ③ The sol is aged to form a composite gel;

[0073] TiO 2 -SiO 2 Pour the sol into a small cylindrical box and place it in a 60°C water bath for aging, and form a block gel after gelling;

[0074] ④Modification and solvent replacement of composite gel:

[0075] a. The composite gel was aged for 24 hours;

[0076] b. Treat the composite gel with the modifier for 72 hours, and replace the modifier solution every 24 hours. The modifier is...

technical field

[0001] The present invention relates to TiO with high pore volume and high specific surface area 2 -SiO 2 A method for preparing a composite airgel by normal-pressure drying. Background technique

[0002] Titanium dioxide (TiO 2 ) Photocatalytic materials have the advantages of strong oxidation ability, high photocatalytic activity, good chemical and optical stability, etc., and have broad application prospects in solar cells, organic pollutant treatment, sterilization and other environmental protection fields. Especially in recent years, nano-TiO 2 People pay more and more attention to the research and application in environmental protection fields such as air purification and water purification. Like other catalytic materials, TiO 2 Photocatalytic materials need to have a large specific surface area; in addition, the porous structure can endow the material with high adsorption, and the synergistic effect of adsorption / photocatalysis can effectively eli...

Examples

Embodiment 1

[0040] Preparation of TiO with Ti / Si (molar ratio)=2:1 2 -SiO 2 Composite airgel:

[0041] ① Preparation of TiCl 4 Aqueous and silicic acid solutions:

[0042] Using titanium tetrachloride as the titanium source, put 50g of ice cubes into a large beaker in a fume hood, slowly drop 25.4ml of titanium tetrachloride onto the ice cubes, and stir thoroughly for 1 hour after the ice cubes have completely melted. TiCl will be obtained 4 After the aqueous solution is suction filtered to remove impurities, TiCl with a concentration of 3 mol / L is obtained 4 aqueous solution;

[0043] Get 10ml industrial water glass (modulus=3.38, m SiO 2 %=26%, ρ=1.37g / ml) is mixed with 40ml deionized water, after stirring evenly, carry out ion exchange by strongly acidic styrene cation exchange resin, obtain the silicic acid of pH=2~3;

[0044] ② Preparation of TiO 2 -SiO 2 Composite sol

[0045] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magne...

Embodiment 2

[0055] Preparation of TiO with Ti / Si (molar ratio)=1:1 2 -SiO 2 Composite airgel:

[0056] ① Preparation of TiCl 4 Aqueous solution and silicic acid solution: with embodiment 1 step 1.;

[0057] ② Preparation of TiO 2 -SiO 2 Composite sol

[0058] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magnetic stirring, 4ml TiCl 4 The aqueous solution is slowly added dropwise to 10ml of silicic acid, and stirred for 1h to obtain TiO with Ti / Si (molar ratio) = 1:1. 2 -SiO 2 Composite sol;

[0059] ③ The sol is aged to form a composite gel;

[0060] TiO 2 -SiO 2 Pour the sol into a small cylindrical box and place it in a 60°C water bath for aging, and form a block gel after gelling;

[0061] ④Modification and solvent replacement of composite gel:

[0062] a. The composite gel was aged for 24 hours;

[0063] b. Treat the composite gel with the modifier for 72 hours, and replace the modifier solution every 24 hours. The modifier is...

Embodiment 3

[0068] Preparation of TiO with Ti / Si (molar ratio)=3:1 2 -SiO 2 Composite airgel:

[0069] ① Preparation of TiCl 4 Aqueous solution and silicic acid solution: with embodiment 1 step 1.;

[0070] ② Preparation of TiO 2 -SiO 2 Composite sol

[0071] Regulate the pH=6 of gained silicic acid with the NaOH aqueous solution of 1.0mol / L, under magnetic stirring, 12mlTiCl 4 The aqueous solution is slowly added dropwise to 10ml of silicic acid, and stirred for 1h to obtain TiO with Ti / Si (molar ratio) = 3:1. 2 -SiO 2 Composite sol;

[0072] ③ The sol is aged to form a composite gel;

[0073] TiO 2 -SiO 2 Pour the sol into a small cylindrical box and place it in a 60°C water bath for aging, and form a block gel after gelling;

[0074] ④Modification and solvent replacement of composite gel:

[0075] a. The composite gel was aged for 24 hours;

[0076] b. Treat the composite gel with the modifier for 72 hours, and replace the modifier solution every 24 hours. The modifier is...

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