TWI261575B - Process for synthesizing nano-powdered sols of visible light responsive TiO2 - Google Patents

Abstract

The present invention provides a manufacturing process for nano-powdered sols of TiO2, which is responsive to visible light, utilizing titanium compound, such as titanium tetrachloride or titanium sulfate. After dilution, ammonium water is used to adjust pH to 7.0-9.0, generating titanium hydroxide. After washing and filtering, appropriate oxidant or acid (including inorganic acid and organic acid) or both, additive, modifier and surfactant (if necessary) are added. Depending on operating conditions, nano-powdered sols of TiO2, which is responsive to visible light, are synthesized, having visible light-responsively photocatalytic property. The products are processed and applied to the surface of object being handled. After baking and drying, the surface of object being handled forms a thin layer with good adsorption, having photocatalytic or self-cleaning property while illuminating by visible light. The products of this invention can appear colorless to golden yellow or yellowish brown sols liquid depending on the type and concentration of additives and also operating conditions thereof. The content of TiO2 ranges from 0.5 to 10% (depending on conditions), and the particle size of nano-powered TiO2 is varied depending on operating conditions. Those nano-powdered particles ranging from 2 to 50 nm in size possess photocatalytic force and multiple efficacy, such as self-cleaning, easy-to-clean, hard-to-pollute, anti-mold, deodorization and fog-resistance.

Description

1261575 玖, invention description: [Technical field to which the invention pertains] The present invention belongs to a photocatalyst under visible light irradiation (

Photo-catalyst or Sel f-cleaning method for synthesizing visible-type titanium dioxide (Ti〇2) nano powder sol. Specifically, the present invention relates to a titanium dioxide powder sol having a nano-meter scale with a visible light photocatalytic activity, which has a particle distribution in the range of 2 to 50 nm, wherein the titanium dioxide content is 0.5. ~10〇/〇〇 [Prior Art] Since the 1970s, we can see a lot of research on the manufacture of semiconductors from titanium dioxide in the academic literature. Most of its contents are based on the existing chemicals (especially titanium dioxide particles), and its photochemical reactions and semiconductor reactions are studied. The crystal structure and particle size can be clearly confirmed, which will obviously affect the reaction. Efficiency; According to the literature, in the anatase or anatase/rutile structure, the particles below (10) are 佺. However, in all papers, there is little talk about the synthesis of titanium dioxide and the specifications of its products. Since the beginning of the year of 1999, titanium dioxide photocatalyst has been highly valued in the application of environmental cleanliness, and in the year of 1997, it entered the practical P "again" but most of its research focused on the development of applied technology, and very little about the mouth ################################################ Yan Jiu. In fact, the 'synthesis method has a great influence on the photocatalytic treatment effect. According to the literature release _ yfa· Unveiled the synthesis method of titanium photocatalyst, mostly 1261575 to make microparticles by chemical method 5 & ,, ^ . The shape of titanium oxide. Although there are many titanium dioxide I k 疋 by grinding and pulverizing method ^, 乍 (the most hanged is the P-25 produced by Degussa company, 4 using grinding pulverization method Manufactured, but the titanium dioxide particles produced by this method have uneven particle size (from 10 to 50 Onm) and the crystal type can be used as a coating/cosmetic/: 'Text 'Use' can not effectively play the role of photocatalyst or surface self-cleaning. Research..., correction 'such as the introduction of ultrasonic shock ultrasonic = or: chemical grinding method into the acid, which can improve particle size and limited use 'For crystallization The configuration of the structure is not obvious, and the effect is limited, and the application range of the finished product remains unchanged. As for the chemical synthesis part, the liquidation is referred to the use of gaseous chemical sediments μ v, although, . Γνη, 丄 儿 儿 ( Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem Chem It is used in mass production. In the liquid synthesis method, it is divided into organic solvent method and aqueous solution method, and water/cold solution method is preferred. The organic agent method is to treat titanium oxide oxide [Ti~oxyalkyl : 4 $ In the solvent, under different heating conditions to form a dioxin powder or a film, this part includes the heat of burning titanium oxide in ethylene glycol as disclosed in the 曰本特开平4_ Kaiping^虎告; The titanium alkoxide is heated in an alcohol amine as disclosed in the 〇37旒 publication:: to a milk: titanium or the like. Since the price of the titanium alkoxide is expensive and the operation is carried out under the back pressure of the door/dish, the method is generally only used for the production of the catalyst for the industrial 1261575 chemical, as for the synthetic method of the taste. For the purpose of use - based on cost considerations, it is not possible to use this method for the synthesis of aqueous solutions, and it is mainly used as a method, including 7] This patent or a Japanese publication includes a special solution for the analysis of juices in a titanium-coated solution. Drilling 丨徭 ^ four gas (four) ... after heating; or special open 6 - said the No. 9 bullet titanium dioxide sol. In the most conditions of this practice, the formation of heat is disadvantageous in the formation of the sol liquid: Erli::, which leads to poor stability of the sol and easy decomposition of the sink. A low-temperature reaction is carried out under the condition that the oxychloride of hydrogen peroxide is added to the aqueous solution, or the low-temperature reaction is carried out for a long time under the condition of adding hydrogen peroxide: pH: 2-6 according to the γ 319 publication. The produced oxidized bismuth:: 广·································································· In the Japanese Patent Publication No. 7-28614, the titanium oxide acid is heated, and the titanium hydroxide aqueous solution is added to hydrogen peroxide at a low temperature to raise the temperature reaction, and the titanium dioxide sol formed has a photocatalytic action, but is limited. In the characteristics of hydrogen peroxide, its concentration is limited to 2% or less, which is troublesome. The most important thing is that the photocatalyst U ultraviolet photocatalyst produced by the above patent does not work for visible light, so it is greatly limited in popularization and application. The Patent No. 135895 of the Republic of China Patent Gazette is based on the addition of an organic acid to an aqueous solution of titanium tetrachloride. The above reaction is carried out to form a sharp Qin mine. The product of the product is crystallized and the particle distribution is compatible with the photocatalyst. Seeking, but the gas content in the solution is very high (l 〇 / liter or more), the stability of the finished product is the main bottleneck. Publication No. 349981 discloses that four titanium carbides are reacted with ammonia water at pH = 2-6, and the precipitate (titanium hydroxide or orthotitanic acid) is filtered and washed 'added at low temperature (5 to 8 ° C). Hydrogen peroxide, long time low temperature mixing, the resulting amorphous titanium dioxide, which revealed nothing to do with the case. Announcement No. 393,342 patent is to heat titanium sulfate to form titanium dioxide, and then add a simple acid (such as nitric acid, etc.) to wash away the residual sulfate and dissolve the titanium dioxide to reduce the particle size. This practice is completely irrelevant to the case. . Patent No. 443,992 is a method of forming a film of titanium dioxide, rather than a method of forming a sol. Similarly, the photocatalysts produced by the above patents are all ultraviolet photocatalysts and do not work for visible light, so they are greatly limited in popularization and application. The inventor of the present invention has previously developed a process for applying a series of process settings to a titanium dioxide sol having a photocatalytic function, and previously filed a patent application (application numbers 〇92122〇34 and 〇92128954), including Five procedures, such as dilution, "mouth, washing, conversion and ripening, make the production of titania sol t of nano-photocatalyst function into a thermochemical process for stability/w I production, and for post-process or treatment The object:: proposes the way of response and the modification process 'but basically still based on ultraviolet light, which also forms a bottleneck in application promotion. Ding = together with the above patent content, it can be found that all synthetic patents are locked in the formation of ultraviolet titanium dioxide sol, and no specific results have been seen in the field of visible light. 1261575 SUMMARY OF THE INVENTION The present invention utilizes washed titanium hydroxide or orthotitanic acid, or dissolves and dilutes a titanium compound in neutral water or an appropriate acid solution by a conventional process (dilution procedure), pH adjustment (Neutralization procedure) and washing (washing procedure) 'After obtaining a solid precipitate of titanium hydroxide or orthotitanic acid, a series of process settings are used to synthesize self-cleaning (not easily stained, easy to clean) and visible light photocatalyst. The function of the nano-sized titanium dioxide powder sol, the particle distribution in the range of 2~5〇nm, wherein the titanium dioxide content is 〇·5~1〇%, the content package will be washed titanium hydroxide or n-dicarboxylic acid or hydrazine Or, after the washing solid precipitate of titanium hydroxide or orthotitanic acid is stirred and mixed uniformly in water, the selected oxidizing agent or acid (including inorganic acid, organic acid) or both, and additives, modifiers, and Depending on the desired surfactant, the conversion is carried out under specific conditions (conversion procedure); and the aging is carried out under different conditions according to the product category, and the titanium dioxide sol (maturation process) is used as a medium function; The liquid is continuously reacted under the set temperature and time conditions to produce a visible light photo-contact pH value, filtered, and then, if necessary, the liquid after the reaction is adjusted to form a finished product. [Embodiment]

Nano-TiO2 sol aqueous solution process with nanometer visible light photocatalyst function, in which the photocatalytic effect can be exerted in the % environment, with a series of process settings, to synthesize the titanium dioxide powder sol process, including 1261575 conversion and ripening Great focus. The conversion process is to put the washed titanium hydroxide or orthotitanic acid filter cake into deionized water, stir and disperse evenly, add oxidant or acid (including inorganic acid, organic acid) or both as needed, and add additives, Modifier and optional surfactant. The oxidizing agent usable in the present invention includes perylene, periodic acid, potassium permanganate, sodium permanganate, nitric acid, etc., and the concentration thereof is from 1 g/liter to 200 g/liter; the inorganic acid used is Including hydrogen iodide, /hydrogenated hydrogen, salt fee, peroxyacid, sulfuric acid, nitric acid, acid, molybdenum, etc., the addition amount is 0.1 ml / liter ~ 12 〇 ml / liter; organic acid is Formic acid, acetic acid, oxalic acid, picric acid, citric acid and tartaric acid are added in an amount of 13⁄4 liter / liter 1 liter / liter; wherein the addition of oxidant or acid can be added for one or only Add one of them, depending on the requirements of the finished product. If the finished product is directly used for spraying or surface, the addition of oxidizing agent is a priority. If the finished product is to be used for film formation or subsequent processing or high concentration is required, it is preferred to add acid or a combination of the two. The type of acid to be added depends on the application target of the finished product (ie, the material to be processed) and environmental considerations. The modifier used is different depending on the treatment target, including tannic acid (

S··ate) Poly-aluminum chloride (PAC), sulphate, sulane, etc.; and the addition amount is preferably liter/liter. The surfactant is added as needed, and the type is preferably between 200~1〇00 in the main knife of polyethanol (EG) or propylene glycol (ppG) or hydrazine (Np) or natural alcohol. The range of additives from 1〇 to 5000ppm 包括 includes iron, copper, zinc, nickel, bismuth, tin, gold, silver 1261575, turning over or #metal oxides, hydroxides, acid salts, carbonates, phosphates, Sulfate or vapor, etc., is added in an amount of 1 mg/liter to 5 g/liter. The modifiers are selected according to the type of application object (ie, the material to be processed), and the natural materials (such as wood, paper, fiber, etc.) are mainly tannic acid, polyaluminum chloride, and alumina 'aluminum sulfate; Glass, metal, stoneware, ceramics, etc. are preferably tannic acid; while man-made fibers or high molecular polymers are mainly made of tannic acid and decane. The conversion reaction is carried out according to the set temperature and time by adding the modifier and the oxidizing agent or the acid or the ortho-titanate solution of the above two. In the present invention, the conversion temperature is 10 to 95 ° C (depending on the additive) The time is at least 1 minute and the stirring speed is maintained at 30 to 300 rpm. After the conversion, the temperature is adjusted to 5 〇 to 9 5 ° C, and the heating is continued for 4 to 72 hours, and the stirring speed is maintained at 3 〇 to 3 rpm to carry out the aging reaction. The matured sol solution is filtered through a filter, packaged and packaged, etc. [Examples] # The following examples are given to illustrate the contents of the present invention, but the scope of the present invention is not limited to such examples. Example 1: Adding deionized water 1 liter in a 20 liter reaction tank, The stirring speed was set at 300 rpm, the reaction tank was kept at 5~1 Torr in an ice water bath, and it was taken to take 500 g of titanium tetrachloride (TlC14) to a metering pump at 4 s liters per minute' (11 1261575 4 ml/ The speed of min ) is continuously added to the water; when it is completely added, stirring is continued for 2 hours (to clear and transparent liquid), then 2% by weight of ammonia water is added at a rate of 1 〇 ml per minute, and the stirring speed is increased to 600 rpm. Continue to observe the change of pH value. When the pH value reaches 4.0, add ammonia water at a rate of 2~4 ml per minute until ρΗ=7·5~8(). After filtering the above solution as a vacuum filter, the white filter cake (containing orthotitanic acid) was placed in a 200-liter washing tank. The tank was filled with tap water or soft water for 1 liter, and the stirring speed was set to 60 rpm. The time is 2 hours (until the mixture is homogeneous) and then filtered. After this filtration is repeated three times, the filter cake can be transferred to the conversion and ripening tank. Put 20 liters of deionized water in the tank, keep the stirring speed at 300 rpm, and continue stirring after adding the filter cake! Hours to make the mixture uniform, then add 50 ml of peracetic acid (Hcl〇4), continue to stir at room temperature for 30 minutes, then add material (25%) 8 〇 ml and silver carbonate i gram ' at a stirring rate of 300 _ Stir for 3 minutes; then raise the temperature to ah, hold it under stirring for 6 hours, cool down, adjust the pH value and then pack. The titanium dioxide sol prepared by the method is a golden yellow transparent aqueous solution, the Qi is in the range of 4 to 9, the titanium dioxide content is about 1%, the particle distribution is 5 to 15 nm, and it is needle-like to flaky crystal, and can be directly used for spray treatment or Post-treatment film formation, can play the role of "self-", decontamination, with the general visible light and traditional light bulbs, can play the deodorization effect 0 Example 2: The treatment steps are the same but in the conversion process, replaced by hydrogen peroxide Gas acid (12 1261575 added 200 ml); replace the tannic acid with multi-evaporized aluminum (10%) in an amount of 1 〇〇 ml; the additive is changed from silver carbonate to gasified stannous, and 3 g in the addition The operating conditions are the same as those in the first embodiment. The obtained titanium dioxide sol solution is a colorless to yellow transparent aqueous solution having a pH of 7 to 9 and a titanium dioxide content of about U. The particles are distributed at about 5 to 2 nm, which is needle-like to flaky crystal. It can be directly used for spray treatment or post-treatment to form a film, which can play the role of self-cleaning and decontamination. 'With the irradiation of visible light, it can exert the effect of sterilization.

The treatment procedure is the same as in the first embodiment, but in the conversion process, the decane i 1 ane is replaced by the oxalate acid, and the rabbit is added to the inside of the rabbit, and the operating condition is the same as the actual obtained titanium dioxide sol liquid. _ Combined with the main vapor color transparent aqueous solution, the pH value of the 'titanium oxide content is 1% left six, the particles of +, ^ ^ are distributed around 5~30nm left, to needle-like to flaky crystal, can be f f mouth is directly used for human w fiber / polymer poly, J gas treatment and after adding the total customer, ^ force / dish after treatment into ", can play a difficult role; long-term and easy to clean the role.

[Simplified illustration] 13

Claims (1)

1261575 Ί V .W— .Jr \ Ί Factory ___ stomach 4 Scope: 1 ^ -#^^^^^(nano-meter (Ph〇t〇.catalyst) method of visible titanium dioxide nano powder sol, The method is to dissolve the compound of Chin in pure water or deionized water or a suitable acid solution or to be called a dilution program, pH adjustment or a neutralization procedure and a washing or washing procedure to obtain chlorine oxidation. Titanium or orthotitanic acid washing_藏,_ The following method at a temperature lower than (10).c, and synthesizing a nanometer visible visible titanium dioxide nano powder sol, including: (1) Conversion procedure: washing hydrogen Titanium oxide or orthotitanic acid, in quantitative pure water or deionized water, the amount of pure water or ionized water used above is 10 to 200 times the weight of titanium hydroxide or orthotitanic acid solid, and after mixing and mixing uniformly An oxidizing agent or an inorganic or organic acid may be added. The amount of the oxidizing agent used is buck/liter, the amount of the inorganic acid added is 1.5 ml/liter, and the amount of the organic acid added is 0.1 mg/liter to 100 mg/liter. And adding a conversion additive, the amount of addition is 丨mg liter 5g _ / liter, And the conversion modifier, the addition amount is 0. 05~75 pen liters / liter, and the surfactant is added in the conversion procedure, the addition amount is 10~5 〇〇〇ppm, and the molecular weight distribution is between 200~3000 , the conversion temperature is maintained at 10~95 ° C, the conversion stirring speed is 30~30 rpm, the conversion time is 1 knive 1 liter, and the conversion procedure is carried out under the specific conditions;) the heating private sequence · the solution after the (1) conversion program The aging reaction can be carried out in the original tank or another heating tank, and the ripening/stirring degree is set to 30 to 3 rpm, the aging temperature is 〇~95 C, and the aging time is 4 to 72 hours. 1261575, if the patent application scope is the first; the method, according to the conversion and curing procedures, if necessary, through the pH σ mouth, filtration and I become the finished product, that is, the nano-sized powder sol is prepared. Titanium 3, as in the scope of the patent application, the oxidizing agent used in the conversion includes perchloric acid biting stone, sulphate, high I, and nitric acid. The method of the invention is the method of the invention, wherein the inorganic acid used for the conversion comprises perchloric acid, tartaric acid, nitric acid, meal, hydrochloric acid, sulfuric acid, hydrogen bromide or moth hydrogen. 5, for example, the method of patenting Capricorn i, wherein the organic acids used in the conversion include acid, acetic acid, oxalic acid, picric acid, citric acid and tartaric acid. 6. The method of claim 1, wherein the conversion additive comprises an oxide, a hydroxide, a citrate or a carbonate of a metal such as iron, copper, rhodium, nickel, ruthenium, tin, gold, silver, molybdenum or ruthenium. , phosphates, acid salts and chlorides. 7. For example, in the method of claim 1, wherein the conversion agent includes a touch (s), a 〇 ( (4), a 〇 - 兀 兀 PA PA PA 氧化 氧化 氧化 S S S S S S S S S S S S S S S S Etc. 8. As in the method of Patent Application No. 1, the surfactant used in the conversion in # includes polyethylene glycol (PEG) or polypropylene glycol (ppg) or mercapto g (Np) or natural alcohol.