CN103521205A - A method for preparing high photocatalytic activity core-shell structure TiO2 material - Google Patents

Abstract

Translated fromChinese

本发明涉及一种制备高光催化活性核壳结构TiO₂材料的方法，通过超声、加热或微波处理晶态TiO₂材料（如商业二氧化钛纳米材料P25）的悬浮液，一步将其转换成具有晶体内核和无定型壳层的核壳结构TiO₂材料。反应过程中，反应物TiO₂材料表面吸附溶剂中的羟基，在超声、加热或微波的作用下，TiO₂晶体表面部分Ti⁴⁺被还原成Ti³⁺，同时在表面形成一个非晶态壳层。本发明操作方法简单新颖可行，不利用其他贵重金属元素，对环境无污染，耗能低，绿色环保、生产成本低，具有比未处理的晶态TiO₂材料高数倍到数十倍的光催化分解水制备氢气和光催化降解有机污染物的活性，具有商业规模化生产潜力。

The present invention relates to a method for preparing a highly photocatalytically active core-shell structure_TiO2 material, by ultrasonically, heating or microwave treating a suspension of crystalline_TiO2 material (such as commercial titanium dioxide nanomaterial P25) to convert it into one with a crystalline core in one step and amorphous shell core-shell structure TiO₂ materials. During the reaction process, the reactant TiO₂ material surface adsorbs hydroxyl groups in the solvent, and under the action of ultrasound, heating or microwave, Ti⁴⁺ on the surface of TiO₂ crystals is reduced to Ti³⁺ , and an amorphous shell is formed on the surface layer. The operation method of the present invention is simple, novel and feasible, does not use other precious metal elements, has no pollution to the environment, low energy consumption, green environmental protection, low production cost, and has a light intensity several to dozens of times higher than that of untreated crystalline_TiO2 materials. The activity of catalytic water splitting to produce hydrogen and photocatalytic degradation of organic pollutants has the potential of commercial scale production.

Description

A kind of highlight catalytic active nucleocapsid structure TiO for preparing 2the method of material

Technical field

The present invention relates to a kind of highlight catalytic active nucleocapsid structure TiO for preparing₂the method of material, belongs to nano inorganic material and actinic material field.

Background technology

TiO₂in photochemistry field, there is application very widely, especially, in photochemical catalyst, be subject to the attention of numerous researchers.Along with the development of 21 century economy, environment and energy bottleneck problem more become outstanding, and it is more urgent that the research of environmentally friendly shaped material and new forms of energy also becomes.In all energy, hydrogen is as unique pollution-free reproducible energy, the energy that after the non-renewable energies such as oil, coal and natural gas that continue beyond doubt, a new generation is widely adopted.Hydrogen Energy specific energy density is high, and the product of burning is water, can not produce environmental pollution.

At numerous catalysis materials, (comprise ZnO, SnO₂, WO₃deng oxide and CdS, ZnS sulfides) in, TiO₂have nontoxic, stable performance, cheap, highlight catalytic active can decomposition goal thing etc. feature, be considered to a kind of good photochemical catalyst, be widely used in photocatalysis, light reaction variable color, photovoltage and electrochromics field.Effectively utilize the energy crisis that clean, safe and abundant solar energy can not only solve facing mankind, and will solve day by day serious problem of environmental pollution.

TiO₂the practical subject matter of base optic catalytic material is: TiO₂forbidden band is wider, and the efficiency of light energy utilization is lower, and the absorption of sunshine is confined to ultra-violet (UV) band, and the efficiency of light energy utilization is less than 3%.For this problem, domestic and international researcher has done a large amount of research work, by exploring catalytic process mechanism, has developed multiple method of modifying, to TiO₂carry out modification, comprise reduction Ti(IV) generate Ti(III), all expansion in various degree TiO₂photoresponse scope, improved its visible light photocatalysis active.But correlation technique relates to high temperature, high pressure, consuming time longer, needs the unfavorable factors such as precious metal.

Summary of the invention

The defect existing for prior art, the object of this invention is to provide a kind of highlight catalytic active nucleocapsid structure TiO for preparing₂the method of material.Utilize a kind of method of operating of simple possible, by TiO₂plane of crystal part Ti⁴⁺be reduced into Ti³⁺, form one deck amorphous state simultaneously, obtain having the TiO of high catalytic activity₂catalyst material.

For achieving the above object, the present invention adopts following technical scheme:

A kind of highlight catalytic active nucleocapsid structure TiO for preparing₂the method of material, by ultrasonic, heating or microwave treatment crystalline state TiO₂the suspension of material, a step converts thereof into the nucleocapsid structure TiO with crystal kernel and unformed shell₂material; There is following preparation process and step: by reactant crystalline state TiO₂even with solvent, reaction system is solid phase-liquid-phase system, and reaction system is carried out to ultrasonic, heating or microwave treatment; In course of reaction, reactant TiO₂hydroxyl in material surface adsorption solvent, under the effect of ultrasonic, heating or microwave, TiO₂plane of crystal part Ti⁴⁺be reduced into Ti³⁺, form one deck amorphous state simultaneously, obtain having high catalytic activity nucleocapsid structure TiO₂material.

Described solvent is that pH value is 3 ~ 14 the aqueous solution or alcoholic solution or its mixed solution.

Reactant feed adopts crystalline state TiO₂material (as business titanium dioxide nano material P25, being to utilize anatase that vapour deposition process obtains and rutile to take the mixed crystal that 80:20 is ratio, excellent performance).In preparation process, just utilize some simple solvents, some heavy metal ion of not adulterating reach modification object.Therefore after modification, still keep pollution-free, environmental protection excellent specific property.The nucleocapsid structure TiO obtaining₂photocatalyst material, has unformed amorphous state shell and coated crystallization TiO₂kernel, before and after reaction, particle diameter is without obvious change.After reaction, color is become the dark colours such as lark from white, has the features such as oxygen room and trivalent titanium ion simultaneously, and visible region is widened by ultraviolet region in extinction region, has greatly improved light utilization efficiency, has very outstanding catalytic activity simultaneously.

Compared with prior art, the present invention has following outstanding substantive distinguishing features and significant advantage:

The present invention adopts the simple operations modes such as microwave technology, ultrasonic technique and direct baking oven heating in preparation process; in conjunction with solid phase-liquid phase reactor; method of operating is very simple novel feasible; do not utilize other precious metal elements; environmentally safe; consume energy low, environmental protection, production cost are low, have commercial size productive potentialities.

Accompanying drawing explanation

Fig. 1 is gained nucleocapsid structure TiO of the present invention₂high power transmission electron microscope (HR-TEM) the photo figure of photocatalyst material.

Fig. 2 is gained nucleocapsid structure TiO of the present invention₂electron paramagnetic resonance power spectrum (EPR) analysis chart of photocatalyst material.

Fig. 3 is gained nucleocapsid structure TiO of the present invention₂the photocatalysis hydrogen production performance map of photocatalyst material.

Fig. 4 is gained nucleocapsid structure TiO of the present invention₂the photocatalytic degradation rhodamine B performance comparison figure of photocatalyst material and untreated P25.

Fig. 5 is that the present invention processes gained nucleocapsid structure TiO under condition of different pH₂the photocatalytic degradation rhodamine B performance comparison figure of photocatalyst material and untreated P25.

Fig. 6 is that the present invention uses ethylene glycol solution microwave treatment P25 gained nucleocapsid structure TiO₂the photocatalytic degradation rhodamine B performance comparison figure of photocatalyst material and untreated P25.

Fig. 7 is that the present invention uses the aqueous solution and the ultrasonic processing of ethanolic solution P25 gained nucleocapsid structure TiO₂the photocatalytic degradation rhodamine B performance comparison figure of photocatalyst material and untreated P25.

Fig. 8 is that the present invention uses the aqueous solution and volume fraction 50% ethanol water high-temperature heat treatment P25 gained nucleocapsid structure TiO₂the photocatalytic degradation rhodamine B performance comparison figure of photocatalyst material and untreated P25.

The specific embodiment

After now specific embodiments of the invention being discussed in.

embodiment 1

Process and step in the present embodiment are as follows:

By P25 mass concentration, be the P25 that 1 mg/ ml weighs 50 mg, measure deionized water 50 ml, mix.Mixed liquor is put into 30 seconds of micro-wave oven microwave treatment, and cooling rear centrifugal drying, obtains having very highly active nucleocapsid structure TiO₂photocatalyst material.This material is carried out to structure and performance characterization, and the high-resolution-ration transmission electric-lens that Fig. 1 is resulting materials (HRTEM) is schemed, and can clearly see the nucleocapsid structure of crystalline nucleation in shell amorphous from figure.Fig. 2 is electron paramagnetic power spectrum (EPR) figure, and wherein P25 is untreated business titanium dioxide P25, m-TiO₂for this method, process the material obtaining, from figure, can be clear that the difference of the two, and m-TiO₂the peak type and the peak position that occur are Ti³⁺characteristic peak, proved Ti³⁺existence.Fig. 3 is photocatalysis hydrogen production performance test, and wherein P25 is untreated business titanium dioxide P25, m-TiO₂for the inventive method is processed the material obtaining, the relatively untreated P25 hydrogen manufacturing performance of material that as can be seen from the figure this method processing obtains is significantly improved.Fig. 4 is the performance test of photocatalytic degradation rhodamine B, and wherein P25 is untreated business titanium dioxide P25, m-TiO₂for this method is processed the material obtaining, the relatively untreated P25 light degradation property of material that as can be seen from the figure this method processing obtains is significantly improved.

embodiment 2

By P25 mass concentration, be the P25 that 1 mg/ ml weighs 50 mg, measure respectively deionized water 50 ml, mix, and regulate pH of mixed to be respectively 4.8,6.7,9.1.Mixed liquor is put into micro-wave oven microwave treatment 1 minute, cooling rear centrifugal drying.Different: to regulate aqueous solution pH to be respectively 4.8,6.7,9.1.Resulting materials is carried out to performance characterization.Fig. 5 is the performance test that different pH process photocatalytic degradation rhodamine B, and wherein P25 is untreated business titanium dioxide P25, m-TiO₂for this method is processed the material obtaining.As can be seen from the figure under different pH, process the relatively untreated P25 performance of material light catalysis property obtaining and be significantly improved, and increase with pH rising catalytic degradation activity.

embodiment 3

By P25 mass concentration, be the P25 that 1 mg/ ml weighs 50 mg, measure ethylene glycol 50 ml, mix, mixed liquor is put into micro-wave oven microwave treatment 1 minute, cooling rear centrifugal drying.The performance test of Fig. 6 photocatalytic degradation rhodamine B, the relatively untreated P25 catalytic performance of P25 that ethylene glycol is processed is as we can see from the figure significantly improved.

embodiment 4

By P25 mass concentration, be the P25 that 0.5mg/ ml weighs respectively 25 mg, measure deionized water 50 ml and ethanol 50ml, mix respectively, by the ultrasonic processing of the mixed solution obtaining a hour, centrifugal rear dry.The bi-material that ultrasonic method is obtained carries out performance characterization.The performance test of this bi-material of Fig. 7 and untreated P25 photocatalytic degradation rhodamine B, as can be seen from the figure adopts the method to process the TiO obtaining₂the relatively untreated P25 catalytic activity of material is significantly improved.

embodiment 6

By P25 mass concentration, be the P25 that 0.25mg/ ml weighs respectively 25 mg, the ethanol water 100ml that measures deionized water 100ml and volume fraction 50% mixes with it respectively, after mixing in 180 ℃ of baking ovens heat treatment 3h, cooling rear centrifugal drying.Fig. 8 is the performance test of this bi-material and untreated P25 photocatalytic degradation rhodamine B, as can be seen from the figure adopts the method to process the TiO obtaining₂the relatively untreated P25 catalytic activity of material is significantly improved.

Claims (3)

Translated fromChinese

1.一种制备高光催化活性核壳结构TiO₂材料的方法，其特征在于，通过超声、加热或微波处理晶态TiO₂材料的悬浮液，一步将其转换成具有晶体内核和无定型壳层的核壳结构TiO₂材料；具有以下制备过程和步骤：将反应物晶态TiO₂与溶剂混合均匀，反应体系为固相-液相体系，对反应体系进行超声、加热或微波处理；反应过程中，反应物TiO₂材料表面吸附溶剂中的羟基，在超声、加热或微波的作用下，TiO₂晶体表面部分Ti⁴⁺被还原成Ti³⁺，同时形成一层非晶态，得到具有高催化活性核壳结构TiO₂材料。1. A method for preparing highly photocatalytically active core-shell structure TiO₂ materials, characterized in that, through ultrasonication, heating or microwave treatment of the suspension of crystalline TiO₂ materials, it is converted into a layer with a crystalline core and an amorphous shell in one step The core-shell structure_TiO2 material; has the following preparation process and steps: mix the reactant crystalline_TiO2 with the solvent evenly, the reaction system is a solid-liquid phase system, and the reaction system is subjected to ultrasonic, heating or microwave treatment; the reaction process In this process, the reactant TiO₂ material surface adsorbs hydroxyl groups in the solvent, under the action of ultrasound, heating or microwave, Ti⁴⁺ on the surface of TiO₂ crystals is reduced to Ti³⁺ , and a layer of amorphous state is formed at the same time, resulting in a high Catalytically active core-shell structured_TiO2 materials.2.根据权利要求1所述的制备高催化活性核壳结构TiO₂材料的方法，其特征在于，所述反应物晶态TiO₂材料为商业TiO₂材料P25。2. The method for preparing highly catalytically active core-shell structure TiO₂ material according to claim 1, characterized in that, the reactant crystalline TiO₂ material is commercial TiO₂ material P25.3.根据权利要求1所述的制备高催化活性核壳结构TiO₂材料的方法，其特征在于，所述溶剂为pH值为3~14的水溶液或醇溶液或其混合溶液。3. The method for preparing a highly catalytically active core-shell structure_TiO2 material according to claim 1, wherein the solvent is an aqueous solution or an alcoholic solution or a mixed solution thereof with a pH value of 3 to 14.

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