KR101877124B1 - First Synthesis of Uniformly Ordered Mesoporous TiO2-B and Its Optical and Photocatalytic Properties - Google Patents

Abstract

The present invention relates to a TiO ₂ -B crystal characterized by having ordered ordered mesoporous structure; TiO ₂ -B structures characterized in that the framework is crystalline or amorphous while structurally regular six-electron system channels are formed; A method of making a crystalline or amorphous TiO ₂ -B structure having ordered ordered mesoporous structure; And to the above uses.

Description

[0001] The present invention relates to a method for synthesizing uniformly structured mesoporous TiO2-B and its photochemical photocatalytic properties,

The present invention relates to a TiO ₂ -B crystal characterized by having ordered ordered mesoporous structure; TiO ₂ -B structures characterized in that the framework is crystalline or amorphous while structurally regular six-electron system channels are formed; A method of making a crystalline or amorphous TiO ₂ -B structure having ordered ordered mesoporous structure; And its use.

Porous metal oxides have been used as electrode materials in the energy field. Generally, the electrode material should have both good electronic conductivity and ionic conductivity. In general electrode materials, ionic conductivity is lower than electron conductivity. However, in the case of a porous electrode material, it is possible to transfer ions to the interior of the particle, thereby substantially reducing the ion movement path. It is possible to achieve similar effects to the porous electrode material by using a nano material which exhibits the same effect. However, since the contact resistance between particles is high and it is difficult to manufacture the electrode, it is difficult to apply it.

On the other hand, TiO ₂ is one of the most important metal oxides that are most widely used industrially and academically. TiO ₂ is known to have four phases: a stable brookite phase, an anatase phase, a stable rutile phase at high temperature, and a TiO ₂ ( B). The crystal structure of rutile has a disadvantage in that the adsorbing ability of the reactant is smaller than that of the crystal structure of the anatase phase and the photocatalyst activity is not superior to that of the anatase crystal due to the slow recombination rate of electrons and holes generated by light .

Of the 11 different phases TiO2-B is unique in that it has crystalline voids that allow easy intercalation of small cations. Thus, coupled with the fact that Ti (IV) in TiO2 can easily be reduced to Ti (III), TiO2-B has received a great deal of attention recently as a potential electrical energy storage material. In addition, TiO2-B can be used as an electrode material for dye sensitized solar cells, supercapacitors, and smart window applications. In addition, due to its structural openness, the photocatalytic activity for hydrogen production and dye decomposition is higher than for other phases. In this respect, there have been many efforts to develop methods for synthesizing TiO ₂ -B in various forms over the last 25 years.

However, no method for producing a uniformly ordered mesoporous form (Figs. 1a, 1b) has been developed.

TiO ₂ -B may have a much higher performance as an electrical energy storage material and as a photocatalyst if it has a structured regular mesopore structure rather than a nanoparticle.

It is therefore an object of the present invention, preferably evenly, to provide a structure of a regular meso pores _{TiO 2 -B (uniformly ordered mesoporous TiO} 2 -B, uom -TiO 2 -B).

A first aspect of the present invention provides a TiO ₂ -B crystal characterized by having ordered ordered mesoporous structure.

A second aspect of the present invention provides a TiO ₂ -B structure wherein the framework is crystalline or amorphous while structurally ordered hexagonal channels are formed.

A third aspect of the present invention is a method of making a crystalline or amorphous TiO ₂ -B structure having ordered ordered mesoporous, wherein the Ti source, the mesopore-directing agent, the acid catalyst and the solvent A step A of preparing a precursor solution containing the precursor solution; As a step of evaporating the solvent from the precursor solution, the mesoporous-inducing agent and the hydrolyzed Ti source undergo self-assembly, whereby a structured regular mesopore is formed in the titanium oxide by the mesoporous-inducing agent, B in which the mesoporous-inducing agent forms a filled and agglomerated titanium oxide structure; A step C for carbonizing the mesopore-inducing agent filled in the structured regular mesopores; And including the step D of removing carbonized aggregates filled the structural regular meso pore, provides a process for the production of TiO ₂ -B structure.

A fourth aspect of the present invention is a TiO ₂ -B crystal having ordered ordered mesoporous structure according to the first aspect, or a structure in which structural regular tetragonal channels are formed according to the second aspect, Characterized in that it contains a TiO ₂ -B structure that is crystalline or amorphous.

A fifth aspect of the present invention is a TiO ₂ -B crystal having ordered ordered mesoporous structure according to the first aspect, or a structure having regularly arranged six-valence channels according to the second aspect, Characterized in that it contains a TiO ₂ -B structure which is crystalline or amorphous.

A sixth aspect of the present invention is a TiO ₂ -B crystal having ordered ordered mesoporous structure according to the first aspect or a structure in which structural regular tetragonal channels are formed according to the second aspect, There is provided a process for producing hydrogen from water in the presence of a photocatalyst containing a TiO ₂ -B structure which is crystalline or amorphous.

Hereinafter, the present invention will be described in detail.

The present inventors have for the first time, a regular structure 6 _{uom -TiO 2 -B (h- uom -TiO} 2 -B) to room politics, especially at a high purity and large scale (> 10 g), were synthesized, h - uom - TiO ₂ -B exhibits much higher performance during photocatalysis when decomposing 4-chlorophenol (4-CP) and methylene blue (MB) when producing hydrogen from methanolic water , the band gap energy of h - uom - TiO ₂ - B was reduced by 0.36 eV compared with its nanoparticles. The present invention is based on this.

Until recently, only the anatase among the four TiO ₂ phases was prepared in the form of uom - anatase, and its physicochemical properties were determined. In this respect, the present invention is important in that it first presents h-uom- TiO ₂ -B synthesis and its physico-chemical property characterization.

The TiO ₂ -B crystal according to the present invention is characterized by having an ordered mesoporous structure having a regular structure like a hexagonal system.

The present invention also provides a TiO ₂ -B structure in which the framework is crystalline or amorphous while structurally ordered hexagonal channels are formed. At this time, a surfactant or carbonized carbon may be filled or removed in the hexagonal system channel. Further, the thickness of the skeleton forming the mesoporous pores may be 3 to 500 nm nanoscale.

On the other hand, uniformly ordered mesoporous form ( uom- TiO ₂ -B, Figs. 1a and 1b) uniformly and structurally according to the present invention can be applied as an electric energy storage material and / (Randomly ordered mesoporous forms, rom- TiO ₂ -B, Fig. 1c) and individual nanoparticle forms ( np- TiO ₂ -B, Fig. 1d) First, the diffusion rate of ions and molecules in uom -TiO ₂ -B is uniform (uniform diffusion rate) due to the uniformity of the channel size through the TiO ₂ material. Second, because the decrease rate of diffusion of ions and molecules are due to the channel size variation, the diffusion rate of the ions and molecules inserted into the uom -TiO ₂ -B is faster than rom -TiO ₂ -B (faster diffusion rate) . Third, due to the complete openness of the channel from all entrance sites, unlike rom- TiO ₂ -B, all sites in uom -TiO ₂ -B are allowed to intercalate ions and molecules (Full site acceptability). Fourth, TiO ₂ -B due to the three-dimensional crystalline interconnecting wall, in the rom -TiO uom -TiO ₂ -B ₂ -B than in, or along the walls of the skeleton TiO ₂ -B carrier moving speed is faster ( Faster carrier movement depending on the skeleton). Fifth, the optical and electrical properties of the TiO ₂ -B wall or framework are constant within the uom -TiO ₂ -B (constant optical and electrical properties), because the thickness of the wall or framework within the material is constant. Sixth, the absorption onset of uom -TiO ₂ -B is red-shifted than that of np -TiO ₂ -B, as observed in uniformly aligned mesoporous anatase, It helps to enhance the photocatalytic activity of uom -TiO ₂ -B when applied to various photocatalysts (low band gap).

TiO ₂ -B with ordered mesoporous structure according to the present invention can be used for evaporation-induced self-assembly (EISA) and combined assembly of soft and hard template methods. soft and hard (CASH) template methods.

Thus, a method of making a crystalline or amorphous TiO ₂ -B structure having ordered ordered mesoporous structure according to a third aspect of the present invention,

A preparation of a precursor solution containing a Ti source, a mesopore-directing agent, an acid catalyst and a solvent;

As a step of evaporating the solvent from the precursor solution, the mesoporous-inducing agent and the hydrolyzed Ti source undergo self-assembly, whereby a structured regular mesopore is formed in the titanium oxide by the mesoporous-inducing agent, B in which the mesoporous-inducing agent forms a filled and agglomerated titanium oxide structure;

A step C for carbonizing the mesopore-inducing agent filled in the structured regular mesopores; And

Structure D includes the step of removing the carbonized aggregates filled in the regular mesopore.

In step A, the Ti source may be selected from the group consisting of oxides, chlorides, acetates, fatty acid salts, phosphonates, thiolates, and alkoxides of Ti, but is not limited thereto. For example, non-limiting examples of the Ti source include titanium- (n) butoxide, titanium- (n) ethoxide, titanium- (n) isopropoxide, titanium- (n) propoxide, titanium tetraisopropoxide and the like side and TiCl _4.

Structural directing agents act as templates for certain crystalline structures. Charge distribution, size and geometric shape of structure directing agents provide structure directing properties.

The mesoporous-inducer is a kind of structure directing agent, Neutral, anionic, cationic surfactant. For example, an alkylamine-based or ammonium alkyl halide-based surfactant can be used. For example, in the above alkylamine-based or ammoniumalkyl halide-based surfactants, the alkyl group may be a linear or branched alkyl group having 4 to 24 carbons. Specifically, a trialkylammonium alkyl halide such as tri (C1-6 alkyl) ammonium C10-30 alkyl bromide may be used as the ammonium alkyl halide surfactant. For example, CTAB (cetyltrimethylammonium bromide) But is not limited thereto.

In this example, HO (CH ₂ CH ₂ O) ₂₀ (CH ₂ CH (CH ₃ ) O) ₇₀ (CH ₂ CH ₂ O) ₂₀ H (Pluronic P123) was used and Pluronic P123 was a kind of neutral surfactant .

The non-limiting concentration range of the mesoporous-inducing agent in the precursor solution is 0.01 mol to 1 mol, preferably 0.1 mol to 0.5 mol.

The acid catalyst may be an inorganic acid or an organic acid, and non-limiting examples of the inorganic acid include hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, halogenated silane, and mixtures thereof. Non-limiting examples of the organic acid include acetic acid, chloroacetic acid, Such as dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycollic acid, maleic acid, malonic acid, toluenesulfonic acid, oxalic acid, and the like. The acid catalyst is preferably hydrochloric acid, sulfuric acid, phosphoric acid, or a mixture thereof.

The acid catalyst serves to control the rapid hydrolysis and condensation rate of the metal oxide precursor. Further, the dispersion and viscosity can be controlled by preventing the aggregation of the metal-containing particles due to the hydrogen ions (H ⁺ ) of the acid catalyst.

It has been found for the first time in the present invention that by regulating the type and mixing ratio of the acid catalyst used in Step A, it is possible to form a structurally regular mesoporous substance in the titanium oxide by the mesoporous-inducing agent. Therefore, the kind of the acid catalyst and the mixing ratio are not limited as long as the mesoporous-inducing agent can form a structural regular mesopore in the titanium oxide. When a mixture of sulfuric acid and hydrochloric acid is used as an acid catalyst, a structural regular mesopore can be formed in the titanium oxide by a mesoporous-inducing agent in sulfuric acid: hydrochloric acid = 1: 0.1 to 10.

The solvent is water or a hydrophilic organic solvent. Nonlimiting examples of the hydrophilic organic solvent include lower aliphatic alcohols such as methanol, ethanol, isopropanol (IPA), n-butanol and isobutanol, ethylene glycol such as ethylene glycol, ethylene glycol monobutyl ether and ethylene glycol monoethyl ether Derivatives thereof, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, diacetone alcohol and the like. Further, one or more selected from the group consisting of these can be used. Further, one or more of toluene, quinilene, hexane, ethyl heptanoate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime and the like may be used in combination with these hydrophilic organic solvents.

Step B is a step of slowly evaporating the solvent from the precursor solution, which is evaporation-induced self-assembly (EISA). During the EISA step, the mesoporous-inducing agent and the hydrolyzed Ti source undergo self-assembly, forming mesopores in the amorphous TiO 2 by the mesoporous-inducing agent, and mesoporous-inducing agents packed in the mesoporous aggregates.

The Ti oxide precursor slowly undergoes hydrolysis and polycondensation at low pH by sol - gel synthesis. The inorganic material may be subjected to a maturing process, followed by heat treatment to remove the mesoporous-inducing agent and residues and improve the crystallinity.

The temperature of step B varies depending on the solvent used but can be carried out at a temperature of 25 to 40 ° C.

The reaction time can vary from 0.5 hour to 20 days. The reaction time is preferably 2 hours to 15 days, more preferably 20 to 50 hours.

When all the solvent has evaporated, the remaining solids can be dried.

Step C is the step of carbonizing (CBN) the mesoporous-inducer agglomerates filled in mesopores into mechanically harder carbon agglomerates. The carbonization is preferably carried out in a nitrogen atmosphere.

The temperature of the heat treatment at the time of carbonization differs depending on the mesoporous-inducing agent used, and the temperature of carbonization as long as it can carbonize the mesoporous-derivative is not particularly limited.

The temperature of the C stage may be 200 to 700 ° C.

The step D for removing the carbonized agglomerates filled in the regular mesopore can be carried out usually in the air or in the presence of oxygen, and the reaction temperature is not particularly limited as long as it can remove the carbonized mesopore-derivative.

When the carbonized agglomerates in the mesopores are removed by the heat treatment, not only the crystallinity of the Ti oxide can be further improved, but the Ti oxide can be calcined, resulting in a more stable structure.

According to the present invention, TiO ₂ -B having a structured regular mesopore like a six-sided structure can be produced by the following non-limiting method.

To the ethanol solution (300 g) in which the surfactant Pluronic P123 (10 g) was dissolved was added a mixture (20.5 g) of concentrated sulfuric acid: hydrochloric acid = 1: 3. Titanium isopropoxide (TIPO, 36 g) was added to the solution, followed by vigorous stirring for 10 hours. The formed gel was transferred to a Petri dish. The Petri dish was allowed to stand for 1 to 2 days in a humidity controlled oven (50-60%, 40 ° C) to allow the solvent to evaporate slowly, and the obtained dry powder was further dried by placing it in a 100 ° C drying oven for 12 hours See example 1). Since EISA this step, the channel is filled with an amorphous hexagonal P123 uom -TiO ₂ to give the _{(h - TiO 2 - uom)} ( Fig. 1e). The small angle X-ray (SAX) diffraction pattern of amorphous h- uom- TiO ₂ showed diffraction peaks at 2θ = 0.68 (d = 12.9 nm) (FIG. 2a), which supports the presence of mesopores. However, the wide angle X-ray (WAX) diffraction pattern exhibited uncharacterized broad peaks centered at 2? = ~ 26, ~ 48, and 60 (Figure 2b), indicating the formation of amorphous h- uom -TiO ₂ Is amorphous. Transmission electron microscopy (TEM) images (FIG. 2c, d) of amorphous uom -TiO ₂ show that the channels are structurally regular with a hexagonal system and the skeleton is amorphous.

The amorphous h- uom- TiO ₂ filled with the surfactant was calcined at 300 ° C for 1 hour under N ₂ flow to carbonize the P123 surfactant. After this carbonization step, white amorphous h- uom- TiO ₂ turned black due to the amorphous carbon (C) filling the channel walls. The SAX diffraction pattern of C-lined amorphous h- uom- TiO ₂ shows the presence of diffraction peaks at 2θ = 0.76 (d = 11.6 nm) (FIG. 2e), which indicates the presence of amorphous. The WAX diffraction pattern showed weak diffractions at 2? = 25.1, 37.5, 48.2, 54.5, and 63.0 ° with broad weak peaks at 2? =? 26. Since the diffractions at 2θ = 25.1, 37.5, 54.5 and 63.0 ° correspond to the (110), (401), (020), (113) and (313) planes of crystalline TiO ₂ -B, It can be concluded that a small fraction of the TiO ₂ wall in the amorphous h- uom -TiO ₂ filled with surfactant has already crystallized as TiO ₂ -B. The low magnification TEM image (Fig. 2g) of the C-packed amorphous h- uom- TiO ₂ -B shows a much more vivid contrast in the structured channels in the hexagonal system, 2h) show that the TiO ₂ wall is still amorphous. After firing the C-packed amorphous h- uom- TiO ₂ at 450 ° C. for 6 hours, the SAX diffraction pattern of the sample showed strong diffraction peaks at 2θ = 0.82 (d = 10.7 nm) Which is still well preserved (Fig. 2i). Interestingly, WAX diffraction pattern of the sample is to show typical diffraction line of crystalline TiO ₂ -B at 2θ = 14.2, 25.1, 28.5, 33.2, 37.5, 44.0, 48.2, 54.5, 57.5, 62.5, and 67.5 The crystalline TiO ₂ - (001) / (200), 110, 002, 310, 401, 003, 020, 113, 022, 313, (Fig. 2J). These results show that the final material is crystalline h- uom- TiO ₂ -B. A low magnification TEM image (FIG. 2K) shows a vivid contrast of structurally ordered channels to a six-chamber system, and a high magnification TEM image (FIGS. 2L and 9) shows that the framework is highly crystalline with a uniform thickness of 5 nm gave. As described above, the diffraction lines in FIG. 1J are considerably wider to match the thin skeleton, and the thickness of the skeleton estimated based on the (002) peak Scherrer equation was 5.6 nm. Electron diffraction of selected areas of the low magnification TEM image (FIG. 2k, inset) also results in electron diffraction from the (001) / (200), (110), (002), (310) Show.

Manufactured h- uom -TiO ₂ -B is not only has the structure of a regular uniform meso pores (long range ordering) as a long-range, TiO ₂ -B purity is very high. In fact, producing high purity TiO ₂ -B irrespective of the forms was not an easy task. Therefore, according to the results of analysis in the existing literature, about 70% of reported TiO ₂ -B is mixed with anatase. Processes that produce high purity TiO ₂ -B are very valuable. Indeed, the amount of sulfuric acid added in the initial gel in the process according to the present invention plays an important role in the successful synthesis of h- uom- TiO ₂ -B. For example, when sulfuric acid is used, or less than 50% of sulfuric acid rom - it is formed of anatase (rom -anatase) (Fig. 11). When using more than 50% sulfuric acid, only small amounts of anatase nanoparticles are produced.

The crystallization temperature also has a significant effect on the successful synthesis of h- uom- TiO ₂ -B. When crystallized at 400 ° C and at 500 ° C, rm-anatase is formed, and carbon-lined houm-TiO ₂ -B is formed at 400 ° C.

Surfactant is filled amorphous h - uom - a TiO _2, C- filled amorphous h - is the uom -TiO _2, and the final product crystalline h - uom -TiO ₂ -B adsorption - desorption isotherms are 3 (the left ). All isotherms represent Type IV N ₂ isotherms, which confirm the mesophase characteristics of the cylinder shape. The relatively steep capillary condensation steps in the P / P _o range between 0.57 and 0.75 show that the channel size is constant. In particular, for the final h - uom -TiO ₂ -B, the much sharper capillary edge step that occurs in the narrower P / P _o region shows that the channel size is highly uniform. In addition, the end h - typical type history H1 (hystersis) loop in uom -TiO ₂ -B show that a uniform cylindrical channels of a regular structure with long-range. The channel size varies from 3 to 7 nm (Fig. 3, right-hand diagram). Interestingly, surfactant - filled amorphous h - uom - TiO ₂ and C - line amorphous h - uom - TiO ₂ have two modes of channel systems with the largest channel sizes of 3.8 and 4.7 nm, h - uom - TiO ₂ - B has a channel system in one mode and the largest size is 5.4 nm. It is also interesting to note that these results show that when the amorphous TiO ₂ skeleton is converted to the crystalline TiO ₂ -B skeleton, the channel size increases as well as becomes uniform. Surface areas of amorphous h - uom - TiO ₂ filled with surfactant, C - line amorphous h - uom - TiO ₂ and crystalline h - uom - TiO ₂ - B are 291, 251 and 233 m ² g ^-1, respectively. Thus, the surface area of the final crystalline h - uom - TiO ₂ - B is large enough for a variety of applications.

In the case of semiconductor nanoparticles, the band gap energy (E _g ) decreases as the size increases. Since the crystalline TiO ₂ is a kind of semiconductor, its size-E _g relation should be in accordance with the relation of semiconductors. This relationship can also be used as a criterion for determining the size of the crystalline TiO ₂ . In addition, for the crystalline h - uom -anatase, the starting point of the electronic absorption spectrum (430 nm, 2.88 eV) was 30 nm (0.22 eV) compared to anatase nanoparticles ). ≪ / RTI > This phenomenon is caused by the crystalline interconnection between the constituent nanocrystals and leads to the formation of a three-dimensionally extended polycrystalline anatase. As a result, the skeleton thickness is only ~ 5 nm, but h - uom - anatase behaves like a very large polycrystalline anatase. Similarly, in the case of TiO ₂ -B, the starting point (470 nm, 2.64 eV) of the electron absorption spectrum of h - uom -TiO ₂ -B is 5-7 nm TiO ₂ -B nano (0.36 eV) as compared with the particles (413 nm, 3.00 eV) (Fig. 4). As a result, the starting point of the electron absorption spectrum of h - uom - TiO ₂ - B becomes similar to rutile. According to the elemental analysis of h - uom - TiO ₂ - B, there is neither nitrogen nor carbon and a negligible amount of sulfuric acid appears, which is due to the bathochromic shift of the absorption starting band and the resulting decrease in E _g . It does not originate from the insertion. This phenomenon will be helpful in photochemical applications of h - uom - TiO ₂ - B under sunlight or visible light.

(4-CP) decomposition and methylene blue (MB) decomposition when hydrogen is produced from methanolic water, h - uom- TiO ₂ -B, np -TiO ₂ -B, A comparison of the surface-corrected photochemical activities of P25 and anatase nanoparticles is shown in FIG. At this time, to compare the intrinsic photocatalytic activities of the materials, the surface-corrected activities were compared. The uom -TiO ₂ -B 2 times more significant than active np -TiO ₂ -B - 3 In both cases, decomposing molecules h - despite the fact that only go into the interior of the uom -TiO ₂ -B, h Respectively. These results demonstrate the advantage of the conversion of the crystalline interconnection of TiO ₂ -B nanoparticles to the three-dimensional polycrystalline TiO ₂ -B, and this conversion will also greatly assist in charge separation in photochemical applications.

In short, the present invention successfully synthesized h- uom- TiO ₂ -B with high purity and large scale (> 10 g) by combining EISA method and CASH method developed for uom -anatase synthesis. The addition of sulfuric acid played an important role in the successful synthesis of h- uom- TiO ₂ -B. Due to the formation of large polycrystalline TiO ₂ -B crystals with homogeneous mesoporous channels, the 5-nm thick crystalline TiO ₂ -B skeleton is extended to a highly extended three-dimensional framework, resulting in the formation of h - uom -TiO ₂ The E _g of -B is reduced by 0.36 eV compared to the nanoparticles. H - uom- TiO ₂ -B exhibits much higher performance during the production of hydrogen from methanolic water, during 4-chlorophenol (4-CP) decomposition and during photocatalytic application for methylene blue (MB) decomposition .

For the first time in the present invention, TiO ₂ -B crystals with structured regular mesopores such as hexagonal systems were provided, especially those with high purity and large scale (> 10 g). Further, according to the present invention, TiO ₂ -B crystal having a regular structure meso pore is, TiO ₂ -B nm was compared to a band gap energy is significantly reduced particles, better performance in the applied photocatalytic surface than TiO ₂ -B nanoparticles .

1 is a conceptual view of a possible four types of (ad) and 6 uniformly method of producing a structural regular meso pores as TiO ₂ -B political room for the TiO ₂ -B.
Figure 2 is a surface active agent is an amorphous filled h _{- uom - TiO 2 -B (ad} ), C- amorphous line _{h - uom -TiO 2 -B (eh} ), and the crystalline _{h - uom -TiO 2 -B (il} ) Of SAX and WAX diffraction patterns and low magnification and high magnification TEM images. The insert of panel k shows the FFT (Fast Fourier Transform) of the TEM image of k.
Figure 3 is a surfactant-filled amorphous _{h - uom - TiO 2 -B (} a, d), C- amorphous line _{h - uom -TiO 2 -B (b} , e), and the crystalline h - uom -TiO ₂ - (Ac) and pore size distribution (df) of adsorbed-desorbed B (c, f).
Figure 4 is an anatase, rutile, Cod Inc. P25, TiO ₂ -B nanoparticles (np -TiO ₂ -B), and h-uom- TiO a comparison of the diffuse reflectance UV-vis spectrum of ₂ -B (a : Corrected intensity, b: 380-470 nm).
5 is reduced during (a), 4-CP decomposition during (b) and MB decomposition during (c), anatase, Cod Inc. P25, np -TiO ₂ -B, and h- uom water-photocatalyst TiO ₂ -B Activity. (df) compares the corresponding initial reaction rates of the respective reactions.
Fig. 6 is a schematic diagram simply showing the present invention.
FIG. 7 is a TEM image showing the long-range structural regularity of the surfactant-filled hexagonal mesoporous material in the amorphous TiO ₂ obtained by EISA and the corresponding FFT (Fast Fourier Transform) image.
Figure 8 is a TEM image and corresponding FFT (Fast Fourier Transform) image showing the long-range structural regularity of the hexagonal mesopores in amorphous TiO ₂ with channel walls filled with amorphous carbon.
9 is an HR-TEM image of the h-uom -TiO ₂ -B showing crystalline TiO ₂ -B backbone at two different magnifications.
Figure 10 is an HR-TEM image of TiO ₂ -B nanoparticles (control) showing crystalline TiO ₂ -B skeleton at two different magnifications.
Fig. 11 is a WAX diffraction pattern of various TiO ₂ obtained from the process shown in Fig. 1, using a gel having a different H ₂ SO ₄ usage without changing other variables.
FIG. 12 is a schematic diagram showing a method of manufacturing a mesoporous TiO ₂ -B structurally regular in a hexagonal system by combining an EISA method and a CASH method.
Figure 13 shows the Raman spectrum (dotted line) of the h- uom -TiO ₂ -B in the Raman spectrum (solid line) and a pure crystalline TiO ₂ -B nanoparticles (np -TiO ₂ -B). This shows that the Raman bands are exactly the same.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for further illustrating the present invention, and the scope of the present invention is not limited by these examples.

<Material>

Titanium isoproxide [> 98%, Ti (OCH (CH ₃ ) ₂ ) ₄ , TIP] was purchased from Across. Anatase nanoparticles (<25 nm), Pluronic P123, methylene blue (MB), and 4-chlorophenol were purchased from Aldrich. P25 was purchased from Daegu. Reagents were used as received without further purification.

Example  One

As shown in Fig. 12, in a typical synthesis method, 10 g of Pluronic P123 was dissolved in 300 g of ethanol at room temperature. A mixture of concentrated H ₂ SO ₄ (5.5 g) and concentrated HCl (15 g) was added to the ethanol solution and stirred at 40 ° C for 3 hours. TIP (36 g) was added to the acidic ethanol solution and vigorously stirred for 10 hours. The mixed solution was transferred to a Petri dish and then allowed to stand at 40 [deg.] C for 24-48 hours in a humidity (50-60%) controlled chamber to evaporate the solvent. Then it dried further (the filled amorphous uom -TiO ₂ surface active agent), a petri dish, which receives the dried film at 100 ℃ for 12 hours and the product value. Surfactant-filled amorphous uom -TiO ₂ was calcined at 300 ° C for 1 hour under continuous N ₂ flow to carbonize the channel-filled surfactant. C-line amorphous uom -TiO ₂ was calcined at 450 ° C for 5 hours to form h - uom -TiO ₂ -B.

Known processes (Y. Ren, Z. Liu, F. Pourpoint, AR Armstrong, CP Grey, PG Bruce, Angew. Chem. Int. Ed. 2012, 51, 2164-2167. And M. Kobayashi, VV Petrykin, M TiO ₂ -B nanoparticles (5-7 nm, FIG. 10) were prepared according to Kakihana, K. Tomita and M. Yoshimura, Chem . Mater . 2007, 19 , 5373-5376.

[Photocatalyst activity measurement]

Air-tight continuous flow stainless steel reactor (YL-6000) connected with an on-line GC system equipped with a flame ionization detector (FID) and a pulsed discharge detector (PDD) reactor, hydrogen production experiments were carried out. Specifically, 0.1 g of the catalyst sample was placed in a vial containing 20 mL of water and 4 mL of methanol. The vial was placed in the reactor and Ar (99.9999%) was shed at various flow rates at 6 mL / min under dark conditions until the residual air in the reactor disappeared. Subsequently, a standard AM-1.5 solar simulator (HAL-302 Asahi) was irradiated at a power of 72 mW cm ^{- 2} to the sample under Ar continuous flow. The light intensity was controlled using a 1-sun checker (CS-20, Asahi Spectra Co., Ltd.). The light irradiation area was 6 cm ² . The generated hydrogen gas is Carboxen (Supelco) line pulse discharge detector of the column is attached (pulsed discharge detector, PDD) was measured by a generating amount per unit area (1 cm ²⁾ nanomolar (nmol), i.e. nmol cm ^-2 per h ^-1 . &lt; / RTI &gt;

Photocatalytic decomposition of methylene blue (MB) and 4-chlorophenol (4-CP) was performed using an oriel 200 W arc Hg lamp (Oriel CA-9015). Each catalyst (0.05 g) was placed in 50 mL (1 aliquot) of MB solution (10 ppm, mg / L). Before irradiation, the heterogeneous solution was equilibrated with the adsorption and desorption under agitation for 1 hour under dark conditions. The light absorption change of the methylene blue solution was monitored at 660 nm and the 4-chlorophenol was monitored at 225 nm.

Claims (14)

A TiO ₂ -B crystal characterized by having ordered mesoporous structure with six ordered crystal structures.
delete The TiO ₂ -B crystal according to claim 1, wherein the TiO ₂ -B is capable of intercalating cations.
Structure A TiO ₂ -B structure, wherein the framework is a TiO ₂ -B crystal form with regular six-electron system channels formed.
The TiO ₂ -B structure according to claim 4, characterized in that the hexagonal channel is filled with a surfactant or carbonized carbon.
The TiO ₂ -B structure according to claim 4, wherein the hexagonal channel is one in which the channel size is in one mode and the skeleton is crystalline.
delete CLAIMS What is claimed is: 1. A method of making a crystalline TiO ₂ -B structure having ordered ordered mesoporous structure with structured regular six-
A preparation of a precursor solution containing a Ti source, a mesopore-directing agent, an acid catalyst and a solvent;
As a step of evaporating the solvent from the precursor solution, the mesoporous-inducing agent and the hydrolyzed Ti source undergo self-assembly, whereby a structured regular mesopore is formed in the titanium oxide by the mesoporous-inducing agent, B in which the mesoporous-inducing agent forms a filled and agglomerated titanium oxide structure;
A step C for carbonizing the mesopore-inducing agent filled in the structured regular mesopores; And
(D) crystallizing the structure into TiO ₂ -B by firing while removing the carbonized aggregates filled in the regular mesopore,
Is to control the types and mixing ratio of the A phase of the acid catalyst characterized in that the structural regular meso pores created in the TiO ₂ -B, method for producing a TiO ₂ -B structure.
delete The method of claim 8, wherein the precursor solution in meso pore-inducing agent concentration range of from 0.01 mole to 1 mole to method for producing a TiO ₂ -B structure characteristics.
The method of claim 8, wherein the meso pore-inducing agent is a method for producing a TiO ₂ -B structure is characterized by a surface active agent.
A TiO ₂ -B crystal having an ordered mesoporous structure according to any one of claims 1 to 3 or a TiO ₂ -B crystal according to any one of claims 4 to 6, while the scaffold (framework) is an electroactive catalyst is characterized by containing a crystalline form of TiO ₂ -B structure.
A TiO ₂ -B crystal having an ordered mesoporous structure according to any one of claims 1 to 3 or a TiO ₂ -B crystal according to any one of claims 4 to 6, Wherein the framework comprises a crystalline TiO ₂ -B structure.
A TiO ₂ -B crystal having an ordered mesoporous structure according to any one of claims 1 to 3 or a TiO ₂ -B crystal according to any one of claims 4 to 6, while the scaffold (framework) is a process for producing hydrogen from water in the presence photocatalyst containing crystalline form of TiO ₂ -B structure.

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