阅读说明：本技术 一种简易的蓝/黑色二氧化钛光催化材料的制备方法 (Simple preparation method of blue/black titanium dioxide photocatalytic material ) 是由 潘新花 雷伟生 王凤志 叶志镇 于 2021-05-18 设计创作，主要内容包括：本发明公开了一种简易的蓝/黑色二氧化钛(TiO-(2-x))光催化材料的制备方法,蓝/黑色二氧化钛(TiO-(2-x))光催化材料由铝箔在较高温度下还原商用二氧化钛纳米晶颗粒(P25)制备得到。其主要步骤为：将一定量的商用二氧化钛纳米晶颗粒用铝箔包裹,并使用压片机将该装有二氧化钛的铝箔压片,最后将其放置于管式炉中,通气体较高温度热处理一定时间,得到TiO-(2-x)产物。相较于传统的TiO-(2-x)制备方法,此方法具有操作简便、过程安全、可高通量制备等优势,得到的产物在模拟太阳光照射下,其光催化解水产氢性能相比商用二氧化钛纳米晶颗粒提升明显,为二氧化钛光催化生产氢气的产业化应用奠定了基础。(The invention discloses simple blue/black titanium dioxide (TiO) 2‑x ) Process for preparing photocatalytic material, blue/black titanium dioxide (TiO) 2‑x ) The photocatalytic material is prepared by reducing commercial titanium dioxide nanocrystalline particles (P25) by aluminum foil at higher temperature. The method mainly comprises the following steps: using a certain amount of commercial titanium dioxide nanocrystalline particlesWrapping with aluminum foil, tabletting with tablet press, placing in tube furnace, and heat treating at high temperature for a certain time to obtain TiO 2‑x And (3) obtaining the product. Compared with the conventional TiO 2‑x The preparation method has the advantages of simple and convenient operation, safe process, high-throughput preparation and the like, and the obtained product has obviously improved photocatalytic hydrolysis hydrogen production performance compared with commercial titanium dioxide nanocrystalline particles under the irradiation of simulated sunlight, thereby laying a foundation for the industrial application of titanium dioxide photocatalytic hydrogen production.)

1. A simple preparation method of a blue/black titanium dioxide photocatalytic material is provided, wherein the photocatalytic material is TiO_2-xThe method is characterized in that raw materials of the method are commercial titanium dioxide nanocrystalline particles P25 and commercial aluminum foil paper; in the preparation process, argon is used as protective atmosphere, and the method specifically comprises the following steps:

1) weighing commercial titanium dioxide nanocrystalline particles P25, wrapping the particles with cut aluminum foil paper, and folding and sealing the particles;

2) pressing the aluminum foil coated with P25 into sheets by a tablet press, putting the sheets into a corundum crucible, and putting the corundum crucible into a tubular furnace;

3) introducing argon, and carrying out heat treatment at 550-620 ℃ for 8-12 hours to prepare the blue/black titanium dioxide photocatalytic material TiO_2-x。

2. The method for preparing a blue/black titanium dioxide photocatalytic material according to claim 1, wherein in the step 1), the mass ratio of aluminum foil to commercial titanium dioxide nanocrystalline particles is 1: 1.

3. the method for preparing a blue/black titanium dioxide photocatalytic material according to claim 1, wherein the step 2) is specifically:

and (2) tabletting the aluminum foil coated with the commercial titanium dioxide nanocrystalline particles prepared in the step (1) by using a tablet machine, so that the commercial titanium dioxide nanocrystalline particles are uniformly distributed in the aluminum foil and are in close contact with the upper layer and the lower layer of the aluminum foil, the obtained aluminum foil has no obvious wrinkles, then supporting the aluminum foil by using a corundum crucible, and placing the aluminum foil in a tubular furnace.

4. The method for preparing a blue/black titanium dioxide photocatalytic material according to claim 1, wherein the step 3) is specifically:

introducing high-purity argon gas of 60-120 standard ml/min into a tube furnace, controlling the pressure of the argon gas to be 0.15MPa by using a pressure reducing valve, introducing the argon gas for a period of time before starting heating, then increasing the temperature in the tube furnace to 550-620 ℃ at a certain heating rate, preserving the heat for 8-12h at the temperature, stopping introducing the gas after naturally cooling to the room temperature, opening the tube furnace to take out an aluminum foil, opening the aluminum foil paper to collect the prepared blue/black titanium dioxide TiO, and collecting the prepared blue/black titanium dioxide TiO_2-xA photocatalytic material.

5. The method for preparing a titanium dioxide photocatalyst material having a blue/black color as defined in claim 4, wherein the period of time for introducing argon gas before the temperature rise is started is 40 to 60 minutes.

6. The method for preparing a blue/black titanium dioxide photocatalytic material according to claim 4, wherein the temperature increase rate is 2-3 ℃/min.

7. The method for preparing a blue/black titanium dioxide photocatalytic material according to any one of claims 1 to 6, wherein the heat treatment temperature is 600 ℃ or more and the heat treatment time is 10 hours or more, and the product obtained is a black titanium dioxide photocatalytic material TiO_2-x。

8. A blue/black titanium dioxide photocatalytic material, characterized by being obtained by the method of any one of claims 1 to 6, and being used in the field of photocatalysis.

Technical Field

The invention relates to the field of photocatalytic materials, in particular to a simple blue/black titanium dioxide photocatalytic material (TiO)_2-xX is more than 0 and less than 2, namely oxygen-containing defects), and the material can be used for preparing hydrogen by decomposing water through photocatalysis.

Background

With the continuous progress of science and technology and the continuous improvement of the social production and living standard, the demand of people on clean and renewable energy sources is continuously improved. Among them, how to utilize light energy more efficiently is a clean energy which is inexhaustible and has a wide distribution, and has received a high attention from scientific and technological workers in various countries. At present, the development and utilization of solar energy in the world mainly comprise four ways of light-heat energy conversion, light-electric energy conversion, light-chemical energy conversion, light-biomass energy conversion and the like. Among them, the photocatalytic technology is an important method for photo-chemical energy conversion, and is regarded by the scientific community as being capable of directly utilizing light energy to convert abundant water resources into chemical energy such as hydrogen energy. Many researchers make important contributions in exploring photocatalytic micro-mechanisms, developing high-efficiency photocatalytic materials and the like, and photocatalytic technologies are gradually moving from laboratories to industries.

Titanium dioxide is the most studied photocatalytic material at present, and is regarded as the photocatalytic material with the best commercial potential due to the advantages of high photocatalytic activity, excellent photocatalytic stability, simple production, low cost and the like. At present, anatase crystal and rutile crystal with the average grain diameter of 25 nanometers are mixed according to the mass ratio of 79: 21, has been successfully used commercially as a material for photocatalytic contaminant degradation. However, the forbidden band width reaches 3.2eV, the light absorption band edge is about 400nm, and only ultraviolet light with energy of about 4% in sunlight can be utilized, so that the efficiency of hydrogen production by water photolysis is extremely low, and the large-scale use of the material is hindered. Therefore, how to improve the visible light catalytic efficiency of the titanium dioxide is a problem which is long-term addressed by the scientific community.

It was found in the study that TiO with abundant oxygen vacancies_2-xBecause of its structural, chemical, electronic and optical properties compared with TiO₂The light absorption range of the titanium dioxide is shifted to an infrared light region by obvious change, blue/black is presented, the sunlight absorption efficiency of the titanium dioxide is greatly improved, and the photocatalytic activity under sunlight is remarkably improved. At present, blue/black titanium dioxide (TiO) is mainly prepared by methods such as hydrogen or hydrogen plasma reduction, high-temperature chemical reduction, electrochemical reduction and the like_2-x). The invention aims to prepare blue/black titanium dioxide (TiO) with high photocatalytic activity at mild atmosphere and lower temperature by using a simple, efficient and safe commercial aluminum foil reduction method_2-x) The method is based on the existing commercial raw materials and a simple method, can greatly improve the safety of the preparation process, reduces the production cost, and is beneficial to popularization and use.

Disclosure of Invention

The invention uses commercial aluminum foil paper as raw material for the first time, and prepares blue/black titanium dioxide (TiO) mildly in inert atmosphere_2-x) The preparation method is simple in preparation process, safe and mild in preparation process, low in cost, rich in raw material source and high in activity. The specific steps can be as follows:

1) weighing commercial titanium dioxide nanocrystalline particles P25, wrapping the particles with cut aluminum foil paper, and folding and sealing the particles; wherein, the mass ratio of the aluminum foil to the commercial titanium dioxide nanocrystalline particles is preferably 1: 1;

2) pressing the aluminum foil coated with P25 into sheets by a tablet press, putting the sheets into a corundum crucible, and putting the corundum crucible into a tubular furnace; the following requirements are met during tabletting: tabletting the aluminum foil coated with the commercial titanium dioxide nanocrystalline particles (P25) prepared in the step 1) by using a tablet machine to ensure that the commercial titanium dioxide nanocrystalline particles (P25) are uniformly distributed in the aluminum foil and are in close contact with the upper layer and the lower layer of the aluminum foil, the obtained aluminum foil has no obvious wrinkles, then supporting the aluminum foil by using a corundum crucible, and placing the aluminum foil in a tube furnace.

3) Introducing argon, and carrying out heat treatment at 550-620 ℃ for 8-12 hours to prepare the blue/black titanium dioxide photocatalytic material TiO_2-xThe method specifically comprises the following steps:

introducing high-purity argon gas of 60-120 standard ml/min (60-120 sccm) into the tube furnace, controlling the argon pressure to be 0.15MPa by using a pressure reducing valve, introducing the argon gas for a period of time before starting to heat up, then raising the temperature in the tube furnace to 550-620 ℃ at a certain heating rate, preserving the temperature for 8-12h, naturally cooling to room temperature, stopping introducing the gas after finishing the heat treatment process, opening the tube furnace to take out an aluminum foil, opening the aluminum foil to collect the prepared blue/black titanium dioxide (TiO) by opening the aluminum foil_2-x) A photocatalytic material.

Wherein the time period for introducing argon before starting temperature rise is usually 40-60 min.

The rate of temperature rise is preferably 2 to 3 ℃/min.

Blue/black titanium dioxide (TiO) of the invention_2-x) It is a photocatalytic material with high activity. The forming mechanism is as follows: in an inert gas argon atmosphere, gaseous oxygen is lacked, and the aluminum foil can extract oxygen from titanium dioxide nanocrystalline particles (P25) due to higher chemical activity at higher temperature, so that oxygen vacancies are generated in P25, the structural, chemical, electronic and optical properties of the aluminum foil are remarkably changed, and blue/black titanium dioxide (TiO) is generated_2-x) The light absorption range is shifted to an infrared light region, so that the sunlight absorption efficiency is greatly improved, and the photocatalytic hydrolysis hydrogen production activity is higher. In particular, by controlling the heat treatment temperature to be more than 600 ℃ and the heat treatment time to be more than 10 hours in the method of the present invention, black titanium dioxide having excellent hydrogen production performance by photocatalytic hydrolysis under sunlight can be directly obtained.

The invention has the beneficial effects that:

1) the blue/black titanium dioxide (TiO) prepared by the invention_2-x) The catalyst has excellent performance of producing hydrogen by decomposing water under photocatalysis under ultraviolet light and simulated sunlight. After the Pt cocatalyst is loaded, the hydrogen production rate of the decomposed water reaches 14.25 mmoleg under the irradiation of 365nm ultraviolet light^-1h^-1The hydrogen production rate of water decomposition reaches 317.6 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1Which are respectively 1.87 times and 12.45 times of P25 under the same conditions.

2) The blue/black titanium dioxide (TiO) prepared by the invention_2-x) The shape of the material is not changed obviously, the material is still nano-particles with the particle size of about 25nm, and the anatase and rutile mixed phase of the material is maintained. Compared with other reduction preparation methods, the photocatalytic activity of the material is kept to the maximum extent.

3) The raw materials used in the present invention are all from materials that have been commercialized on a large scale. The used raw materials are fewer in types, only three types of raw materials are P25, aluminum foil and argon, and interference caused by introduction of other raw materials to the preparation process is avoided. If other metals are introduced or the titanium dioxide is in an air atmosphere, other raw materials may participate in the reaction, so that the formation mechanism of the black titanium dioxide is unclear, the black titanium dioxide is easily interfered by other reactions, and the quality of the product is unstable. The aluminum foil paper filled with P25 is tabletted in the early stage of preparation, which is beneficial to the close contact between P25 and aluminum foil, can obviously improve the efficiency of reducing P25 by the aluminum foil, and obtain high-quality blue/black titanium dioxide (TiO)_2-x). If the wrapping is not tight enough or the crucible is simply covered with aluminum foil, the product quality will be affected.

4) The preparation method disclosed by the invention is a semi-contact method, the reducing agent and the titanium dioxide are in close contact, but the reducing agent is removed by subsequent separation without acid washing and other methods, the use of dangerous reagents can be avoided in the whole process, the operation is simple, the process is safe, the reaction is mild, the cost is low, the yield is high, and the industrial prospect is high.

Drawings

FIG. 1 is an appearance of a sheet-pressed aluminum foil wrapped with a sheet and a black titanium dioxide (TiO) sheet_2-x) Powder and P25 appearance comparison figure.

FIG. 2 is a black titanium dioxide (TiO)_2-x) Of granulesScanning Electron Microscope (SEM) images, the left and right images are at different magnifications.

FIG. 3 is a black titanium dioxide (TiO)_2-x) XRD pattern of the particles.

FIG. 4 is blue/black titanium dioxide (TiO)_2-x) Absorption spectrum of the powder.

FIG. 5 is blue/black titanium dioxide (TiO)_2-x) The hydrogen change with time of decomposing water under 365nm illumination (left) and the hydrogen production rate comparison chart (right).

FIG. 6 is blue/black titanium dioxide (TiO)_2-x) The time-dependent hydrogen production map (left) and the hydrogen production rate comparison map (right) of the decomposed water under AM1.5G irradiation.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

Example 1

The commercial aluminum foil paper is cut to be 10cm multiplied by 10cm in size, and is folded in half, folded and the like to obtain an aluminum foil bag of about 5cm multiplied by 8 cm. Then, 0.5g of the weighed commercial titanium dioxide nanocrystal particles (P25) were put into an aluminum foil bag, the bag mouth was closed, and the bag was folded in half into an aluminum foil sheet of 4 cm. times.4 cm. And tabletting the aluminum foil coated with the P25 by using a tabletting machine to ensure that the P25 is uniformly distributed in the aluminum foil and is tightly contacted with the upper layer and the lower layer of the aluminum foil. Then, a corundum crucible is used for supporting the aluminum foil, the aluminum foil is placed in a tube furnace, high-purity argon gas of 60 standard milliliters per minute (60sccm) is introduced, and the pressure of the argon gas is controlled to be 0.15MPa by a pressure reducing valve. Introducing argon for 60min before heating to remove air in the quartz tube, heating the tube furnace to 600 deg.C at a heating rate of 3 deg.C/min, maintaining the temperature for 12 hr, naturally cooling to room temperature, stopping introducing air, opening the tube furnace, taking out aluminum foil, and collecting black product to obtain black titanium dioxide (TiO)_2-x) A photocatalytic material.

Black titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 14.25 mmoleg^-1h^-1The hydrogen production rate of water decomposition reaches 317.6 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1. In this method, the heat treatment temperature isThe heat treatment time is 12 hours at 600 ℃, and black titanium dioxide (TiO) with excellent photocatalytic performance can be directly obtained_2-x)。

Example 2

The commercial aluminum foil paper is cut to be 10cm multiplied by 10cm in size, and is folded in half, folded and the like to obtain an aluminum foil bag of about 5cm multiplied by 8 cm. Then, 0.5g of the weighed commercial titanium dioxide nanocrystal particles (P25) were put into an aluminum foil bag, the bag mouth was closed, and the bag was folded in half into an aluminum foil sheet of 4 cm. times.4 cm. And tabletting the aluminum foil coated with the P25 by using a tabletting machine to ensure that the P25 is uniformly distributed in the aluminum foil and is tightly contacted with the upper layer and the lower layer of the aluminum foil. Then, a corundum crucible is used for supporting the aluminum foil, the aluminum foil is placed in a tube furnace, high-purity argon gas of 60 standard milliliters per minute (60sccm) is introduced, and the pressure of the argon gas is controlled to be 0.15MPa by a pressure reducing valve. Introducing argon for 60mins before starting to heat up to remove air in the quartz tube, heating the tube furnace to 620 ℃ at the heating rate of 3 ℃/min, keeping the temperature for 6h, naturally cooling to room temperature, stopping introducing air, opening the tube furnace to take out an aluminum foil, opening the tube furnace to collect a dark blue product to obtain the dark blue titanium dioxide (TiO)_2-x) A photocatalytic material.

The dark blue titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 11.85 mmoleg^-1h^-1The hydrogen production rate of water decomposition reaches 229.3 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1. In this example, the heat treatment temperature reached 620 ℃, but since the heat treatment time was about 6 hours, less than 12 hours, the product obtained was dark blue titanium dioxide.

Example 3

The commercial aluminum foil paper is cut to be 10cm multiplied by 10cm in size, and is folded in half, folded and the like to obtain an aluminum foil bag of about 5cm multiplied by 8 cm. Then, 0.5g of the weighed commercial titanium dioxide nanocrystal particles (P25) were put into an aluminum foil bag, the bag mouth was closed, and the bag was folded in half into an aluminum foil sheet of 4 cm. times.4 cm. And tabletting the aluminum foil coated with the P25 by using a tabletting machine to ensure that the P25 is uniformly distributed in the aluminum foil and is tightly contacted with the upper layer and the lower layer of the aluminum foil. Then, the aluminum foil is supported by a corundum crucible, and the aluminum foil is placed in a tube furnace, and high-purity argon of 90 standard milliliters per minute (90sccm) is introducedAnd controlling the argon pressure to be 0.2MPa by using a pressure reducing valve. Introducing argon for 40mins before starting to heat up to remove air in the quartz tube, heating the tube furnace to 600 ℃ at the heating rate of 3 ℃/min, preserving the heat for 8h at the temperature, naturally cooling to room temperature, stopping introducing the air, opening the tube furnace to take out an aluminum foil, opening the tube furnace to collect a blue-black product to obtain blue-black titanium dioxide (TiO)_2-x) A photocatalytic material.

The bluish black titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 14.12 mmoleg^-1h^-1The hydrogen production rate of water decomposition reaches 166.3 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1. In this example, the heat treatment temperature was 600 ℃ but the heat treatment time was 8 hours, less than 10 hours, and the obtained product was blue-black titanium dioxide.

Example 4:

the commercial aluminum foil paper is cut to be 10cm multiplied by 10cm in size, and is folded in half, folded and the like to obtain an aluminum foil bag of about 5cm multiplied by 8 cm. Then, 0.5g of the weighed commercial titanium dioxide nanocrystal particles (P25) were put into an aluminum foil bag, the bag mouth was closed, and the bag was folded in half into an aluminum foil sheet of 4 cm. times.4 cm. And tabletting the aluminum foil coated with the P25 by using a tabletting machine to ensure that the P25 is uniformly distributed in the aluminum foil and is tightly contacted with the upper layer and the lower layer of the aluminum foil. Then, a corundum crucible is used for supporting the aluminum foil, the aluminum foil is placed in a tubular furnace, high-purity argon of 90 standard milliliters per minute (90sccm) is introduced, and the pressure of the argon is controlled to be 0.1MPa by a pressure reducing valve. Introducing argon for 30mins before starting to heat up to remove air in the quartz tube, heating the tube furnace to 600 ℃ at the heating rate of 3 ℃/min, preserving the heat for 6h, naturally cooling to room temperature, stopping introducing air, opening the tube furnace to take out an aluminum foil, opening the tube furnace to collect a blue product to obtain blue titanium dioxide (TiO)_2-x) A photocatalytic material.

Blue titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 8.52 mmoleg^-1h^-1The hydrogen production rate of water decomposition reaches 163.2 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1. In this example, the heat treatment temperature was 600 ℃ but the heat treatment time was 6 hours, less than 10 hours, and the obtained product was blue titanium dioxide.

Example 5:

the commercial aluminum foil paper is cut to be 10cm multiplied by 10cm in size, and is folded in half, folded and the like to obtain an aluminum foil bag of about 5cm multiplied by 8 cm. Then, 0.5g of the weighed commercial titanium dioxide nanocrystal particles (P25) were put into an aluminum foil bag, the bag mouth was closed, and the bag was folded in half into an aluminum foil sheet of 4 cm. times.4 cm. And tabletting the aluminum foil coated with the P25 by using a tabletting machine to ensure that the P25 is uniformly distributed in the aluminum foil and is tightly contacted with the upper layer and the lower layer of the aluminum foil. Then, a corundum crucible is used for supporting the aluminum foil, the aluminum foil is placed in a tube furnace, high-purity argon gas of 60 standard milliliters per minute (60sccm) is introduced, and the pressure of the argon gas is controlled to be 0.15MPa by a pressure reducing valve. Introducing argon for 60mins before starting to heat up to remove air in the quartz tube, heating the tube furnace to 580 ℃ at the heating rate of 3 ℃/min, preserving the heat for 12h at the temperature, naturally cooling to room temperature, stopping introducing the air, opening the tube furnace to take out an aluminum foil, opening the tube furnace to collect a light blue product to obtain light blue titanium dioxide (TiO)_2-x) A photocatalytic material.

Light blue titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 7.13 mmoleg^-1h^-1The hydrogen production rate of water decomposition reaches 108.4 mu molg under the irradiation of simulated sunlight (AM1.5G)^-1h^-1. In this example, the heat treatment time was 12 hours, but the heat treatment temperature was 580 ℃ C, which was less than 600 ℃ C, and the product obtained was pale blue titanium dioxide.

Example 6:

weighed 0.5g of commercial titanium dioxide nanocrystalline particles (P25) were spread in a corundum crucible, cut out of aluminum foil paper to cover the crucible and sealed. The crucible was then placed in a tube furnace and high purity argon was introduced at 90 standard milliliters per minute (90sccm) and the argon pressure was controlled to 0.1MPa with a pressure reducing valve. Introducing argon for 30mins before the temperature rise is started to remove air in the quartz tube, raising the temperature in the tube furnace to 620 ℃ at the temperature rise rate of 3 ℃/min, preserving the heat for 8h at the temperature, and naturally coolingStopping ventilation after the heat treatment process is finished at room temperature, opening the tube furnace, taking out the crucible, opening the aluminum foil paper, and collecting the product to obtain gray titanium dioxide (TiO)_2-x) A photocatalytic material.

Gray titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 8.42 mmoleg^-1h^-1The hydrogen decomposition rate of water under the irradiation of simulated sunlight (AM1.5G) is 46.38 mu molg^-1h^-1. In this example, the aluminum foil covered the crucible without directly wrapping the titanium dioxide, and the resulting product was gray in color, with poorer photocatalytic performance than black and blue titanium dioxide.

Example 7:

0.5g of commercial titanium dioxide nanocrystalline particles (P25) and 0.5g of aluminum powder are mixed uniformly, spread in a corundum crucible, cut into aluminum foil paper to cover the crucible and sealed. The crucible was then placed in a tube furnace and high purity argon was introduced at 90 standard milliliters per minute (90sccm) and the argon pressure was controlled to 0.1MPa with a pressure reducing valve. Introducing argon for 30mins before starting to heat up to remove air in the quartz tube, heating the tube furnace to 620 ℃ at the heating rate of 3 ℃/min, keeping the temperature for 8h, naturally cooling to room temperature, stopping introducing air, opening the tube furnace, taking out a crucible, opening aluminum foil paper, collecting a product, and obtaining dark gray titanium dioxide (TiO)_2-x) A photocatalytic material.

The dark grey titanium dioxide (TiO) produced in this example_2-x) Under the irradiation of 365nm ultraviolet light, the hydrogen production rate of the water decomposed by the ultraviolet light reaches 11.35 mmoleg^-1h^-1The hydrogen decomposition rate of water under the irradiation of simulated sunlight (AM1.5G) is 198.78 mu molg^-1h^-1. In this case, the aluminum powder was completely mixed with titanium dioxide, and the titanium dioxide was directly wrapped without using aluminum foil, and the obtained product was dark gray in color, and had a poorer photocatalytic performance than black titanium dioxide.

And (3) performance testing:

1) and (4) SEM test: and observing the sample prepared in each embodiment under a scanning electron microscope to show that the sample is in a nanoparticle shape. For example, drawingsAnd 2 is a scanning electron microscope image of the micro-topography of the sample prepared in the example 1. As can be seen from the figure, the blue/black titanium dioxide (TiO) of the present invention_2-x) The material is particles with the particle size of about 25nm, the particles are irregularly and loosely arranged, and the material has no obvious change compared with a raw material P25. The nano-scale particle size is beneficial to improving the specific surface area, increasing the contact area of the photocatalytic material and water, being beneficial to the adsorption of water molecules, simultaneously being capable of obtaining more active sites and being beneficial to improving the efficiency of photolysis of water hydrogen.

2) XRD test: the sample obtained in each example was subjected to XRD measurement to obtain phase information of the material. For example, FIG. 3 is an X-ray diffraction pattern of the sample prepared in example 1. From the figure, blue/black titanium dioxide (TiO) can be seen_2-x) The diffraction peak of the compound is basically consistent with the characteristic peak of P25 of the raw material, and is anatase and rutile mixed crystal phase, but the diffraction peak intensity of the rutile phase is obviously enhanced relative to that of the anatase phase, which is attributed to blue/black titanium dioxide (TiO)_2-x) Some anatase phase in the sample was transformed into rutile phase.

3) And (3) testing diffuse reflection absorption spectrum: the diffuse reflection absorption spectrum of the sample prepared in each example is tested, and the sample is found to have obvious absorption to light of different wave bands. For example, FIG. 4 is a diffuse reflectance absorption spectrum test of the sample prepared in example 1. In contrast to P25, it can be seen that the absorption band edge for P25 is around 400nm, while blue/black titanium dioxide (TiO) is_2-x) The sample has better absorption in ultraviolet and visible light wave bands. The excellent light absorption performance is beneficial to the efficient utilization of sunlight, and the effect of improving the light energy-hydrogen energy conversion efficiency is achieved.

4) Testing the hydrogen performance of the photocatalytic decomposition water: the materials prepared in the above embodiments are respectively subjected to photocatalytic water decomposition hydrogen production performance tests, and fig. 5 is a graph of the change of hydrogen production with time and a comparison graph of hydrogen production rate of the samples prepared in the embodiments 1, 2, 3 and 4 under the irradiation of 365nm ultraviolet light and under the condition that 2% Pt is added in a photoreduction way as a promoter, so that the performance of the prepared samples is remarkably improved compared with that of P25; FIG. 6 shows the samples obtained in examples 1, 2, 3 and 4 irradiated with simulated sunlight (AM1.5G)In the figure, the hydrogen production quantity changes with time under the condition that the photo-reduction catalyst is added with 2% Pt as the promoter, and the comparison figure of the hydrogen production rate shows that the performance of the prepared sample is improved to a greater extent compared with that of P25. The above results show that blue/black titanium dioxide (TiO) is obtained_2-x) The sample has excellent photocatalytic performance.