Metal-doped p-type nanobismuth titanate, preparation and application thereof
The preparation of metal-doped p-type nano-bismuth titanate by solid-phase mixing method solves the problems of cumbersome methods and low reproducibility in the existing technology, realizes simple and controllable industrial production, and improves catalytic activity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-02
- Publication Date
- 2026-03-24
AI Technical Summary
Existing methods for metal doping of bismuth titanate are cumbersome and have low reproducibility, making it difficult to achieve efficient industrial production.
Using a solid-phase mixing method, a metal doping strategy with low valence and atomic radius smaller than Bi was employed. TiO2, Bi2O3 and the doped metal precursor were calcined at high temperature in a muffle furnace to form metal-doped p-type nano-bismuth titanate.
The preparation method is simple, controllable, reproducible, and low-cost, making it suitable for industrial production. Furthermore, the doping with metals forms new catalytic active sites, improving the efficiency of processes such as photocatalytic water splitting for hydrogen production.
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Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of nanocatalytic material preparation, and particularly relates to a metal-doped p-type nanobismuth titanate and a preparation method thereof. BACKGROUND
[0002] As a new material in perovskite materials, bismuth titanate is currently widely applied, including ferroelectric field effect transistors, photoelectric / piezoelectric conversion elements, thermoelectric materials, high-temperature piezoelectric ceramics and the like. The n-type semiconductor constructed by high-valence metal doping or the p-type semiconductor constructed by low-valence metal doping can further enhance the levels of photoelectric / piezoelectric conversion and conductivity.
[0003] Current methods for metal-doped bismuth titanate include high-frequency sputtering, radio frequency magnetron sputtering, sol-gel spin coating and solid-phase mixing. The first three processes are complicated and have low reproducibility, and are difficult to be industrialized and efficiently produced. Relatively speaking, the solid-phase mixing method is a simple strategy. Currently, an acrylic copolymer emulsion (Xianlin Dong et al., doi: 10.1016 / j.jeurceramsoc.2018.08.025) or a polyvinyl alcohol emulsion (Shujun Zhang et al., doi: 10.1016 / j.jeurceramsoc.2018.12.061) is usually used as a binder. The preparation process needs calcination, granulation, tabletting, high-temperature decomposition of the binder, and secondary ball milling, which is relatively complicated.
[0004] Therefore, it is urgent to develop a simple and efficient, reproducible and suitable for industrialized and efficient production method of metal-doped p-type nanobismuth titanate. SUMMARY
[0005] The application aims to provide a metal-doped p-type nanobismuth titanate and a preparation method thereof, which have the advantages of simplicity, controllability, good reproducibility, low cost and suitability for industrialized and efficient production.
[0006] A preparation method of a metal-doped p-type nanobismuth titanate, the method comprising:
[0007] (1) placing TiO2, Bi2O3 and a precursor of a doping metal into a ball mill jar, adding a liquid grinding medium, and fully wet-milling and mixing;
[0008] (2) vacuum drying the slurry after ball milling to remove the liquid, collecting the obtained powder sample and grinding the powder sample into a powder sample with a mortar;
[0009] (3) placing the powder sample in a crucible, high-temperature calcining in an air atmosphere muffle furnace, and obtaining the metal-doped p-type nanobismuth titanate after cooling.
[0010] Preferably, in step (1), the TiO2 is in anatase phase and / or rutile phase; the molar ratio of TiO2 to Bi2O3 is 3:1 to 1:20, preferably 3:1 to 3:2; the precursor of the doped metal is one or more of doped metal carbonate, doped metal bicarbonate, and doped metal acetate; the doped metal is one or more of Sr, Ba, Ca, Y, Zn, Cd, Co, Ni, Pb, and other metals with atomic radius less than Bi and valence of 2 and / or 1; the molar amount of the doped metal is 0.1 to 10.0% of bismuth titanate, preferably 0.1 to 5.0%; the liquid grinding medium is one or more of water, methanol, and ethanol; the volume ratio of the solvent to the mass of the ball-milled material (the sum of TiO2, Bi2O3, and the precursor of the doped metal) is 0.5 to 3.0 mL / g, preferably 1.0 to 2.0 mL / g; the ball-milling rotation speed is 200 to 800 rpm / min, preferably 300 to 600 rpm / min; the ball-milling time is 12 to 72 h, preferably 36 to 48 h; and the ball-milling material is one or more of hard materials such as agate and zirconia.
[0011] Preferably, in step (2), the drying temperature is 60 to 100°C, preferably 60 to 80°C; and the drying time is 12 to 36 h, preferably 18 to 24 h.
[0012] Preferably, in step (3), the material of the crucible is alumina and / or quartz; the muffle furnace calcination temperature is 400 to 1100°C, preferably 600 to 800°C; the calcination time is 1 to 12 h, preferably 2 to 6 h; and the temperature rising rate from room temperature to the calcination temperature is 2 to 10°C / min, preferably 5 to 10°C / min.
[0013] The preparation principle of the metal-doped p-type nano bismuth titanate provided by the present application is as follows: after TiO2, Bi2O3, and the precursor of the doped metal are thoroughly mixed, they are gradually melted and the precursor of the doped metal is decomposed in the muffle furnace during the temperature rising process; when the temperature is higher than 650°C, a new phase Bi4Ti3O12 is formed, in which low-valence metals partially replace Bi, and since the atomic radius of the low-valence metals is smaller than that of Bi and the valence of the low-valence metals is lower than that of Bi, Lewis acid sites with partial electron deficiency are formed, accompanied by the generation of a small amount of oxygen vacancies. 12 3+ 2+ 2+ , which induces the rapid migration of photo-generated electrons to the surface in the photocatalytic reaction, i.e., a typical p-type semiconductor.
[0014] Compared with the prior art, the present application has the following unique advantages:
[0015] (1) The present application constructs metal-doped p-type nanometer bismuth titanate by solid-phase mixing method, using metal doping strategy of low valence and atomic radius less than Bi; the doped metal and its surrounding environment form new catalytic active sites.
[0016] (2) The metal-doped p-type nanometer bismuth titanate described in the present application is a heterogeneous catalytic material, which can be applied to processes such as water splitting to produce hydrogen, and can be recycled and reused.
[0017] (3) The preparation method of the metal-doped p-type nanometer bismuth titanate described in the present application is simple and controllable, has good reproducibility, low cost, and is suitable for industrial high-efficiency production. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 XRD pattern of 2.0 mol% Ba-doped p-type nanometer bismuth titanate obtained in Example 1. DETAILED DESCRIPTION
[0019] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer and more understandable, the following embodiments will be further described in detail. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the scope of the present application. The experimental procedures not specified in the following examples are usually carried out under conventional conditions or under the conditions recommended by the manufacturer.
[0020] Example 1
[0021] 2.0 mol% Ba-doped p-type nanometer bismuth titanate was obtained by the following process: first, 6 mmol of TiO2(anatase phase), 4 mmol of Bi2O3 and 2.0 mol% of barium carbonate relative to the molar amount of Bi were put into a agate ball mill jar, 3 mL of water was added, after sealing with a cover, the rotation speed was 400 rpm / min, and the mixture was fully wet-milled for 48 h. Then the ball-milled slurry was dried at 80°C under vacuum for 24 h to remove the liquid, and the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was spread on an alumina crucible, and calcined in a muffle furnace at 750°C in air atmosphere for 2 h (the heating rate from room temperature to calcination temperature was 5°C / min). After cooling to room temperature, simple grinding obtained 2.0 mol% Ba-doped p-type nanometer bismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, labeled as Ba 2.0 -Bi4Ti3O 12 .
[0022] The XRD test results show that the main crystal phase of the prepared Ba-doped p-type nanometer bismuth titanate is Bi4Ti3O 12 (a recognized p-type semiconductor, reference: doi:
[0023] 10.1002 / adfm.201303214, same below), the doping of Ba forms a small amount of new crystal phase BaBi4Ti4O 15 .
[0024] The reaction evaluation is shown in Application Example 1 and Comparative Example 1.
[0025] Example 2
[0026] 1.0 mol% Sr-doped p-type nano-bismuth titanate was obtained by the following process: first, 6 mmol of TiO2(rutile phase), 4 mmol of Bi2O3and 1.0 mol% of strontium acetate relative to the molar amount of Bi were put into a zirconium oxide ball mill jar, 3 mL of water was added, after sealing with a cover, the rotation speed was 400 rpm / min, and the mixture was fully wet-milled for 48 h. Subsequently, the slurry after ball milling was dried at 80°C under vacuum for 24 h to remove the liquid, the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was laid flat in a quartz crucible, calcined at 600°C in an air atmosphere muffle furnace for 2 h (the heating rate from room temperature to the calcination temperature was 5°C / min). After cooling to room temperature, simple grinding obtained 1.0 mol% Sr-doped p-type nano-bismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, labeled as Sr 1.0 -Bi4Ti3O 12 .
[0027] The XRD test results showed that the main crystal phase of the prepared Sr-doped p-type nano-bismuth titanate was Bi4Ti3O 12 , and the doping of Sr formed a small amount of new crystal phase Sr2Bi4Ti5O 18 .
[0028] The reaction evaluation was referred to Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 catalyst was replaced with an equal amount of the catalyst prepared in this example), and the hydrogen yield was 97.2 μmol g -1 h -1 , which was about 4 times higher than that of Comparative Example 1, indicating that Sr 1.0 -Bi4Ti3O 12 was successfully prepared.
[0029] Example 3
[0030] 5.0 mol% Ca-doped p-type nanobismuth titanate was obtained by the following process: first, 6 mmol of Ti02(anatase phase), 4 mmol of Bi203and 5.0 mol% of calcium carbonate relative to the molar amount of Bi were put into a maroon ball mill jar, 3 mL of ethanol was added, after sealing with a cover, the rotation speed was 600 rpm / min, and the mixture was fully wet-milled for 36 h. Subsequently, the slurry after ball milling was dried at 60°C under vacuum for 18 h to remove the liquid, the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was spread in an alumina crucible, calcined at 900°C in an air atmosphere muffle furnace for 1 h (the heating rate from room temperature to the calcination temperature was 10°C / min). After cooling to room temperature, simple grinding obtained 5.0 mol% Ca-doped p-type nanobismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, labeled as Ca 5.0 -Bi4Ti3O 12 .
[0031] XRD test results showed that the main crystal phase of the prepared Ca-doped p-type nanobismuth titanate was Bi4Ti3O 12 , and the doping of Ca formed a small amount of new crystal phase CaTiO3.
[0032] Reaction evaluation reference to application example 1 (different from it in that Ba 2.0 -Bi4Ti3O 12 The hydrogen yield was 92.2 μmol g -1 h -1 , about 4 times higher than that of comparative example 1, indicating that Ca 5.0 -Bi4Ti3O 12 was successfully prepared.
[0033] Example 4
[0034] 0.5 mol% Cd-doped p-type nanobismuth titanate was obtained by the following process: first, 6 mmol of Ti02(rutile phase), 4 mmol of Bi203and 0.5 mol% of cadmium carbonate relative to the molar amount of Bi were put into a maroon ball mill jar, 1 mL of methanol was added, after sealing with a cover, the rotation speed was 400 rpm / min, and the mixture was fully wet-milled for 48 h. Subsequently, the slurry after ball milling was dried at 60°C under vacuum for 18 h to remove the liquid, the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was spread in an alumina crucible, calcined at 500°C in an air atmosphere muffle furnace for 6 h (the heating rate from room temperature to the calcination temperature was 5°C / min). After cooling to room temperature, simple grinding obtained 0.5 mol% Cd-doped p-type nanobismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, labeled as Cd 0.5-Bi4Ti3O 12 .
[0035] XRD test results show that the main crystal phase of the prepared Cd-doped p-type nanometer bismuth titanate is Bi4Ti3O 12 , and the doping of Cd will form a small amount of new crystal phase CdTiO3.
[0036] Reaction evaluation refers to application example 1 (different from it is that the Ba 2.0 -Bi4Ti3O 12 The hydrogen production rate is 157.8 μmol g -1 h -1 Compared with Comparative Example 1, the hydrogen production rate is increased by about 7 times, indicating that Cd 0.5 -Bi4Ti3O 12 is successfully prepared.
[0037] Example 5
[0038] 1.0 mol% of Ni-doped p-type nanometer bismuth titanate is obtained by the following process: first, 6 mmol of TiO2 (anatase phase), 4 mmol of Bi2O3 and 1.0 mol% of cadmium carbonate relative to the molar amount of Bi are put into a agate ball mill jar, 3 mL of methanol is added, after sealing with a cover, the rotation speed is 400 rpm / min, and the mixed material is wet-milled for 48 h. Subsequently, the slurry after ball milling is dried at 60°C under vacuum for 18 h to remove the liquid, and the obtained powder sample is collected and ground with a mortar for 10 min. Finally, the powder sample is spread on an alumina crucible, and calcined in an air atmosphere muffle furnace at 750°C for 2 h (the heating rate from room temperature to the calcination temperature is 5°C / min). After cooling to room temperature, simple grinding obtains 1.0 mol% of Ni-doped p-type nanometer bismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, and is marked as Ni 1.0 -Bi4Ti3O 12 , and the doping of Ni will form a small amount of new crystal phase NiTiO3.
[0039] XRD test results show that the main crystal phase of the prepared Ni-doped p-type nanometer bismuth titanate is Bi4Ti3O 12 , and the doping of Ni will form a small amount of new crystal phase NiTiO3.
[0040] Reaction evaluation refers to application example 1 (different from it is that the Ba 2.0 -Bi4Ti3O 12 The hydrogen production rate is 160.1 μmol g -1 h -1Compared with Comparative Example 1, the hydrogen production rate is increased by about 7 times, indicating that Ni 1.0 -Bi4Ti3O 12 is successfully prepared.
[0041] Example 6
[0042] 3.0 mol% Co-doped p-type nanometer bismuth titanate is obtained by the following process: first, 6 mmol of TiO2(anatase phase), 4 mmol of Bi2O3and 3.0 mol% of cobalt acetate relative to the molar amount of Bi are put into a maroon ball mill tank, 3 mL of water is added, after sealing with a cover, the rotation speed is 400 rpm / min, and the mixture is fully wet-milled for 48 h. Subsequently, the slurry after ball milling is dried at 80°C under vacuum for 24 h to remove the liquid, the obtained powder sample is collected and fully ground with a mortar for 10 min. Finally, the powder sample is laid flat in an alumina crucible, calcined at 750°C in an air atmosphere muffle furnace for 2 h (the heating rate from room temperature to the calcination temperature is 5°C / min). After cooling to room temperature, simple grinding obtains 3.0 mol% Co-doped p-type nanometer bismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, marked as Co 3.0 -Bi4Ti3O 12 .
[0043] The XRD test results show that the main crystal phase of the prepared Co-doped p-type nanometer bismuth titanate is Bi4Ti3O 12 The doping of Co can form a small amount of new crystal phase CoTiO3.
[0044] The reaction evaluation is carried out according to Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 The hydrogen production rate is 70.9 μmol g -1 h -1 Compared with Comparative Example 1, the hydrogen production rate is increased by about 3 times, indicating that Co 3.0 -Bi4Ti3O 12 is successfully prepared.
[0045] Example 7
[0046] 1.5 mol% Pb doped p-type nanobititanate is obtained by the following process: first, 6 mmol TiO2(rutile phase), 4 mmol Bi2O3 and 1.5 mol% lead carbonate relative to the molar amount of Bi are put into a maroon ball mill jar, 3 mL of water is added, after sealing with a cover, the rotation speed is 400 rpm / min, and the mixture is fully wet-milled for 48 h. Subsequently, the slurry after ball milling is dried at 80°C under vacuum for 24 h to remove the liquid, the obtained powder sample is collected and fully ground with a mortar for 10 min. Finally, the powder sample is spread in an alumina crucible, calcined in an air atmosphere muffle furnace at 700°C for 2.5 h (the heating rate from room temperature to the calcination temperature is 5°C / min). After cooling to room temperature, simple grinding obtains 1.5 mol% Pb doped p-type nanobititanate relative to the molar amount of Bi, with a particle size of 10-100 nm, which is marked as Pb-Bi4Ti3O12. 1.5 -Bi4Ti3O 12 .
[0047] The XRD test results show that the main crystal phase of the prepared Pb doped p-type nanobititanate is Bi4Ti3O 12 , and the doping of Pb will form a small amount of new crystal phase PbBi4Ti4O 15 .
[0048] The reaction evaluation is carried out according to Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 catalyst is replaced by the catalyst prepared in this example), and the hydrogen yield is 98.4 μmol g -1 h -1 , which is about 4 times higher than that of Comparative Example 1, indicating that the Pb 1.5 -Bi4Ti3O 12 doped p-type nanobititanate is successfully prepared.
[0049] Example 8
[0050] 1.0 mol% Pb and 1.0 mol% Ba doped p-type nanobismuth titanate is obtained by the following process: first, 6 mmol of TiO2(rutile phase), 4 mmol of Bi2O3, and 1.0 mol% of lead carbonate and 1.0 mol% of barium carbonate relative to the molar amount of Bi are put into a maroon ball mill jar, 3 mL of water is added, after being sealed with a cover, the rotation speed is 400 rpm / min, and the mixture is fully wet-milled for 48 h. Subsequently, the slurry after ball milling is dried at 80°C under vacuum for 24 h to remove the liquid, the obtained powder sample is collected and fully ground with a mortar for 10 min. Finally, the powder sample is laid flat in an alumina crucible, and calcined in an air atmosphere muffle furnace at 750°C for 2 h (the heating rate from room temperature to the calcination temperature is 5°C / min). After cooling to room temperature, simple grinding obtains 1.0 mol% Pb and 1.0 mol% Ba doped p-type nanobismuth titanate relative to the molar amount of Bi, with a particle size of 10-100 nm, and is marked as Pb 1.0 Ba 1.0 -Bi4Ti3O 12 The doping of Pb and Ba forms a small amount of new crystal phase PbBi4Ti4O 15 and BaBi4Ti4O 15 .
[0051] The XRD test results show that the main crystal phase of the prepared Pb and Ba doped p-type nanobismuth titanate is Bi4Ti3O 12 .
[0052] The reaction evaluation refers to Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 catalyst is replaced with an equal amount of the catalyst prepared in this example), and the hydrogen yield is 195.6 μmol g -1 h -1 , which is about 8 times higher than that of Comparative Example 1, indicating that the Pb 1.0 Ba 1.0 -Bi4Ti3O 12 is successfully prepared.
[0053] Example 9
[0054] The p-type nano-bismuth titanate doped with 0.5 mol% of Sr, 0.5 mol% of Ba and 0.5 mol% of Cd was obtained by the following process: first, 6 mmol of TiO2(anatase phase), 4 mmol of Bi2O3and 0.5 mol% of strontium carbonate, 0.5 mol% of barium carbonate and 0.5 mol% of cadmium carbonate relative to the molar amount of Bi were put into a maroon ball mill jar, 3 mL of water was added, after being sealed with a cover, the rotation speed was 400 rpm / min, and the mixture was fully wet-milled for 48 h. Subsequently, the slurry after ball milling was dried at 80°C under vacuum for 24 h to remove the liquid, the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was laid flat in an alumina crucible, calcined at 750°C in an air muffle furnace for 2 h (the heating rate from room temperature to the calcination temperature was 5°C / min). After cooling to room temperature, simple grinding obtained the p-type nano-bismuth titanate doped with 0.5 mol% of Sr, 0.5 mol% of Ba and 0.5 mol% of Cd relative to the molar amount of Bi, with a particle size of 10-100 nm, and was marked as Sr 0.5 Ba 0.5 Cd 0.5 -Bi4Ti3O 12 .
[0055] The XRD test results show that the main crystal phase of the prepared p-type nano-bismuth titanate doped with Sr, Ba and Cd is Bi4Ti3O 12 The doping of Sr, Ba and Cd can form a small amount of new crystal phases of Sr2Bi4Ti5O 18 , BaBi4Ti4O 15 and CdTiO3.
[0056] The reaction evaluation was made with reference to Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 catalyst was replaced with an equal amount of the catalyst prepared in this example), and the hydrogen yield was 173.2 μmol g -1 h -1 , which was about 7 times higher than that of Comparative Example 1, indicating that the p-type nano-bismuth titanate doped with Sr 0.5 Ba 0.5 Cd 0.5 -Bi4Ti3O 12 was successfully prepared.
[0057] Example 10
[0058] The p-type nano-bismuth titanate doped with 0.5 mol% of Sr and 1.0 mol% of Cd was obtained by the following process: first, 6 mmol of TiO2(anatase phase), 4 mmol of Bi2O3, and 0.5 mol% of strontium carbonate and 1.0 mol% of cadmium carbonate relative to the molar amount of Bi were put into a maroon ball mill jar, 3 mL of water was added, and after being sealed with a cover, the speed was 400 rpm / min, and the mixture was fully wet-milled for 48 h. Subsequently, the slurry after ball milling was dried at 80°C under vacuum for 24 h to remove the liquid, and the obtained powder sample was collected and fully ground with a mortar for 10 min. Finally, the powder sample was laid flat in an alumina crucible, and calcined at 750°C in a muffle furnace in an air atmosphere for 2 h (the heating rate from room temperature to the calcination temperature was 5°C / min). After cooling to room temperature, simple grinding obtained the p-type nano-bismuth titanate doped with 0.5 mol% of Sr and 1.0 mol% of Cd relative to the molar amount of Bi, with a particle size of 10-100 nm, and was marked as Sr 0.5 Cd 1.0 -Bi4Ti3O 12 The doping of Sr and Cd formed a small amount of new crystal phases Sr2Bi4Ti5O 18 and CdTiO3.
[0059] The XRD test results showed that the main crystal phase of the prepared p-type nano-bismuth titanate doped with Sr and Cd was Bi4Ti3O 12 .
[0060] The reaction evaluation was based on Application Example 1 (except that the Ba 2.0 -Bi4Ti3O 12 catalyst prepared in Example 1 was replaced), and the hydrogen yield was 146.9 μmol g -1 h -1 Compared with Comparative Example 1, the hydrogen yield was increased by about 6 times, indicating that the p-type nano-bismuth titanate doped with Sr 0.5 Cd 1.0 -Bi4Ti3O 12 was successfully prepared.
[0061] Application Example 1
[0062] 10 mg of the Ba 2.0 -Bi4Ti3O 12 catalyst prepared in Example 1 was added to 1.0 ml of a 20% methanol aqueous solution by volume, and after removing the oxygen in the system, an 18W ultraviolet LED lamp was turned on, and the photocatalytic reaction was carried out under the condition of ultraviolet light source 365 nm for 3 h. After the reaction, He was added as an internal standard to quantify the generated hydrogen. Gas chromatography analysis showed that the hydrogen yield was 127.8 μmol g -1 h -1 .
[0063] Comparative Example 1
[0064] 10 mg of Bi4Ti3O12 prepared in the same way as in Example 1 but without metal doping was taken 12 The catalyst was added to 1.0 ml of a methanol aqueous solution with a volume fraction of 20%, and after removing oxygen in the system, an 18W ultraviolet LED lamp was turned on to carry out photocatalytic reaction under the condition of ultraviolet light source 365 nm for 3h. After the reaction, He was added as an internal standard to quantify the generated hydrogen. Gas chromatography analysis showed that the yield of hydrogen was 23.1 μmol g -1 h -1 .
[0065] The results show that the effect of hydrogen production by water splitting can be significantly improved by constructing metal-doped p-type nano-bismuth titanate Ba 2.0 -Bi4Ti3O 12 , and the active hydrogen production rate is about 5 times higher than that of Bi4Ti3O 12 without metal doping. It shows that Ba 2.0 -Bi4Ti3O 12 is successfully prepared. The p-type nano-bismuth titanate constructed by metal doping creates a doping level and a surface active site, promotes the separation of photo-generated carriers, and improves the activity of hydrogen production by water splitting.
Claims
1. The application of a metal-doped p-type nano-bismuth titanate in the catalytic photocatalytic water splitting process for hydrogen production, characterized in that the method... include: (1) Place TiO2, Bi2O3 and the precursor of the doped metal into a ball mill jar, add liquid grinding media, and mix thoroughly by wet milling; the doped metal is one or more of Sr, Ba, Ca, Y, Zn, Cd, Co, Ni and Pb; (2) Vacuum dry the ball-milled slurry to remove the liquid, collect the obtained powder sample and grind it into a powder sample using a mortar and pestle; (3) The powder sample was placed in a crucible and calcined in an air atmosphere muffle furnace at high temperature. After cooling, metal-doped p-type nano bismuth titanate was obtained.
2. The application according to claim 1, characterized in that, In step (1), the TiO2 is anatase phase and / or rutile phase; the molar ratio of TiO2 to Bi2O3 is 3:1 to 1:
20.
3. The application according to claim 2, characterized in that, The molar ratio of TiO2 to Bi2O3 is 3:1 to 3:
2.
4. The application according to claim 1, characterized in that, In step (1), the precursor of the doped metal is one or more of the following: doped metal carbonate, doped metal bicarbonate, and doped metal acetate; the doped metal is one or more of the following: Sr, Ba, Ca, Y, Zn, Cd, Co, Ni, and Pb, which have atomic radii smaller than Bi and have a valence of 2 and / or 1; and the molar amount of the doped metal relative to bismuth titanate is 0.1 to 10.0%.
5. The application according to claim 4, characterized in that, The molar amount of the doped metal relative to bismuth titanate is 0.1 to 5.0%.
6. The application according to claim 1, characterized in that, In step (1), the liquid grinding medium is one or more of water, methanol, and ethanol; the ratio of the volume of the solvent to the total mass of the ball-milled material, namely TiO2, Bi2O3 and the precursor of the doped metal, is 0.5~3.0 mL / g.
7. The application according to claim 1, characterized in that, In step (1), the ball milling speed is 200~800 rpm / min; the ball milling time is 12~72 h.
8. The application according to claim 7, characterized in that, In step (1), the ball milling speed is 300~600 rpm / min; the ball milling time is 36~48 h.
9. The application according to claim 1, characterized in that, In step (2), the drying temperature is 60~100 °C; the drying time is 12~36 h.
10. The application according to claim 9, characterized in that, In step (2), the drying temperature is 60~80 °C; the drying time is 18~24 h.
11. The application according to claim 1, characterized in that, In step (1), the material of the ball mill is one or more of agate and zirconium oxide; In step (3), the crucible is made of alumina and / or quartz.
12. The application according to claim 1, characterized in that, In step (3), the calcination temperature of the muffle furnace is 400~1100 °C; the calcination time is 1~12 h; and the heating rate from room temperature to the calcination temperature is 2~10 °C / min.
13. The application according to claim 12, characterized in that, In step (3), the calcination temperature of the muffle furnace is 600~800 °C; the calcination time is 2~6 h; and the heating rate from room temperature to the calcination temperature is 5~10 °C / min.