A gap-doped metal oxide and a method of making the same
By using the method of low-temperature and high-pressure gap doping of TiO2 material, the problem of narrow spectral response range of TiO2 was solved, and the material was made capable of dual absorption characteristics in the ultraviolet, visible and infrared regions, thereby improving the light energy conversion efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- UNIV OF SCI & TECH OF CHINA
- Filing Date
- 2026-05-08
- Publication Date
- 2026-07-07
AI Technical Summary
The spectral response range of existing TiO2 materials is mainly concentrated in the ultraviolet region, with low utilization of visible and infrared light. Traditional doping methods are prone to causing lattice distortion and decreased crystallinity.
By doping metal oxide lattices with H or N atoms under low temperature and high pressure conditions, the microstructure of the material is kept unchanged, and intermediate energy levels are introduced to broaden the spectral response range.
This study achieved a significant improvement in the absorption capacity of visible and infrared light by TiO2 materials without destroying their crystallinity, thereby enhancing their light energy conversion efficiency.
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Figure CN122144783B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal oxide materials technology, and in particular to an interstitial doped metal oxide and its preparation method. Background Technology
[0002] Metal oxide semiconductors, represented by TiO2, have been widely studied and applied in electrocatalysis, photocatalytic degradation, and photoelectrochemical conversion due to their chemical stability, environmental friendliness, non-toxicity, and low cost. However, as a wide-bandgap semiconductor (the bandgap of the anatase phase is approximately 3.1-3.2 eV), TiO2's spectral response range is mainly concentrated in the ultraviolet region, while its utilization rate of visible and infrared light, which account for the highest proportion of energy in sunlight, is extremely low. This severely limits its energy conversion efficiency in practical applications.
[0003] To broaden the spectral absorption range of metal oxides, researchers typically employ elemental doping. Depending on the position of the element within the crystal lattice, doping is generally categorized as substitution doping or interstitial doping. Currently, methods for preparing modified TiO2 are usually carried out at high temperatures, which can easily lead to severe lattice distortion or phase transitions. For example, while "black titanium dioxide" exhibits a wide absorption range at high temperatures, its surface lattice often tends towards amorphization, and its internal crystallinity is compromised. Furthermore, existing doping techniques can usually only slightly reduce the band gap, making it difficult to achieve significant visible / infrared light absorption by introducing controlled intermediate energy levels while maintaining ultraviolet absorption advantages.
[0004] Therefore, in-depth research on achieving stable and controllable interstitial doping without destroying the original microstructure and high crystallinity of metal oxides (such as TiO2), and thereby introducing intermediate energy levels to generate dual absorption characteristics, is of great significance for the modification of semiconductor materials. Summary of the Invention
[0005] To address the technical problems of excessively wide band gaps and low visible light utilization in metal oxides (such as TiO2), as well as the tendency of traditional substitution doping to lead to lattice distortion, decreased crystallinity, and damage to microstructure, this invention provides an interstitial doped metal oxide and its preparation method. This method is carried out under low-temperature and high-pressure conditions. By precisely controlling these conditions, this invention achieves a significant improvement in crystallinity and the introduction of intermediate energy levels through interstitial doping with H or N without altering the microstructure of the metal oxide, thereby obtaining a high-performance photoelectric / catalytic material with dual absorption characteristics.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] An interstitial doped metal oxide, wherein H or N atoms are embedded in the crystal lattice of the metal oxide as interstitial atoms, and the embedding of H or N atoms into the crystal lattice of the metal oxide does not change the crystal phase structure of the metal oxide. The metal oxide is TiO2 or CeO2.
[0008] The band gap of the interstitial doped metal oxide exhibits dual absorption characteristics, retaining the ultraviolet absorption characteristics of the metal oxide; at the same time, an intermediate energy level is introduced through interstitial doping.
[0009] The above-mentioned method for preparing interstitial doped metal oxides includes the following steps:
[0010] S1. Take the metal oxide and add it to ethanol. After stirring, centrifuging, drying and grinding in sequence, put it into a high-pressure reactor.
[0011] S2. Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 130-170℃ and maintain for 3-5 h, then cool to room temperature;
[0012] S3. Introduce the reaction gas into the high-pressure reactor, and then let it stand for at least 20 minutes; the reaction gas is H2 or N2.
[0013] S4. Raise the temperature of the high-pressure reactor to 200-300℃ and maintain it for 24-96 hours;
[0014] S5. Cool the high-pressure reactor to room temperature, depressurize it to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide.
[0015] In step S3, when the reaction gas is H2, H2 is introduced until the pressure in the high-pressure reactor is 7-8 MPa.
[0016] In step S3, when the reaction gas is N2, N2 is introduced until the pressure in the high-pressure reactor is 10-12 MPa.
[0017] In step S1, the ratio of metal oxide to ethanol is 40-60 mL of ethanol per 500 mg of metal oxide.
[0018] The heating rate in steps S2 and S4 is 3-5 °C / min.
[0019] The beneficial effects of this invention are as follows:
[0020] (1) This invention achieves interstitial doping of H or N atoms by precisely controlling the low temperature and high pressure environment. While fully preserving the microstructure of metal oxides (e.g., TiO2) (e.g., the original 10 nm spherical shape of TiO2) and the lattice framework, it not only avoids the lattice distortion, morphology collapse and surface amorphization caused by traditional substitution doping or high temperature reduction methods, but also significantly enhances the crystallinity of the material through an effect similar to "pressure annealing".
[0021] (2) This invention endows the material with unique dual absorption characteristics. While maintaining the advantage of ultraviolet light absorption, it introduces a controlled intermediate energy level through interstitial atoms, induces a narrow bandgap transition of about 1.0 eV, thereby greatly expanding the spectral response range to the visible and infrared regions and significantly improving the light energy conversion efficiency.
[0022] (3) This invention effectively alleviates the strain when atoms enter the crystal lattice by precisely controlling the temperature and pressure, ensuring the uniformity and stability of doping. Moreover, the process is simple, environmentally friendly and highly repeatable, providing an innovative approach for preparing high-performance, broad-spectrum absorption metal oxide materials. Attached Figure Description
[0023] Figure 1 The XRD patterns are of HTiO2 prepared in Example 1, NTiO2 prepared in Example 2, and raw material TiO2.
[0024] Figure 2 The images show SEM and TEM images of HTiO2 prepared in Example 1, NTiO2 prepared in Example 2, and raw material TiO2; wherein... Figure 2 Image (a) is a SEM image of the raw material TiO2. Figure 2 Image (b) is a SEM image of HTiO2 prepared in Example 1. Figure 2 Image (c) in the image is a SEM image of NTiO2 prepared in Example 2. Figure 2 Image (d) in the image is a TEM image of the raw material TiO2. Figure 2 Image (e) in the image is a TEM image of HTiO2 prepared in Example 1. Figure 2 (f) is a TEM image of NTiO2 prepared in Example 2.
[0025] Figure 3 XPS images of HTiO2 prepared in Example 1, NTiO2 prepared in Example 2, and raw material TiO2; Figure 3 (a) in the diagram is the binding energy spectrum of the Ti 2p orbital electrons. Figure 3 (b) in the spectrum is the O 1s energy spectrum. Figure 3 (c) in the figure is the N 1s energy spectrum of NTiO2 prepared in Example 2.
[0026] Figure 4 The UV-Vis spectra and Tauc plots of HTiO2 prepared in Example 1, NTiO2 prepared in Example 2, and raw material TiO2 are shown. Figure 4 (a) in the image is the UV-vis map. Figure 4 Figure (b) in the diagram is a Tauc diagram.
[0027] Figure 5 The XRD patterns are of HCaO2 prepared in Example 3, NCaO2 prepared in Example 4, and raw material CeO2.
[0028] Figure 6 The images show SEM and TEM images of HCaO2 prepared in Example 3, NCaO2 prepared in Example 4, and raw material CeO2; wherein... Figure 6 Image (a) is a SEM image of the raw material CeO2. Figure 6 Image (b) is a SEM image of HCaO2 prepared in Example 3. Figure 6 Image (c) in the image is a SEM image of NCEO2 prepared in Example 4. Figure 6 Image (d) in the image is a TEM image of the raw material CeO2. Figure 6 Image (e) in the image is a TEM image of HCaO2 prepared in Example 3. Figure 6 (f) is a TEM image of NCEO2 prepared in Example 4.
[0029] Figure 7 XPS images of HCaO2 prepared in Example 3, NCaO2 prepared in Example 4, and raw material CeO2; Figure 7 (a) in the diagram is the binding energy spectrum of the Ce 3d orbital electrons. Figure 7 (b) in the spectrum is the O 1s energy spectrum. Figure 7 (c) in the figure is the N 1s energy spectrum of NCEO2 prepared in Example 4.
[0030] Figure 8 The UV-Vis and Tauc images are of HCaO2 prepared in Example 3, NCaO2 prepared in Example 4, and raw material CeO2; wherein Figure 8 (a) in the image is the UV-vis map. Figure 8 Figure (b) in the diagram is a Tauc diagram. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0032] The interstitial doped metal oxide of the present invention is prepared under low temperature and high pressure conditions, that is, the interstitial doped metal oxide is obtained by incorporating H or N atoms into the interstitial space of the crystal lattice through a low temperature and high pressure method; the material improves the crystallinity of the crystal while maintaining the original microstructure of the metal oxide semiconductor (TiO2 or CeO2); the electronic structure of the material has dual absorption characteristics: its intrinsic band gap is reduced from 3.1 eV to 3.0 eV (retaining ultraviolet absorption), while an intermediate energy level is introduced through interstitial atoms, resulting in a narrow band gap transition of about 1.0 eV (broadened to visible and infrared absorption).
[0033] The preparation steps of the above-mentioned interstitial doped metal oxide specifically include the following steps:
[0034] S1. Take the metal oxide and add it to ethanol. After stirring for 3 hours, centrifuge, dry, grind, and then put it into a high-pressure reactor.
[0035] S2. Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 130-170 ℃ and maintain for 3-5 h, then slowly lower to room temperature;
[0036] S3. Introduce H2 into the high-pressure reactor until the pressure is 7-8 MPa (or introduce N2 until the pressure is 10-12 MPa), and let it stand until room temperature.
[0037] S4. Raise the temperature of the high-pressure reactor to 200-300℃ and maintain it for 24-96 hours;
[0038] S5. Slowly reduce the temperature of the high-pressure reactor to room temperature, depressurize to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide.
[0039] In step S1, the ratio of metal oxide to ethanol is 40-60 mL of ethanol for every 500 mg of metal oxide; the grinding is done by hand in an agate mortar for 1 min to ensure the looseness of the powder while maintaining the dryness of the metal oxide powder.
[0040] In step S2, the heating rate to 150℃ is 3-5℃ / min, and the temperature is maintained for 4 hours to prevent abrupt changes in lattice stress and to effectively remove adsorbed molecules and N2 / O2 gas molecules from the surface.
[0041] In step S3, after H2 or N2 gas is introduced, it needs to stand for at least 20 minutes, and the pressure at room temperature should be 7-8 MPa and 10-12 MPa, respectively.
[0042] In step S4, the heating rate to 200-300℃ is 3-5℃ / min to prevent abrupt changes in lattice stress. The H2 or N2 gas pressure after heating should be 12-14 MPa or 17-19 MPa, respectively, to promote H or N doping into the metal oxide.
[0043] The interstitial doped metal oxide prepared by this invention exhibits dual absorption characteristics in its band gap. It not only retains the ultraviolet absorption of the metal oxide, but also introduces an intermediate energy level through interstitial doping, thus obtaining a narrow band gap transition of about 1.0 eV.
[0044] Example 1:
[0045] A method for preparing an interstitial doped metal oxide includes the following steps:
[0046] S1: Take 10 nm anatase TiO2 as raw material, add it to ethanol, stir for 3 h, centrifuge, dry, grind, and put it into a high-pressure reactor; 40 mL of ethanol is added for every 500 mg TiO2;
[0047] S2: Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 150℃ and maintain for 4 h, then slowly lower it to room temperature;
[0048] S3: Introduce H2 into the high-pressure reactor until the pressure reaches 7.6 MPa, and let it stand at room temperature for 20 minutes;
[0049] S4: Raise the temperature of the high-pressure reactor to 200℃ and maintain it for 48 hours;
[0050] S5: Slowly reduce the temperature of the high-pressure reactor to room temperature, depressurize to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide, denoted as HTiO2.
[0051] Example 2:
[0052] A method for preparing interstitial doped metal oxides under low temperature and high pressure conditions includes the following steps:
[0053] S1: Take 10 nm anatase TiO2 and add it to ethanol. After stirring for 3 h, centrifuge, dry, grind, and put it into a high-pressure reactor; 60 mL of ethanol is added for every 500 mg TiO2.
[0054] S2: Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 130℃ and maintain for 5 h, and then slowly lower it to room temperature;
[0055] S3: Introduce N2 into the high-pressure reactor until the pressure reaches 11.7 MPa, and allow it to stand until room temperature;
[0056] S4: Raise the temperature of the high-pressure reactor to 300℃ and maintain it for 24 hours;
[0057] S5: Slowly reduce the temperature of the high-pressure reactor to room temperature, depressurize to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide, denoted as NTiO2.
[0058] Example 3:
[0059] A method for preparing interstitial doped metal oxides under low temperature and high pressure conditions includes the following steps:
[0060] S1: Take 20 nm CeO2 as raw material and add it to ethanol. After stirring for 3 h, centrifuge, dry, grind, and put it into a high-pressure reactor; 50 mL of ethanol is added for every 500 mg CeO2.
[0061] S2: Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 170°C and maintain for 3 h, and then slowly lower it to room temperature;
[0062] S3: Introduce H2 into the high-pressure reactor until the pressure reaches 7.4 MPa, and allow it to stand until room temperature;
[0063] S4: Raise the temperature of the high-pressure reactor to 200℃ and maintain it for 96 hours;
[0064] S5: Slowly reduce the temperature of the high-pressure reactor to room temperature, depressurize to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide, denoted as HCaO2.
[0065] Example 4:
[0066] A method for preparing interstitial doped metal oxides under low temperature and high pressure conditions includes the following steps:
[0067] S1: Take 10 nm CeO2 as raw material and add it to ethanol. After stirring for 4 hours, centrifuge, dry, grind, and put it into a high-pressure reactor; 40 mL of ethanol is added for every 500 mg CeO2.
[0068] S2: Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 150°C and maintain for 4 h, and then slowly lower it to room temperature;
[0069] S3: Introduce N2 into the high-pressure reactor until the pressure reaches 11.6 MPa, and allow it to stand until room temperature;
[0070] S4: Raise the temperature of the high-pressure reactor to 200℃ and maintain it for 48 hours;
[0071] S5: Slowly reduce the temperature of the high-pressure reactor to room temperature, depressurize to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide, denoted as NCEO2.
[0072] The interstitial doped metal oxides and raw material TiO2 (10 nm anatase TiO2) prepared in Examples 1 and 2, as well as the interstitial doped metal oxides and raw material CeO2 prepared in Examples 3 and 4, were characterized and tested. The results are as follows:
[0073] Figure 1 These are the XRD patterns of HTiO2 from Example 1, NTiO2 from Example 2, and the raw material TiO2. Figure 1 As can be seen, compared with the raw material TiO2, the characteristic peak positions of the doped HTiO2 and NTiO2 samples are completely consistent with those of anatase TiO2 (PDF#73-1764), indicating that the low-temperature high-pressure process of the present invention has not changed the crystal phase structure of the metal oxide. At the same time, it was observed that the diffraction peak intensities of HTiO2 and NTiO2 were enhanced and the peak shapes were sharper than those of the original TiO2, proving that the low-temperature high-pressure process has an effect similar to "pressure annealing", which significantly improves the crystallinity of TiO2.
[0074] Figure 2 The images shown are SEM and TEM images of HTiO2 from Example 1, NTiO2 from Example 2, and raw material TiO2. Figure 2 Image (a) is a SEM image of the raw material TiO2. Figure 2 Image (b) is a SEM image of HTiO2 prepared in Example 1. Figure 2 Image (c) in the image is a SEM image of NTiO2 prepared in Example 2. Figure 2 Image (d) in the image is a TEM image of the raw material TiO2. Figure 2 Image (e) in the image is a TEM image of HTiO2 prepared in Example 1. Figure 2 Image (f) is a TEM image of NTiO2 prepared in Example 2. From... Figure 2 Morphological observation shows that HTiO2 and NTiO2, after low-temperature and high-pressure interstitial doping, still maintain the same approximately 10nm spherical microstructure as the original TiO2, with uniform particle distribution and no particle agglomeration, sintering, or morphological collapse phenomena commonly seen in high-temperature doping. This further confirms that the interstitial doping technology described in this invention can perfectly preserve the microstructure characteristics of the matrix material while significantly optimizing the electronic structure and optical properties of the material.
[0075] Figure 3 These are XPS images of HTiO2 from Example 1, NTiO2 from Example 2, and raw material TiO2 of the present invention. Figure 3 (a) in the diagram is the binding energy spectrum of the Ti 2p orbital electrons. Figure 3 (b) in the spectrum is the O 1s energy spectrum. Figure 3 (c) in the figure represents the N 1s energy spectrum of NTiO2 prepared in Example 2. Figure 3 From the O 1s energy spectrum of (b), it can be seen that lattice oxygen (O L The dominance of this element indicates structural stability. Figure 3 In the N 1s energy spectrum of (c) NTiO2, it can be seen that the characteristic peak is located at around 400 eV, rather than the 396-397 eV (Ti-N bond) that usually appears in non-substitution doping. This strongly proves that N atoms exist in the TiO2 lattice as interstitial atoms, rather than replacing O atoms in the lattice.
[0076] Figure 4 The images show the UV-Vis and Tauc patterns of HTiO2 from Example 1, NTiO2 from Example 2, and raw material TiO2. Figure 4 (a) in the image is the UV-vis map. Figure 4 Figure (b) in the diagram is a Tauc diagram. (From...) Figure 4 It can be seen that the interstitial doped sample exhibits obvious dual absorption characteristics: in the ultraviolet region, the intrinsic band gap is reduced from 3.1 eV of the original TiO2 to 3.0 eV, retaining the ultraviolet response capability of the substrate material; more importantly, due to the introduction of interstitial atoms, an intermediate energy level is formed, which induces a narrow band gap transition of about 1.0 eV in the long wavelength range, thus successfully broadening the light absorption range of the material to the visible and infrared light regions.
[0077] Figure 5 The XRD patterns are of HCaO2 from Example 3, NCaO2 from Example 4, and raw material CeO2. Figure 5 The results showed that the characteristic peak positions of the treated HCaO2 and NCaO2 samples were completely consistent with those of cubic fluorite CeO2 (PDF#75-0076), proving that the low-temperature high-pressure interstitial doping process did not change the crystal phase structure of the matrix material. Meanwhile, due to the effect similar to "pressure annealing" of this process, the diffraction peaks of the doped samples were sharper and significantly more intense than those of the original CeO2, indicating that the crystallinity of the material was effectively improved.
[0078] Figure 6 The images show SEM and TEM images of HCaO2 from Example 3, NCaO2 from Example 4, and the raw material CeO2. Figure 6 Image (a) is a SEM image of the raw material CeO2. Figure 6 Image (b) is a SEM image of HCaO2 prepared in Example 3. Figure 6 Image (c) in the image is a SEM image of NCEO2 prepared in Example 4. Figure 6Image (d) in the image is a TEM image of the raw material CeO2. Figure 6 Image (e) in the image is a TEM image of HCaO2 prepared in Example 3. Figure 6 Image (f) in the image is a TEM image of NCEO2 prepared in Example 4. From... Figure 6 As can be seen, HCaO2 and NCaO2 maintain the same spherical nanostructure as the original sample, with uniform particle distribution and a particle size of approximately 10-20 nm. During the low-temperature and high-pressure processing, the material did not exhibit particle agglomeration, sintering, or morphological collapse phenomena commonly seen in high-temperature doping. This confirms that interstitial doping technology can perfectly preserve the original microstructure of the matrix material while significantly optimizing the electronic structure.
[0079] Figure 7 XPS images of HCaO2 from Example 3, NCaO2 from Example 4, and raw material CeO2. Figure 7 (a) in the diagram is the binding energy spectrum of the Ce 3d orbital electrons. Figure 7 (b) in the spectrum is the O 1s energy spectrum. Figure 7 (c) in the image shows the N 1s energy spectrum of NCEO2 from Example 4. The N 1s energy spectrum of NCEO2 (...) Figure 7 In (c) of the sample, the characteristic peak is clearly located at around 400 eV, rather than the 396-397 eV region (corresponding to Ce-N bonds) that is usually found in traditional substitution doping. This shift strongly proves that the N atoms are embedded in the CeO2 lattice as interstitial atoms, rather than replacing the oxygen atoms in the lattice, thus adjusting the chemical environment of the material without destroying the main framework.
[0080] Figure 8 The images show the UV-Vis and Tauc patterns of HCaO2 from Example 3, NCaO2 from Example 4, and the raw material CeO2; where... Figure 8 (a) in the image is the UV-vis map. Figure 8 Figure (b) in the diagram is a Tauc diagram. Figure 8 This reflects a significant improvement in the optical properties of the material. The interstitial doped sample exhibits a distinct dual absorption characteristic: in the ultraviolet region, its intrinsic band gap is reduced from 3.0 eV in the original sample to 2.9 eV, retaining excellent ultraviolet response capability; in addition, due to the intermediate energy level formed by the introduction of interstitial atoms, a narrow band gap transition of about 1.0 eV is induced, which successfully broadens the light absorption range of the material to the visible and infrared regions, achieving a full-spectrum response.
[0081] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention. The above embodiments are provided only for the purpose of describing the present invention and are not intended to limit the present invention. Parts not described in detail in this specification are well-known in the art and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principle of the present invention should be covered within the scope of the present invention.
Claims
1. An interstitial doped metal oxide, characterized in that, In the interstitial doped metal oxide, H or N atoms are embedded in the lattice of the metal oxide as interstitial atoms, and the crystal phase structure of the metal oxide is not changed after the H or N atoms are embedded in the lattice of the metal oxide. The metal oxide is either TiO2 or CeO2; The interstitial doped metal oxide is prepared by the following method: S1. Take the metal oxide and add it to ethanol. After stirring, centrifuging, drying and grinding in sequence, put it into a high-pressure reactor. S2. Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 130-170℃ and maintain for 3-5 h, then cool to room temperature; S3. Introduce the reaction gas into the high-pressure reactor and let it stand for at least 20 minutes. When the reaction gas is H2, introduce H2 until the pressure in the high-pressure reactor is 7-8 MPa. When the reaction gas is N2, introduce N2 until the pressure in the high-pressure reactor is 10-12 MPa. S4. Raise the temperature of the high-pressure reactor to 200-300 ℃ and maintain it for 24-96 h; S5. Cool the high-pressure reactor to room temperature, depressurize it to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide.
2. The interstitial doped metal oxide according to claim 1, characterized in that, The band gap of the interstitial doped metal oxide exhibits dual absorption characteristics, retaining the ultraviolet absorption characteristics of the metal oxide; at the same time, an intermediate energy level is introduced through interstitial doping.
3. The method for preparing the interstitial doped metal oxide according to claim 1 or 2, characterized in that, Includes the following steps: S1. Take the metal oxide and add it to ethanol. After stirring, centrifuging, drying and grinding in sequence, put it into a high-pressure reactor. S2. Evacuate the high-pressure reactor to less than 1 Pa and maintain for 1 h, then raise the temperature to 130-170℃ and maintain for 3-5 h, then cool to room temperature; S3. Introduce the reaction gas into the high-pressure reactor and let it stand for at least 20 minutes. When the reaction gas is H2, introduce H2 until the pressure in the high-pressure reactor is 7-8 MPa. When the reaction gas is N2, introduce N2 until the pressure in the high-pressure reactor is 10-12 MPa. S4. Raise the temperature of the high-pressure reactor to 200-300 ℃ and maintain it for 24-96 h; S5. Cool the high-pressure reactor to room temperature, depressurize it to atmospheric pressure, and then remove the powder to obtain the interstitial doped metal oxide.
4. The method for preparing interstitial doped metal oxides according to claim 3, characterized in that, In step S1, the ratio of metal oxide to ethanol is 40-60 mL of ethanol per 500 mg of metal oxide.
5. The method for preparing interstitial doped metal oxides according to claim 3, characterized in that, The heating rate in steps S2 and S4 is 3-5℃ / min.