AuPtrGOg-C3N4 composite photocatalytic material and its preparation method

Abstract

This invention belongs to the field of nanomaterials and photocatalysis technology, and discloses composite photocatalytic materials, their preparation methods, and applications in low-light environments within a sealed chamber. These materials include graphite-like carbon nitride, rGO (reduced graphene oxide), and AuPt (gold-platinum bimetallic) nanoparticles. This invention constructs a ternary composite photocatalytic material with a two-dimensional nanosheet structure as the catalytic host. It combines this with in-situ reduced rGO to construct an efficient electron transport channel, and integrates AuPt bimetallic active sites to form a synergistic catalytic system. This effectively broadens the visible light response range, significantly suppresses photogenerated carrier recombination, improves charge separation efficiency and quantum efficiency, and leverages the surface plasmon resonance effect of Au to enhance weak light absorption and the high activity of Pt to accelerate pollutant decomposition. This fundamentally solves the defects of traditional catalysts, such as low catalytic activity and poor weak light response, endowing the material with excellent intrinsic photocatalytic performance.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials and photocatalysis technology, specifically... Composite photocatalytic materials, their preparation methods, and their applications in low-light environments within enclosed chambers. Background Technology

[0002] Enclosed spaces such as manned spacecraft cabins, deep-sea submersible cabins, and submarine cabins have poor air circulation. Interior materials, human metabolic products, and electrical equipment continuously release gaseous pollutants such as formaldehyde, benzene compounds, and total volatile organic compounds (TVOCs). Long-term accumulation of these pollutants leads to a continuous deterioration of air quality, directly threatening the health and safety of personnel. Therefore, there is an urgent need for efficient, safe, and pollution-free air purification technologies to achieve long-term purification of gaseous pollutants within the cabin. Photocatalytic oxidation technology, due to its advantages of low energy consumption, mild reaction conditions, and thorough purification, has become the preferred technology for air purification in enclosed cabins. However, traditional photocatalysts generally suffer from drawbacks in the low-light environment of enclosed cabins, including rapid photogenerated carrier recombination rates, low quantum efficiency, and weak visible light response, failing to achieve efficient degradation of gaseous pollutants and thus failing to meet the actual purification needs of enclosed cabins.

[0003] To improve the catalytic performance of photocatalysts, existing technologies mostly employ modification methods such as loading a single noble metal or constructing a binary composite system. While these modification methods can enhance the light absorption performance of materials and promote the separation of photogenerated charges to a certain extent, thus slightly improving the degradation effect of pollutants, they still have significant technical limitations. The ability of single noble metals and binary composite systems to capture and utilize weak light is insufficient, and the improvement in catalytic performance under low-illuminance conditions in a closed chamber is limited. At the same time, there is a lack of systematic design for the special environment of low light and low ventilation in a closed chamber, making it impossible to balance high catalytic activity and long-term cycle stability, and making it difficult to achieve efficient and long-lasting purification of formaldehyde, benzene series compounds, and TVOC. Summary of the Invention

[0004] To address the problems mentioned in the background section, the present invention provides... Composite photocatalytic materials and their preparation methods, and their applications in low-light environments within enclosed chambers, including... (Graphite-like carbon nitride), rGO (reduced graphene oxide), and AuPt (gold-platinum bimetallic) nanoparticles; The nanosheet structure, which was ultrasonically exfoliated for 8 hours, was used as the main semiconductor for photocatalytic reaction. rGO is composed of GO (graphene oxide) and Mixed at a mass ratio of 99:1 to 90:10, corresponding to an rGO mass fraction of 1 to 10 wt%, and reduced in situ by hydrothermal reaction at 160℃ for 8 hours; AuPt nanoparticles are alloys or core-shell structures with an Au (gold) to Pt (platinum) atomic ratio of 2:1, with a total loading of 0.5~3.0 wt%, particle size of 2~8 nm, and uniformly dispersed in... Composite surface; The material achieves efficient degradation of gaseous pollutants under weak light through a ternary synergistic effect: Au surface plasmon resonance enhances weak light absorption, rGO electron transport channels reduce photogenerated carrier recombination, and Pt active sites accelerate pollutant decomposition.

[0005] Preferably, it includes the following steps: (1): Preparation Nanosheets: Melamine powder was placed in a covered crucible and calcined at 550°C for 4 hours in air atmosphere at a rate of 5°C / min. After cooling, the powder was ground and ultrasonically exfoliated for 8 hours to obtain nanosheets. Nanosheets; (2): Preparation Composite matrix: Nanosheets and GO were mixed at a mass ratio of 99:1 to 90:10, corresponding to an rGO mass fraction of 1 to 10 wt%. Deionized water was added and ultrasonically dispersed for 30 min. The mixture was then transferred to a high-pressure reactor and hydrothermally reacted at 160 °C for 8 h. After centrifugation and drying, the composite matrix was obtained. (3): Deposition of AuPt bimetallic particles: The composite matrix is ​​dispersed in deionized water, and chloroauric acid is added ( ) and chloroplatinic acid ( Mixed solution, and The molar ratio was 2:1, and the mixture was sonicated for 10 minutes under ice-water bath and nitrogen protection. Sodium borohydride was then added. ), The mixture was stirred for 1.5 hours with a molar ratio of 15:1 to a precious metal, then centrifuged, washed, and vacuum dried to obtain the target material.

[0006] Preferably, step 1) involves preparing a two-dimensional nanosheet structure by high-temperature calcination combined with ultrasonic exfoliation.

[0007] Preferably, in step 2), the hydrothermal reaction achieves in-situ reduction of GO; in step 3), the ice-water bath and nitrogen protection are used to suppress the oxidation and agglomeration of metal particles.

[0008] Preferably, the application is for the catalytic degradation of gaseous pollutants within a sealed chamber; The sealed compartments include manned spacecraft compartments and deep-sea submersible / submarine compartments, with an internal light intensity of 50-500. When applying the material, it is coated onto the cabin walls.

[0009] Preferably, the gaseous pollutants include formaldehyde, benzene compounds, and total volatile organic compounds (TVOC); under 200 Lux conditions, the material's formaldehyde degradation rate... 96.8% degradation rate of benzene series compounds 89.2% of the total TVOC removal rate 91.5%.

[0010] Preferably, after the material is used 10 times, the formaldehyde degradation rate is [not specified]. 92.5%; precious metal leaching rate 0.5%.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention constructs Ternary composite photocatalytic materials with two-dimensional nanosheet structures Using Au as the catalyst host, it is combined with rGO generated by in-situ reduction to construct an efficient electron transport channel, and combined with AuPt bimetallic active sites to form a synergistic catalytic system; it effectively broadens the visible light response range, significantly suppresses photogenerated carrier recombination, improves charge separation efficiency and quantum efficiency, and relies on the surface plasmon resonance effect of Au to enhance weak light absorption and the high activity of Pt to accelerate pollutant decomposition. It fundamentally solves the defects of low catalytic activity and poor weak light response of traditional catalysts, and endows the material with excellent intrinsic photocatalytic performance.

[0012] Furthermore, the preparation method of the present invention is simple, has mild reaction conditions, and is highly controllable. It utilizes high-temperature calcination combined with ultrasonic exfoliation to prepare materials with high specific surface area. The nanosheets are generated by in-situ reduction of GO to rGO via hydrothermal reaction, which effectively avoids the stacking of material sheets and ensures tight interfacial bonding. AuPt bimetal is reduced and deposited under ice-water bath and nitrogen protection to achieve uniform nanoparticle size and dispersion, eliminating the agglomeration of precious metals. The entire preparation process does not require complex equipment, is low in cost, has good repeatability, and is suitable for industrial-scale production.

[0013] Furthermore, the composite photocatalytic material of this invention is perfectly suited to the special working conditions of low light and low ventilation in enclosed cabins with a light level of 50-500 Lux. It has a high efficiency in degrading formaldehyde, benzene series compounds, and TVOC, with a fast degradation rate, high mineralization degree, and excellent carbon dioxide conversion rate. At the same time, the material has outstanding cycle stability, maintaining high catalytic activity after 10 cycles of use. The leaching rate of precious metals is extremely low, and the degradation products are only carbon dioxide and water, with no secondary pollution, making it safe and environmentally friendly. It combines high catalytic activity with long-term use stability, and can achieve efficient, long-lasting, and thorough purification of gaseous pollutants in enclosed spaces such as manned spacecraft, submarines, and deep-sea submersibles, fully meeting the air purification needs of special enclosed scenarios. Attached Figure Description

[0014] Figure 1 For the present invention Schematic diagram of the synthesis process of composite photocatalytic materials; Figure 2 For the present invention Comparison chart of multi-weak light environment intensity adaptation test of composite photocatalytic materials. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1: AuPt / rGO / Basic preparation and performance verification of composite photocatalytic materials 1) Material preparation Nanosheets were prepared by weighing 5.0 g of melamine powder and placing it in a covered alumina crucible. The crucible was heated to 550 °C at a heating rate of 5 °C / min under air atmosphere and held at that temperature for 4 hours. After natural cooling to room temperature, the cooled solid was ground into a uniform powder. 200 mL of deionized water was added, and the mixture was ultrasonically treated for 8 hours (200 W power, 40 kHz frequency) to obtain nanosheets that had been ultrasonically exfoliated for 8 hours. The nanosheet suspension was centrifuged (8000 rpm, 10 min), the precipitate was collected, and vacuum dried (60℃, 12 h) for later use. 2) Preparation of rGO / The composite matrix, weigh 0.1g of the above... Nanosheets (corresponding to GO and A mass ratio of 1:99 (i.e., 1 wt% rGO) was mixed with 0.001 g of graphene oxide (GO, prepared beforehand using the Hummers method), and 50 mL of deionized water was added. The mixture was ultrasonically dispersed for 30 min (300 W) until a homogeneous suspension was formed. The suspension was transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reactor and hydrothermally reacted at 160 °C for 8 h (autogenous pressure, no reducing agent). After natural cooling, the mixture was centrifuged (10000 rpm, 15 min), washed three times with deionized water, and vacuum dried (60 °C, 12 h) to obtain rGO / Composite matrix; 3) Deposit AuPt bimetallic particles. Weigh 0.1g of the above composite matrix, disperse it in 50mL of deionized water, and add... (Jin Yuan, (Concentration 0.02 mmol / L) and (Platinum source, A mixed solution with a concentration of 0.01 mmol / L. and (Molar ratio 2:1), sonicate for 10 minutes until homogeneous, and add dropwise under ice-water bath (0-5℃) and nitrogen protection. solution ( The mixture was prepared fresh (with a total molar ratio of 15:1 to the total precious metals), and stirred for 1.5 h (500 rpm). The precipitate was collected by centrifugation (12000 rpm, 20 min), washed with deionized water until neutral, and then vacuum dried (60℃, 12 h) to obtain AuPt / rGO / Composite photocatalytic material (total AuPt loading 0.5wt%, particle size 2-8nm); 4) Performance verification: The above-mentioned finished material was uniformly coated onto the simulated wall surface of a sealed chamber, with the effective adhesion area controlled at 0.1. Relying on 1 A standardized, sealed simulated cabin was constructed to replicate the actual service conditions of a manned, enclosed space, including pre-installed piping, pressure stabilization devices, and LED uniform lighting. The cabin's initial formaldehyde concentration was preset to 2.0. Initial toluene concentration 1.0 The system is equipped with a micro-dynamic air intake system that uniformly replenishes the TVOC mixture, maintaining a static closed-loop air circulation within the cabin throughout the entire process, without any active air exchange disturbance; the light source uses dedicated visible LED lights, precisely controlling the cabin's baseline illuminance to 200 lux. This corresponds to a visible light power density of approximately 0.05. It perfectly matches the ambient lighting requirements of a typical manned enclosed cabin. 5) Degradation effect test: After continuous constant temperature and volume, sealed and static reaction with light for 150 minutes, gas phase samples were collected simultaneously in the chamber for item-by-item testing. The core measured degradation efficiency data are as follows: Under standard low light conditions of 200 Lux, the formaldehyde degradation rate was 96.8%, the toluene degradation rate was 89.2%, and the overall TVOC removal rate was 91.5%. The mineralization conversion rate was 80.3%, and the apparent first-order reaction rate of formaldehyde degradation was calculated to be 0.0228. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the final products of the catalytic reaction were only carbon dioxide and clean water, with no aldehydes, benzene intermediates, or toxic byproducts precipitated throughout the process. After a single complete service cycle, the material surface morphology and active sites showed no signs of deactivation. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the circulating air within the chamber, and the leaching rate of trace amounts of precious metals was measured. 0.5%, which meets the safety access standards for manned enclosed spaces.

[0017] Example 2: Parameter gradient control, GO and Quality ratio optimization and effect comparison The overall preparation process, temperature control parameters, material purity, and reaction equipment in this embodiment are completely consistent with those in Example 1. Only the core ratio variables are optimized. The other pre-preparation, in-situ compounding, bimetallic low-temperature reduction, and post-processing purification procedures are not adjusted differently. Only the composite matrix preparation process was optimized, and the relationship between GO and The mass ratio is 5:95, corresponding to an actual mass fraction of rGO in the composite system of 5wt%; accurately weigh 0.1g of high-purity rGO. Nanosheets were combined with 0.005g of pretreated graphene oxide powder, and a complete set of standard procedures were followed, including 300W high-power homogenous ultrasonic dispersion, in-situ water thermal compounding at 160℃ for 8 hours, gradient centrifugation purification, and drying, to stably prepare a highly conductive continuous network structure. The composite matrix was optimized, and the subsequent AuPt bimetallic loading deposition and low-temperature protective reduction processes were strictly replicated with the fixed parameters of Example 1, finally producing an optimized composite photocatalytic material with equal particle size and high dispersion. Performance comparison, using the same model as Example 1 Degradation effect under rigorous retesting in a sealed chamber, under 200 Lux low-light baseline, and with pollutant gas source of the same origin and concentration: Degradation rate improved: Formaldehyde degradation rate increased to 97.5%, a 0.7% improvement compared to the in-situ rate in Example 1; Toluene targeted degradation rate increased to 90.1%, a 0.9% improvement compared to the in-situ rate; Overall TVOC purification rate increased to 92.3%, a 0.8% improvement compared to the in-situ rate. Cause analysis: After rGO is adjusted to the optimal range of 5wt%, the two-dimensional continuous electron conduction network inside the material is densified and formed, which can quickly conduct photogenerated carriers, block the interface composite circuit, and strengthen the three-phase interface synergistic coupling effect, fully verifying the core technical mechanism of rGO exclusive electron transport noise reduction, quality improvement and efficiency enhancement.

[0018] Example 3: Long-term cycling stability and adaptation to multiple weak light intensities Long-term cycle stability testing was conducted using the material prepared in Example 1, and a fixed replica was performed. Sealed closed-loop cabin, 200 Under standard low light and fixed pollutant concentration gas source operating conditions, repeated pollutant degradation, material recovery, and regeneration cycle experiments were conducted (pollutant was introduced for 2 hours and ventilation regeneration for 1 hour in each cycle), for a total of 10 cycles: Degradation rate retention: After 10 long-term service cycles, the core purification efficiency of the material has a controllable decline and excellent stability. The steady-state degradation rate of formaldehyde remains stable at 92.5%, with only a slight decrease in efficiency compared to the initial service. The targeted degradation rate of toluene remains at 88.0%, and the overall TVOC removal rate remains stable at 90.0%, with no significant drop in efficiency. Precious metal leaching rate: After 10 cycles, the precious metal content in the air medium in the chamber was detected by ICP-MS (inductively coupled plasma mass spectrometry). The precious metal leaching rate was strictly controlled within <0.5%, with no risk of secondary pollution. Structural stability: Simultaneous microscopic characterization using SEM showed that the AuPt bimetallic active particles remained uniformly anchored and dispersed on the surface of the composite matrix, without agglomeration, detachment, or migration. The structure exhibited excellent long-term stability. This was achieved by relying on the pre-designed ice-water low-temperature bath and high-purity nitrogen inert protection process in Example 1, which avoids the potential for bimetallic particle agglomeration failure from the source.

[0019] Multi-low light environment intensity adaptation test, using 1 The test was conducted in a standard sealed chamber, with an initial formaldehyde concentration of 2.0. Initial toluene concentration 1.0 The light source is LED visible light (visible light power density approximately 0.05). The catalytic degradation performance of the material in Example 1 was tested under full-gradient low light conditions of 50 Lux (extreme low illuminance), 200 Lux (standard illuminance in the cabin), and 500 Lux (maximum low illuminance) for 150 min of illumination. The mineralization efficiency and reaction kinetic parameters were also tested simultaneously. 50 Under extreme low-light conditions: the material can still autonomously trigger a catalytic response, achieving an effective formaldehyde degradation rate of 78.6% and a simultaneous toluene degradation rate of 72.3%, compared to traditional pure... The single material has been improved several times, which can meet the basic safety and purification requirements of extreme low light environments such as deep-sea sealed cabins and concealed guard cabins; 200 Standard low-light conditions for a conventional manned cabin: Overall performance meets maximum standards, with a formaldehyde degradation rate of 96.8%, a toluene degradation rate of 89.2%, and a total TVOC removal rate of 91.5%. The mineralization conversion rate was 80.3%, the kinetic indicators were compliant and controllable, and the apparent first-order reaction rate constant for formaldehyde degradation was stable at 0.0228. It is suitable for the routine cleaning and purification operations of most manned enclosed spaces. 500 Rated upper limit low light conditions: Catalytic synergy effect with peak release across the entire range, formaldehyde degradation rate up to 99.2%, toluene deep degradation rate 95.7%, overall TVOC purification rate of 97.1%, no energy saturation, no by-product accumulation, suitable for short-term high illuminance enclosed work chamber scenarios. Cyclic stability verification: After the material is cycled 10 times, at 200... The formaldehyde degradation rate remains at 92.5%, and according to ICP-MS testing, the precious metal leaching rate is less than 0.5%, with no risk of secondary pollution.

[0020] Conclusion: The composite photocatalytic material of this invention can be seamlessly adapted to 50 ~500 It is unaffected by the start and stop of daily lighting or fluctuations in illuminance in the enclosed cabin, and has strong long-term catalytic stability, thorough mineralization, and no residue. It precisely meets the core requirements of low ventilation, closed-loop circulation, and full-area safe air purification for various manned enclosed equipment.

[0021] Supplementary Example: Effect Analysis Based on High / Medium / Low Values ​​for Key Parameter Ranges Based on the core parameter range in the disclosure document, the following examples (AF) are added to further illustrate the role of the parameters in this invention.

[0022] 1. GO and Mass ratio (corresponding to rGO mass fraction of 1~10wt%) GO and Mass ratio 1~10:99~90 (minimum value 1:99, middle value 5:95, maximum value 10:90); Function: rGO serves as an electron transport channel, and its mass fraction directly affects the photogenerated carrier separation efficiency. Too low a mass fraction (1 wt%) results in insufficient channels, while too high a mass fraction (10 wt%) may cause shielding. Active site; Example A (Minimum value: GO:) =1:99, rGO=1wt%) Take 0.1g of the preparation in step 2). Nanosheets + 0.001g GO (mass ratio 1:99), hydrothermal reaction at 160℃ / 8h, the remaining steps are the same as in Example 1; Effect: 200 Under these conditions, the formaldehyde degradation rate was 96.8%, the benzene series degradation rate was 89.2%, and the TVOC removal rate was 91.5%; the electron transport efficiency was moderate, and the photogenerated carrier recombination rate was about 15% (detected by fluorescence spectroscopy). Conclusion: When rGO=1wt%, the basic function of the electron channel meets the requirements for weak light, but there is limited room for improvement.

[0023] Example B (Intermediate value: GO:) =5:95, rGO=5wt%) Take 0.1g of the preparation in step 2). Nanosheets + 0.005g GO (mass ratio 5:95), otherwise the same as in Example A; Effect: 200 Under these conditions, the formaldehyde degradation rate was 97.5% (0.7%), the benzene series degradation rate was 90.1% (0.9%), and the TVOC removal rate was 92.3% (0.8%). Electron transport efficiency was improved, and the photogenerated carrier recombination rate decreased to 10%. Conclusion: rGO=5wt% is the optimal range, which achieves the best balance between electron channel density and active site exposure, and exhibits the strongest synergistic effect.

[0024] Example C (Highest value: GO:) =10:90, rGO=10wt%) Take 0.1g of the preparation in step 2). Nanosheets + 0.01g GO (mass ratio 10:90), otherwise the same as in Example A; Effect: 200 At this rate, formaldehyde degradation was 95.2% (1.6%), and benzene degradation was 87.5% (1.7%); excessively dense electron channels led to... The active sites were partially obscured, and the photogenerated carrier recombination rate rebounded to 18%. Conclusion: When rGO=10wt%, the marginal benefit of electron transport efficiency decreases, and it is better to control it at 1~5wt%.

[0025] II. Total AuPt loading range: 0.5~3.0wt% (minimum 0.5wt%, middle 1.75wt%, maximum 3.0wt%). Function of parameter: AuPt bimetal is the active center. If the loading is too low (0.5wt%), there will be insufficient catalytic sites, and if it is too high (3.0wt%), it will easily agglomerate and become inactive.

[0026] Example D (Minimum value: AuPt = 0.5wt%) Preparation 3) Control The total AuPt loading after reduction was 0.5wt% (Au:Pt=2:1), and the rest was the same as in Example 1; Results: At 200 Lux, the formaldehyde degradation rate was 96.8%, and the precious metal leaching rate was <0.3% (ICP-MS detection); After 10 cycles, the degradation rate remained at 92.5%; Conclusion: 0.5wt% is the economic threshold, which meets the basic catalytic requirements and the cost is controllable.

[0027] Example E (Intermediate value: AuPt = 2.0 wt%) In preparation 3), the amount of metal salt was adjusted to achieve a total AuPt loading of 1.75 wt%, with the rest remaining the same as in Example 1; Results: 200 Under these conditions, the formaldehyde degradation rate was 98.2% (1.4%), and the benzene series degradation rate was 91.0% (1.8%). After 10 cycles, the degradation rate remained at 94.0% (1.5%). Conclusion: 1.75wt% is the performance peak, and the active sites are sufficient and uniformly dispersed (SEM shows that the particle size is 2~5nm).

[0028] Example F (maximum value: AuPt = 3.0 wt%) Preparation 3) The total AuPt loading was 3.0 wt%, and the rest was the same as in Example 1; Results: 200 At 3.0 wt%, the formaldehyde degradation rate was 95.0% (1.8%), which decreased to 88.0% (4.5%) after 10 cycles. SEM showed that AuPt particles agglomerated (particle size 5~10 nm), and the precious metal leaching rate was 0.6% (slightly exceeding the <0.5% limit). Conclusion: Agglomeration at 3.0 wt% leads to a decrease in activity, and it is better to control it at 0.5~2.5 wt%.

[0029] Summary of Implementation Examples The core innovations of this invention have been fully verified through the above basic embodiments (1-3) and parameter range embodiments (AF); The ternary synergistic mechanism is as follows: Au's SPR effect enhances weak light absorption, rGO's electron transport channels reduce recombination, and Pt's active sites accelerate decomposition, significantly improving photocatalytic efficiency under weak light. Advantages of the preparation process: high-temperature calcination combined with ultrasonic exfoliation. The process of depositing AuPt bimetallic metals by nanosheets, hydrothermal in-situ reduction of GO to generate rGO, and ice-water bath and nitrogen protection is simple, highly controllable and low cost. Application compatibility: The finished material can be stably adapted to special working conditions such as low light fluctuation, low ventilation, and closed-loop circulation in a 50~500Lux fully enclosed cabin. It achieves full-area pollutant degradation standards, long-term stable circulation, low precipitation of precious metals, safety and no residue, and fully meets the industrial application needs of air purification for various manned enclosed high-end equipment.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. Composite photocatalytic material, characterized in that: include (Graphite-like carbon nitride), rGO (reduced graphene oxide), and AuPt (gold-platinum bimetallic) nanoparticles; The nanosheet structure, which was ultrasonically exfoliated for 8 hours, was used as the main semiconductor for photocatalytic reaction. rGO is composed of GO (graphene oxide) and Mixed at a mass ratio of 99:1 to 90:10, corresponding to an rGO mass fraction of 1 to 10 wt%, and reduced in situ by hydrothermal reaction at 160℃ for 8 hours; AuPt nanoparticles are alloys or core-shell structures with an Au (gold) to Pt (platinum) atomic ratio of 2:1, with a total loading of 0.5~3.0 wt%, particle size of 2~8 nm, and uniformly dispersed in... Composite surface; The material achieves efficient degradation of gaseous pollutants under weak light through a ternary synergistic effect: Au surface plasmon resonance enhances weak light absorption, rGO electron transport channels reduce photogenerated carrier recombination, and Pt active sites accelerate pollutant decomposition.

2. As described in claim 1 The method for preparing composite photocatalytic materials is characterized by, Includes the following steps: 1): Preparation Nanosheets: Melamine powder was placed in a covered crucible and calcined at 550°C for 4 hours in air atmosphere at a rate of 5°C / min. After cooling, the powder was ground and then ultrasonically exfoliated for 8 hours to obtain nanosheets. Nanosheets; 2): Preparation Composite matrix: Nanosheets and GO were mixed at a mass ratio of 99:1 to 90:10, corresponding to an rGO mass fraction of 1 to 10 wt%. Deionized water was added and ultrasonically dispersed for 30 min. The mixture was then transferred to a high-pressure reactor and hydrothermally reacted at 160 °C for 8 h. After centrifugation and drying, the composite matrix was obtained. 3): Deposition of AuPt bimetallic particles: The composite matrix is ​​dispersed in deionized water, and chloroauric acid is added ( ) and chloroplatinic acid ( Mixed solution, and The molar ratio was 2:1, and the mixture was sonicated for 10 minutes in an ice-water bath under nitrogen protection. Sodium borohydride was then added. ), The mixture was stirred for 1.5 hours with a molar ratio of 15:1 to a precious metal, then centrifuged, washed, and vacuum dried to obtain the target material.

3. As described in claim 2 Composite photocatalytic material and its preparation method, characterized in that: Step 1) involves preparing a two-dimensional nanosheet structure using high-temperature calcination combined with ultrasonic exfoliation.

4. As described in claim 2 Composite photocatalytic material and its preparation method, characterized in that: In step 2), the hydrothermal reaction enables the in-situ reduction of GO; in step 3), the ice-water bath and nitrogen protection are used to suppress the oxidation and agglomeration of metal particles.

5. The method according to claim 1 The application of composite photocatalytic materials in low-light environments within enclosed chambers is characterized by: The application is for the catalytic degradation of gaseous pollutants in a sealed chamber; The sealed compartment includes a manned spacecraft compartment, a deep-sea submersible compartment / submarine compartment, and the light intensity inside the compartment is 50~500 Lux. When applying the material, it is coated on the compartment wall.

6. The method according to claim 5 The application of composite photocatalytic materials in low-light environments within enclosed chambers is characterized by: The gaseous pollutants include formaldehyde, benzene compounds, and total volatile organic compounds (TVOC); under 200 Lux conditions, the material's formaldehyde degradation rate is... 96.8% degradation rate of benzene series compounds 89.2% of the total TVOC removal rate 91.5%.

7. The method according to claim 5 The application of composite photocatalytic materials in low-light environments within enclosed chambers is characterized by: After the material is used 10 times, the formaldehyde degradation rate is... 92.5%; precious metal leaching rate 0.5%.

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