An atomically dispersed cerium supported photocatalyst and a photocatalyst odor-eliminating spray, and a preparation method and application thereof

Abstract

The present application belongs to the technical field of photocatalyst, and discloses a cerium-loaded photocatalyst with atomic-scale dispersion, a deodorant spray using the photocatalyst, and a preparation method and application thereof. A nitrogen-containing precursor is ground and calcined to obtain graphite-like carbon nitride, which is then subjected to nitration treatment, and then subjected to hydrothermal reaction with cerium salt and a solvent. In the catalyst, cerium is stably loaded on the surface of the nitrated graphite-like carbon nitride in the form of single atoms or small clusters, and the dispersion degree of cerium is high, which significantly improves the reaction activity and service life of the catalyst. The catalyst has strong response capability in the visible light range, and is suitable for use under indoor natural conditions without additional energy consumption. The spray prepared from the catalyst has simple formula, is safe and low-toxic, is convenient to use, does not damage the performance of leather, and is suitable for industrial application and promotion.

Description

Technical Field

[0001] This invention relates to the field of photocatalyst technology, and in particular to an atomically dispersed cerium-supported photocatalytic catalyst and a photocatalytic odor-removing spray, as well as their preparation methods and applications. Background Technology

[0002] With the widespread application of artificial leather in automobiles, furniture, and clothing, the large amounts of chemical additives, solvents, and resins used in its production often result in volatile organic compounds (VOCs) residues in the products, producing pungent odors and posing potential risks to human health and the environment. Traditional odor removal technologies mainly rely on masking, adsorption, or heat treatment, which suffer from problems such as short-lasting effects, high processing temperatures, or secondary pollution. Photocatalytic odor removal methods utilize light to excite photocatalysts, generating reactive oxygen species (ROS) that decompose odor molecules, especially singlet oxygen (ROS) with highly selective oxidation capabilities. 1 O2) can completely degrade odor molecules in artificial leather under mild environmental conditions without damaging the structure and color of the leather substrate.

[0003] Cerium (Ce), as a rare earth element, can significantly enhance the electron transfer and reactive oxygen species (ROS) generation capabilities of photocatalysts due to its unique redox properties and oxygen vacancy structure. However, most cerium-based materials currently exhibit unstable loading morphologies or low dispersion, limiting their photocatalytic efficiency. Therefore, this study aims to develop atomically dispersed cerium-supported photocatalysts that selectively generate... 1 O2 plays an important role in removing odor molecules. Summary of the Invention

[0004] The purpose of this invention is to provide an atomically dispersed cerium-supported photocatalytic catalyst and a photocatalytic deodorizing spray, as well as their preparation methods and applications, to solve the problems of unstable loading morphology or low dispersion of cerium-based materials and low photocatalytic efficiency in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing an atomically dispersed cerium-supported photocatalytic catalyst, comprising the following steps:

[0007] The nitrogen-containing precursor was ground and then calcined to obtain graphite-like carbon nitride.

[0008] Graphite-like carbon nitride was impregnated in nitric acid solution and subjected to nitration to obtain nitrated graphite-like carbon nitride.

[0009] Nitrated graphitic carbon nitride, cerium salt, and solvent were mixed and subjected to a hydrothermal reaction to obtain atomically dispersed cerium-supported photocatalyst catalysts.

[0010] The mass ratio of the cerium salt to the nitrated graphitic carbon nitride is 1~5:100.

[0011] Preferably, the nitrogen-containing precursor is one or more of melamine, urea, ammonium bicarbonate, thiourea, and cyanuric acid; the calcination temperature is 450~700℃; and the calcination time is 1~5h.

[0012] Preferably, the mass concentration of the nitric acid solution is 68%; the nitration temperature is 180°C; and the nitration time is 4 hours.

[0013] Preferably, the solvent is water and / or anhydrous ethanol; the temperature of the hydrothermal reaction is 120~220℃; and the time of the hydrothermal reaction is 2~10h.

[0014] The present invention also provides a method for preparing an atomically dispersed cerium-supported photocatalyst catalyst.

[0015] This invention also provides the application of an atomically dispersed cerium-supported photocatalytic catalyst in the preparation of a photocatalytic deodorizing spray.

[0016] The present invention also provides a photocatalytic deodorizing spray, comprising the above-mentioned atomically dispersed cerium-supported photocatalytic catalyst and an ethanol solution.

[0017] Preferably, the ratio of the atomically dispersed cerium-supported photocatalyst catalyst to the ethanol solution is 1~10 mg: 100 mL.

[0018] This invention also provides a method for preparing a photocatalytic odor-removing spray, comprising the following steps:

[0019] A photocatalyst supported on cerium and dispersed at the atomic scale is mixed with an ethanol solution to obtain a photocatalyst deodorizing spray.

[0020] This invention also provides an application of a photocatalytic odor-removing spray in deodorizing artificial leather.

[0021] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) In the catalyst of the present invention, cerium is stably supported on the surface of nitrated graphitic carbon nitride in the form of single atoms or small clusters. The high dispersion of cerium significantly improves the reaction activity and service life of the catalyst.

[0023] 2) The catalyst of this invention has a strong response capability in the visible light range, is suitable for use under natural indoor conditions, and requires no additional energy consumption;

[0024] 3) The spray formulation prepared by the catalyst of the present invention is simple, safe, low in toxicity, easy to use, does not damage the performance of leather, and is suitable for industrial application and promotion. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0026] Figure 1 XRD patterns of PCN-Ce in Example 1 and PCN in Comparative Example 1;

[0027] Figure 2 XPS plots of PCN-Ce in Example 1 and PCN in Comparative Example 1;

[0028] Figure 3 The images shown are PCN-Ce dark field STEM images and element mapping images from Example 1; where (a) is the dark field STEM image, (b) is the Ce element mapping image, (c) is the C element mapping image, and (d) is the N element mapping image.

[0029] Figure 4 The UV-Vis absorption spectra of PCN-Ce in Example 1 and PCN in Comparative Example 1 are shown.

[0030] Figure 5 The image shows the electron paramagnetic resonance (EPR) pattern of PCN-Ce in Example 1. Detailed Implementation

[0031] This invention provides a method for preparing an atomically dispersed cerium-supported photocatalytic catalyst, comprising the following steps:

[0032] The nitrogen-containing precursor was ground and then calcined to obtain graphite-like carbon nitride, denoted as PCN.

[0033] PCN is impregnated in nitric acid solution to undergo nitration treatment, resulting in nitrated PCN.

[0034] Nitrated PCN, cerium salt, and solvent are mixed and subjected to a hydrothermal reaction to obtain an atomically dispersed cerium-supported photocatalyst catalyst.

[0035] In this invention, the nitrogen-containing precursor is preferably one or more of melamine, urea, ammonium bicarbonate, thiourea, and cyanuric acid, more preferably melamine or urea, and even more preferably melamine.

[0036] In this invention, the calcination temperature is preferably 450~700℃, more preferably 500~600℃, and even more preferably 550℃; the calcination time is preferably 1~5h, more preferably 3~5h, and even more preferably 4h.

[0037] In this invention, the preferred mass concentration of the nitric acid solution is 68%; the preferred temperature for the nitration treatment is 180°C; and the preferred time for the nitration treatment is 4 hours. The PCN of this invention, after nitration treatment, possesses abundant N coordination sites and a two-dimensional lamellar structure, which is beneficial for the stable anchoring of single-atom cerium. Furthermore, compared to traditional PCN, it has greater bulkiness, making cerium ions easier to disperse, which also facilitates the formation of single atoms and clusters.

[0038] In this invention, the mass ratio of the cerium salt to the nitrated PCN is preferably 1~5:100, more preferably 2~5:100, and even more preferably 2.5:100. Traditional cerium-supported catalysts typically form CeO2 due to the large proportion of cerium salt precursors. In this invention, the mass ratio of the added cerium salt to the nitrated PCN is less than or equal to 5%. At such a low ratio, single atoms and clusters will form; increasing the amount of cerium salt would result in the formation of a large amount of CeO2.

[0039] In this invention, the cerium salt is preferably cerium nitrate hexahydrate (Ce(NO3)3·6H2O).

[0040] In this invention, the solvent is preferably water and / or anhydrous ethanol, more preferably water or anhydrous ethanol, and even more preferably water.

[0041] In this invention, the preferred method for mixing the nitrated PCN, cerium salt, and solvent is ultrasound. This invention uses ultrasound treatment to uniformly disperse and adsorb cerium ions onto the surface of the nitrated PCN.

[0042] In this invention, the temperature of the hydrothermal reaction is preferably 120~220℃, more preferably 160~200℃, and even more preferably 180℃; the time of the hydrothermal reaction is preferably 2~10h, more preferably 4~8h, and even more preferably 6h.

[0043] The present invention also provides a method for preparing an atomically dispersed cerium-supported photocatalyst catalyst.

[0044] This invention also provides the application of an atomically dispersed cerium-supported photocatalytic catalyst in the preparation of a photocatalytic deodorizing spray.

[0045] The present invention also provides a photocatalytic deodorizing spray, comprising the above-mentioned atomically dispersed cerium-supported photocatalytic catalyst and an ethanol solution.

[0046] In this invention, the preferred ratio of the atomically dispersed cerium-supported photocatalyst catalyst to the ethanol solution is 1-10 mg:100 mL, more preferably 3-8 mg:100 mL, and even more preferably 6 mg:100 mL.

[0047] In this invention, the ethanol solution is preferably a mixture of water and anhydrous ethanol; the volume ratio of water to anhydrous ethanol is preferably 1~9:1~9, more preferably 1~5:2~6, and even more preferably 1:4.

[0048] This invention also provides a method for preparing a photocatalytic odor-removing spray, comprising the following steps:

[0049] A photocatalyst supported on cerium and dispersed at the atomic scale is mixed with an ethanol solution to obtain a photocatalyst deodorizing spray.

[0050] This invention also provides an application of a photocatalytic odor-removing spray in deodorizing artificial leather.

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0052] Example 1

[0053] This embodiment provides a method for preparing an atomically dispersed cerium-supported photocatalyst catalyst, comprising the following steps:

[0054] 1) Weigh melamine powder, grind it evenly, and place it in a muffle furnace. Calcinate it at 550°C for 4 hours in air atmosphere. After cooling, obtain light yellow graphite-like carbon nitride powder (PCN). Then carry out nitration treatment by immersing PCN in 68% nitric acid solution at 180°C for 4 hours. After washing and drying, obtain nitrated PCN.

[0055] 2) Weigh 5 mg of cerium nitrate hexahydrate and dissolve it in 40 mL of deionized water. Add 200 mg of nitrated PCN and sonicate for 30 min to obtain a mixed solution.

[0056] 3) The mixture was transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to hydrothermal reaction at 180 °C for 6 h. After the reaction was completed, it was cooled to room temperature, washed repeatedly with deionized water and ethanol, and finally freeze-dried at -20 °C for 6 h to obtain atomically dispersed cerium-supported photocatalyst catalyst (PCN-Ce).

[0057] Example 2

[0058] This embodiment provides a method for preparing an atomically dispersed cerium-supported photocatalyst catalyst, comprising the following steps:

[0059] 1) For details on the preparation of nitrated PCN, please refer to Example 1;

[0060] 2) Weigh 10 mg of cerium nitrate hexahydrate and dissolve it in 40 mL of anhydrous ethanol / water (volume ratio 1:1), add 200 mg of nitrated PCN, and sonicate for 30 min to obtain the mixture;

[0061] 3) The mixture was transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to hydrothermal reaction at 160 °C for 4 h. After the reaction was completed, it was cooled to room temperature, washed repeatedly with deionized water and ethanol, and finally freeze-dried at -20 °C for 6 h to obtain atomically dispersed cerium-supported photocatalyst catalyst (PCN-Ce).

[0062] Example 3

[0063] This embodiment provides a method for preparing an atomically dispersed cerium-supported photocatalyst catalyst, comprising the following steps:

[0064] 1) For details on the preparation of nitrated PCN, please refer to Example 1;

[0065] 2) Weigh 10 mg of cerium nitrate hexahydrate and dissolve it in 40 mL of anhydrous ethanol / water (volume ratio 3:1), add 200 mg of nitrated PCN, and sonicate for 30 min to obtain the mixture;

[0066] 3) The mixture was transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and subjected to hydrothermal reaction at 180 °C for 8 h. After the reaction was completed, it was cooled to room temperature, washed repeatedly with deionized water and ethanol, and finally freeze-dried at -20 °C for 6 h to obtain atomically dispersed cerium-supported photocatalyst catalyst (PCN-Ce).

[0067] Comparative Example 1

[0068] This comparative example provides a method for preparing a photocatalyst catalyst, specifically as described in Example 1. The difference is that steps 2) and 3) are not performed, that is, the nitrated PCN prepared in step 1) is the photocatalyst catalyst (denoted as PCN).

[0069] Comparative Example 2

[0070] This comparative example provides a method for preparing a photocatalyst catalyst, specifically referring to Example 1. The difference is that in step 3), a hydrothermal reaction is not performed. The mixture is stirred at room temperature for 6 hours, then repeatedly washed with deionized water and ethanol, and finally freeze-dried at -20°C for 6 hours.

[0071] The XRD and XPS plots of PCN-Ce in Example 1 and PCN in Comparative Example 1 are shown below. Figure 1 and Figure 2 As shown. By Figure 1 As can be seen in the figure, both PCN and PCN-Ce samples show typical g-C3N4 characteristic diffraction peaks (approximately 27.6°), and no CeO2 characteristic peaks are observed. Figure 2 The absence of a distinct cerium peak indicates that cerium exists in amorphous or highly dispersed single-atom or cluster-supported forms, with clusters and single atoms exhibiting better catalytic activity.

[0072] The PCN-Ce dark-field STEM image and elemental mapping results of Example 1 are as follows: Figure 3 As shown, where, Figure 3 In the middle (a), the dark field image is shown, and (b) to (d) are the elemental mapping diagrams of Ce, C, and N. The diagrams show that Ce is uniformly distributed on the surface of PCN sheets, which further confirms the high dispersion of cerium on nitrated PCN, and that it exists in the form of clusters and single atoms (<10 nm).

[0073] The UV-Vis absorption spectra of PCN-Ce in Example 1 and PCN in Comparative Example 1 are shown below. Figure 4 As shown, by Figure 4 It can be seen that PCN-Ce exhibits a red shift in absorption edge and enhanced absorption intensity compared to PCN, indicating that the introduction of Ce leads to band gap contraction, enhances the visible light response range, and is beneficial for photocatalytic activity under indoor lighting conditions.

[0074] The electron paramagnetic resonance (EPR) spectrum of PCN-Ce in Example 1 is as follows: Figure 5 As shown, by Figure 5 It can be seen that under illumination, the PCN-Ce sample exhibits a significant enhancement of the g=2.003 radical signal, indicating that singlet oxygen was generated under illumination. 1 O2), while PCN showed no obvious signal. This indicates that the introduction of Ce definitely produced... 1 O2, thereby improving catalytic activity.

[0075] Application Example 1

[0076] This application example provides a method for preparing a photocatalytic odor-removing spray, including the following steps:

[0077] 30 mg of PCN-Ce from Example 1 was dispersed in 500 mL of a mixed solution of anhydrous ethanol and deionized water in a volume ratio of 4:1, and sonicated for 10 min to obtain a photocatalytic odor-removing spray for deodorizing artificial leather.

[0078] Application Example 2

[0079] This application example provides a method for preparing a photocatalytic odor-removing spray, including the following steps:

[0080] 20 mg of PCN-Ce from Example 2 was dispersed in a 1:1 mixture of 500 mL of anhydrous ethanol and deionized water and sonicated for 10 min to obtain a photocatalytic odor-removing spray for deodorizing artificial leather.

[0081] Application Example 3

[0082] This application example provides a method for preparing a photocatalytic odor-removing spray, including the following steps:

[0083] 30 mg of PCN-Ce from Example 3 was dispersed in a mixed solution of 500 mL of anhydrous ethanol and deionized water in a volume ratio of 3:1, and sonicated for 10 min to obtain a photocatalytic odor-removing spray for deodorizing artificial leather.

[0084] Comparative Application Example 1

[0085] This comparative application example provides a method for preparing a photocatalytic odor-removing spray, including the following steps:

[0086] 200 mg of PCN (Comparative Example 1) was dispersed in 500 mL of a mixed solution of anhydrous ethanol and deionized water in a volume ratio of 4:1, and sonicated for 10 min to obtain a photocatalytic odor-removing spray for deodorizing artificial leather.

[0087] Comparative Application Example 2

[0088] This comparative application example provides a method for preparing a photocatalytic odor-removing spray, including the following steps:

[0089] 30 mg of the photocatalyst catalyst from Comparative Example 2 was dispersed in a mixed solution of 500 mL of anhydrous ethanol and deionized water in a volume ratio of 4:1, and sonicated for 10 min to obtain a photocatalytic odor-removing spray for use in removing odors from artificial leather.

[0090] To evaluate the actual odor removal effect of the photocatalytic odor-removing spray of this invention, an odor level test experiment was conducted on artificial leather. The test adopted the national / industry standard material odor assessment method, the "nasal inhalation method," with at least three evaluators independently scoring the odor. If the scores from any two evaluators differed by more than two levels in a single test, a retest with up to five evaluators was required. If there was ambiguity in the odor level judgment, an intermediate score (e.g., 3.5) could be used for quantification, and the final result was the arithmetic mean of the scores. The odor level criteria are as follows:

[0091] Level 1: Odorless; Level 2: Odor present, but without interfering odor; Level 3: Odor present, but without interfering odor; Level 4: Interfering odor present; Level 5: Strongly interfering odor present; Level 6: Unbearable odor present.

[0092] The material used in the experiment was 14cm×14cm microfiber polyurethane suede (provided by Zhejiang Meisheng New Material Co., Ltd.), which was placed in a 1L sealed glass bottle to simulate the odor release experiment in the car interior environment.

[0093] Experiment 1 (Blank control group, no coating, no light exposure): Untreated microfiber polyurethane suede samples were placed in sealed glass bottles and heated at 80℃ for 2 hours to simulate high-temperature VOC release. After cooling to 60℃, the bottle cap was immediately opened, and three evaluators assessed the odor level using the "smell test," with scores of 6, 4, and 5, averaging 5.

[0094] Experiment 2 (Spraying and comparing the photocatalytic odor-removing spray from Example 1, followed by light irradiation): After aging the sample for 2 hours as described above, it was further irradiated under a 300W xenon lamp for 1 hour (wavelength range 350~780nm). After irradiation, the sample was cooled to 60℃ and then evaluated by three evaluators. The scoring results were level 5, level 4, and level 5, with an average of level 4.7.

[0095] Experiment 3 (Application of Photocatalytic Odor Eliminating Spray from Example 1): The photocatalytic odor eliminating spray was sprayed onto the surface of a microfiber polyurethane suede sample, applied 10 times, with a total spray volume of 5 mL, ensuring the surface was fully wetted. After heating the sample under the same conditions for 2 hours and then irradiating it with light for 1 hour, the odor level was assessed. The scores were 2.5, 2.5, and 3.0, with an average of 2.7.

[0096] The results of Experiments 1 through 3 are shown in Table 1. Table 1 shows that nitrated PCN can partially promote the degradation of odor substances, but the effect is limited. Compared with the control group, the spray prepared from the atomically dispersed cerium-supported photocatalyst catalyst of this invention significantly reduced the odor of artificial leather.

[0097] Table 1. Odor Removal Effect of Photocatalytic Odor Removal Spray

[0098]

[0099] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of preparing an atomically dispersed cerium supported photocatalyst, characterized by, The method comprises the following steps: grinding and calcining a nitrogen-containing precursor to obtain a graphite-like phase carbon nitride; immersing the graphite-like phase carbon nitride in a nitric acid solution to perform nitration treatment to obtain a nitrated graphite-like phase carbon nitride; mixing the nitrated graphite-like phase carbon nitride, a cerium salt and a solvent to perform a hydrothermal reaction to obtain an atomically dispersed cerium-loaded photocatalyst; the mass ratio of the cerium salt to the nitrated graphite-like phase carbon nitride is 1-5:

100.

2. The method for preparing an atomically dispersed cerium-supported photocatalyst catalyst according to claim 1, characterized in that, The nitrogen-containing precursor is one or more of melamine, urea, ammonium bicarbonate, thiourea and cyanuric acid; the calcination temperature is 450-700 DEG C; and the calcination time is 1-5 h.

3. The method for preparing an atomically dispersed cerium-supported photocatalyst catalyst according to claim 2, characterized in that, The mass concentration of the nitric acid solution is 68%; the nitration treatment temperature is 180 DEG C; and the nitration treatment time is 4 h.

4. The method of claim 1 or 2, wherein the method is characterized by, The solvent is water and / or anhydrous ethanol; the hydrothermal reaction temperature is 120-220 DEG C; and the hydrothermal reaction time is 2-10 h.

5. An atomically dispersed cerium-loaded photocatalyst prepared by the method of any one of claims 1-4.

6. The use of the atomically dispersed cerium-loaded photocatalyst of claim 5 in the preparation of a photocatalyst odor-removing spray.

7. An odor-eliminating photocatalyst spray, characterized by comprising: The photocatalyst odor-removing spray comprises the atomically dispersed cerium-loaded photocatalyst of claim 5 and an ethanol solution.

8. The photocatalyst deodorizing spray according to claim 7, wherein The ratio of the atomically dispersed cerium-loaded photocatalyst to the ethanol solution is 1-10 mg:100 mL.

9. A method for preparing a photocatalytic odor-removing spray according to claim 7 or 8, characterized in that, The method comprises the following steps: mixing the atomically dispersed cerium-loaded photocatalyst and the ethanol solution to obtain a photocatalyst odor-removing spray.

10. The use of the photocatalyst odor-removing spray of claim 7 or 8 in the removal of odors from artificial leather.

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