A method for preparing an integrated composite catalyst containing a titanium nitride photothermal layer by using light concentration

Abstract

The present invention discloses a method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using light concentration, belonging to the technical field of catalysts. The preparation method is as follows: using titanium foam metal as the substrate of the integral composite catalyst; growing a layer of titanium nitride in situ on the substrate as the photothermal layer by the method of light concentration and photothermal effect; growing a metal oxide precursor on the titanium nitride photothermal layer by the sol-gel method, and using a light concentration device to convert the precursor into a metal oxide photoelectric layer; finally, loading metal nanoparticles with a surface plasmon resonance effect on the surface of the metal oxide photoelectric layer by photodeposition to obtain an integral composite photocatalyst containing a titanium nitride photothermal layer. The present invention can generate a titanium nitride composite catalyst without external energy input and with a green and pollution-free preparation process. This method is easy to operate, has good repeatability, and the prepared integral composite catalyst has certain application prospects in the fields of photocatalysis, thermal catalysis, and light concentration and photothermal photocatalysis.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts and relates to a method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using a condenser. Background Art

[0002] With the continuous enrichment of the technical means for preparing catalysts, various preparation methods for titanium nitride (TiN) composite catalysts have emerged. Titanium nitride has good chemical stability, electrical conductivity, and surface plasmon resonance effect, and can be used as a new generation of photothermal conversion materials, showing great development prospects in the fields of photocatalysis, thermal catalysis, and photothermal catalysis.

[0003] However, traditional methods for preparing titanium nitride include the reduction of nitrogen method, sol-gel method, and molten salt method. The reduction of nitrogen method requires the use of NH3 gas with a strong pungent smell, which is not conducive to the green preparation of titanium nitride; the sol-gel method has a complex process and high preparation cost; the molten salt method has high external energy consumption and the molten salt has a certain corrosive loss to the equipment.

[0004] By using the condensing photothermal effect under a condensing system, high temperature can be formed on the surface of titanium foam metal. In an N2 atmosphere, titanium nitride can be formed on the surface of titanium foam metal, and titanium nitride can be used as a photothermal layer; similarly, by using the condensing photothermal effect, a metal oxide photoelectric layer can be formed on the surface of titanium nitride. This method for preparing a titanium nitride composite photothermal catalyst by using the condensing photothermal effect in a condensing system does not require external energy input and no polluting gases are generated during the whole process, which is green and safe, providing a new method and approach for the preparation of titanium nitride composite catalysts. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using a condenser. By using the condensing photothermal effect under a condensing system, titanium nitride is grown on the surface of a titanium foam metal substrate in a nitrogen atmosphere, and at the same time, a metal oxide photoelectric layer can also be grown by using the condensing photothermal effect to prepare a titanium nitride composite photothermal catalyst; by using this method, a titanium nitride composite catalyst can be generated without external energy input and with a green and pollution-free preparation process.

[0006] The technical problem of the present invention is: By using the condensing photothermal effect under a condensing system, a titanium nitride photothermal layer is grown on a titanium-based metal substrate in a nitrogen atmosphere, providing a new method for the preparation of titanium nitride composite catalysts, and the prepared integral composite catalyst has certain application prospects in the fields of photocatalysis, thermal catalysis, and condensing photothermal photocatalysis.

[0007] Technical solution: A method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using condensing light; using titanium foam metal as the substrate of the integral composite catalyst; growing a layer of titanium nitride in situ on the substrate as the photothermal layer by the method of condensing light and heat; growing a metal oxide precursor on the titanium nitride photothermal layer by the sol-gel method, and using a condensing device to convert the precursor into a metal oxide photoelectric layer; finally, loading metal nanoparticles with a surface plasmon resonance effect on the surface of the metal oxide photoelectric layer by photodeposition to obtain an integral composite photothermal catalyst containing a titanium nitride photothermal layer.

[0008] Further, the specific preparation steps are as follows:

[0009] Step (1): Select titanium foam metal as the substrate;

[0010] Step (2): Pretreat the titanium foam metal substrate, remove the surface oxide layer, place it in a condensing reaction device, introduce nitrogen into the device and maintain the pressure, use a Fresnel lens to focus the light in the entire solar band on the surface of the titanium foam substrate, control the light intensity and illumination time, and obtain a dense titanium nitride photothermal layer on the surface of the titanium foam substrate;

[0011] Step (3): Add a certain amount of metal oxide precursor solution to isopropanol solvent to prepare a precursor solution for use;

[0012] Mix the prepared acetic acid and 2,4-pentanedione in a certain ratio to make a chelating agent;

[0013] Add the prepared chelating agent to the precursor solution for use and stir it in a closed state; thus, a metal oxide thin film precursor solution is prepared;

[0014] Then immerse the titanium foam substrate with the grown titanium nitride photothermal layer in the metal oxide thin film precursor solution for a certain time and take it out evenly;

[0015] Step (4): Place the substrate flat, use a Fresnel lens to focus sunlight on the substrate, control the light intensity and illumination time, use the concentrated heat by condensing light to make the precursor film form a metal oxide film at high temperature; after the metal oxide film is completely formed, repeat the above operation multiple times to obtain metal oxide films with different thicknesses, and finally obtain a metal oxide film photoelectric layer on the titanium foam substrate;

[0016] Step (5): Mix a certain amount of deionized water and methanol, and add a certain concentration of noble metal ion solution to prepare a photodeposition precursor solution;

[0017] Place the titanium foam substrate carrying the metal oxide thin film photoelectric layer in the precursor solution, and use photodeposition to load noble metal nanoparticles on the surface of the catalyst, and finally make an integrated composite photothermal catalyst containing a titanium nitride photothermal layer.

[0018] Further, in step (1), the titanium foam metal is used as the substrate.

[0019] Further, in step (2), the light intensity is 2500 mW·cm -2 ~4000 mW·cm -2 , and the light irradiation duration is 30-60 min.

[0020] Further, in step (3), the metal oxide precursor solution selects aluminum isopropoxide and tetrabutyl titanate.

[0021] Further, in step (3), 0.5-1.0 mol of the metal oxide precursor solution is added to every 100 mL of isopropanol solvent.

[0022] Further, in step (3), the molar ratio of acetic acid to 2,4-pentanedione in the prepared chelating agent is 1:1 to 1:2. 2-4 mL of the chelating agent is added to every 100 mL of the precursor solution, and the stirring time is 20-60 min.

[0023] Further, in step (3), the standing time of the titanium foam metal substrate grown with the TiN photothermal layer in the precursor solution is 5-15 min.

[0024] Further, in step (4), the light intensity is 1500 mW·cm -2 ~3000 mW·cm -2 , and the light irradiation duration is 60-180 min.

[0025] Further, in step (5), the noble metal ion solution selects chloroauric acid solution, chloroplatinic acid solution, sodium chloropalladate solution and silver nitrate solution;

[0026] The concentration of the noble metal ion solution is 0.02-0.20 g·mL -1 .

[0027] Further, in step (5), the light intensity during the photodeposition process is 300 mW·cm -2 ~400 mW·cm -2 , and the light irradiation time is 10-30 min.

[0028] Further, the high temperature in the present invention is in the range of 300-400 °C.

[0029] Beneficial effects: Compared with the prior art, the present invention is characterized in that: the present invention provides a method for preparing a monolithic composite catalyst containing a titanium nitride photothermal layer by using concentrated light. The method is a new attempt, which can generate a titanium nitride composite catalyst without the need for external energy input and in a green and pollution-free preparation process. The method is easy to operate and has good repeatability. The prepared monolithic composite catalyst has certain application prospects in the fields of photocatalysis, thermal catalysis, concentrated light, thermal and photocatalytic catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a diagram of the light focusing system device in the present invention;

[0031] Figure 2 This is the X-ray diffraction pattern of the titanium nitride-based catalyst prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solution of the present invention, the technical solution of the present invention is further described in detail below with reference to the accompanying drawings;

[0033] The present invention discloses a method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using concentrated light;

[0034] A titanium nitride photothermal layer is grown on a titanium foam metal substrate by a concentrated photothermal method; a concentrating device is then used to convert the precursor into a metal oxide photoelectric layer; finally, metal nanoparticles with a plasma resonance effect are loaded on the surface of the photoelectric layer by light deposition, and an integral composite photothermal catalyst containing a titanium nitride photothermal layer is finally generated;

[0035] The specific preparation steps are as follows:

[0036] 1. Select titanium foam as the substrate;

[0037] 2. Pre-treat the titanium foam metal substrate, remove the surface oxide layer, place it in a focusing device, introduce nitrogen (N2) into the device to maintain a certain pressure, and use a Fresnel lens to focus the light of the entire solar band on the surface of the titanium foam substrate, control the light intensity and illumination time, and obtain a dense titanium nitride (TiN) photothermal layer on the surface of the titanium foam metal substrate;

[0038] 3. Add a certain amount of metal oxide precursor solution to isopropanol solvent, then mix acetic acid and 2-4-pentanedione in a certain proportion to prepare a chelating agent; add the chelating agent to the isopropanol solvent, stir in a closed container for a certain period of time, and prepare a metal oxide thin film precursor solution. Completely immerse the titanium foam metal substrate with the titanium nitride photothermal layer in the precursor solution for a certain period of time and then take it out at a uniform speed;

[0039] 4. Place the substrate flat, use a Fresnel lens to concentrate sunlight on the substrate, control the light intensity and illumination time, and use the concentrated light to concentrate heat, so that the precursor film forms a metal oxide film at high temperature. After the metal oxide film is completely formed, repeat the above operations multiple times to obtain metal oxide films with different thicknesses, and finally obtain the metal oxide film photoelectric layer on the titanium foam metal substrate;

[0040] 5. Mix a certain amount of deionized water and methanol, and add a certain concentration of precious metal ion solution to prepare a photodeposition precursor solution. Place the titanium foam metal substrate carrying the metal oxide film photoelectric layer in the precursor solution, and use the photodeposition method to load precious metal nanoparticles on the catalyst surface to make an integrated composite photothermal catalyst containing a titanium nitride photothermal layer.

[0041] The titanium foam metal substrate used in the present invention is titanium foam.

[0042] In the present invention, the pressure remains at 0.2 - 0.5 MPa after introducing nitrogen.

[0043] In the present invention, the light intensity for growing the titanium nitride photoelectric layer is 2500 mW·cm -2 ~4000 mW·cm -2 , and the illumination time is 30 - 60 min.

[0044] The metal oxide precursor solution used in the present invention is aluminum isopropoxide and tetrabutyl titanate.

[0045] In the present invention, 0.5 - 1.0 mol of the metal oxide precursor solution is added to every 100 mL of isopropanol solution.

[0046] In the present invention, the molar ratio of acetic acid to 2,4 - pentanedione in the chelating agent is 1:1 - 1:2. 2 - 4 mL of the chelating agent is added to every 100 mL of the precursor solution, and the stirring time is 20 - 60 min.

[0047] In the present invention, the standing time of the titanium foam metal substrate with a grown titanium nitride photothermal layer in the precursor solution is 5 - 15 min.

[0048] In the present invention, the light intensity for growing the metal oxide photoelectric layer is 1500 mW·cm -2 ~3000 mW·cm -2 , and the illumination time is 60 - 180 min.

[0049] In the present invention, the precious metal ion solution is selected from chloroauric acid solution, chloroplatinic acid solution, sodium chloropalladate solution and silver nitrate solution;

[0050] The concentration of the noble metal ion solution is 0.02 to 0.20 g·mL -1 .

[0051] In the present invention, the volume ratio of deionized water to methanol in the photodeposition precursor solution is 4:1 to 3:1. The volume of the noble metal ion solution added to every 100 mL of the photodeposition precursor solution is 100 to 300 μL.

[0052] In the present invention, the light intensity during the photodeposition process is 300 mW·cm -2 ~400mW·cm -2 , the illumination time is 10 to 30 minutes.

[0053] Embodiment 1:

[0054] The 10*10*2mm titanium foam substrate was pretreated. The surface oil was first removed with anhydrous ethanol, and then the surface oxide layer was removed with 0.1M dilute hydrochloric acid under ultrasound. After being washed with deionized water, it was dried under nitrogen for 6 hours for use. The pretreated titanium foam was placed in a focusing device, nitrogen was introduced, the pressure of the reaction system was maintained at 0.3MPa, and the light intensity of the xenon lamp was adjusted to 2500mW·cm -2 , using Fresnel lens to focus full-band sunlight on the surface of titanium foam, irradiating for 30 minutes, a dense titanium nitride photothermal layer is obtained on the surface of titanium foam substrate; adding 0.5 mol aluminum isopropoxide solution to 100 mL isopropanol solution, adding 2 mL acetic acid and chelating agent made of 2-4-pentanedione, the molar ratio of acetic acid to 2-4-pentanedione is 1:1, and stirring for 20 minutes to obtain aluminum oxide film precursor solution; the titanium foam with titanium nitride photothermal layer is completely immersed in the aluminum oxide film precursor solution for 5 minutes and then taken out at a uniform speed; the substrate carrying the aluminum oxide film precursor is placed flat, and the simulated sunlight is focused on the substrate using Fresnel lens, and the xenon lamp intensity is 1500 mW cm -2 , the illumination time is 60min, after the aluminum oxide film is completely formed, the operation is repeated 3 times to obtain the aluminum oxide film photoelectric layer on the titanium foam substrate; 80mL of deionized water and 20mL of methanol are mixed evenly, and 200μL of 0.02g·mL -1 The titanium foam substrate with the aluminum oxide thin film photoelectric layer was placed in the solution for photodeposition. The light intensity of the photodeposition was 300 mW cm -2 , photodeposition for 15 minutes to obtain an integral composite foam titanium-based photothermal catalyst containing a titanium nitride photothermal layer.

[0055] Embodiment 2:

[0056] The 20*20*3 mm titanium foam substrate was pretreated. First, the surface oil stain was removed with anhydrous ethanol, then the surface oxide layer was removed with 0.1 M dilute hydrochloric acid under ultrasonic treatment. After washing with deionized water, it was dried under nitrogen for 6 h and reserved. The pretreated titanium foam was placed in a light-concentrating device, nitrogen was introduced, and the pressure of the reaction system was maintained at 0.5 MPa. The light intensity of the xenon lamp was adjusted to 4000 mW·cm -2 , and the sunlight in the full wavelength band was concentrated on the surface of the titanium foam by using a Fresnel lens. After 30 min of light irradiation, a dense titanium nitride photothermal layer was obtained on the surface of the titanium foam substrate. 1.0 mol of tetrabutyl titanate solution was added to 100 mL of isopropanol solution, and a chelating agent made of 2 mL of acetic acid and 2-4 pentanedione was added. The molar ratio of acetic acid to 2-4 pentanedione was 1:1. After sealing and stirring for 30 min, a titanium dioxide thin film precursor solution was obtained. The titanium foam with the titanium nitride photothermal layer grown on it was completely immersed in the titanium dioxide thin film precursor solution for 5 min and then taken out at a constant speed. The substrate carrying the titanium dioxide thin film precursor was placed flat, and the simulated sunlight was concentrated on the substrate by using a Fresnel lens. The xenon lamp intensity was 2000 mW·cm -2 , and the light irradiation time was 100 min. After the titanium dioxide thin film was completely formed, the operation was repeated 5 times to obtain a titanium dioxide thin film optoelectronic layer on the titanium foam substrate. 80 mL of deionized water and 20 mL of methanol were mixed evenly, and 250 μL of chloroauric acid solution with a concentration of 0.10 g·mL -1 was added. The titanium foam substrate carrying the titanium dioxide thin film optoelectronic layer was placed in the solution for photodeposition. The light intensity of the photodeposition was 320 mW·cm -2 , and the photodeposition was carried out for 20 min to obtain an integrated composite titanium foam substrate photocatalyst containing a titanium nitride photothermal layer.

[0057] Example 3:

[0058] The 10*10*5 mm titanium foam substrate was pretreated. First, the surface oil stain was removed with anhydrous ethanol, then the surface oxide layer was removed with 0.1 M dilute hydrochloric acid under ultrasonic treatment. After washing with deionized water, it was dried under nitrogen for 6 h and reserved. The pretreated titanium foam was placed in a light-concentrating device, nitrogen was introduced, and the pressure of the reaction system was maintained at 0.5 MPa. The light intensity of the xenon lamp was adjusted to 4000 mW·cm -2, a Fresnel lens was used to focus sunlight of the entire wavelength on the surface of the titanium foam, and the illumination was performed for 60 minutes to obtain a dense titanium nitride photothermal layer on the surface of the titanium foam substrate; 1.0 mol of aluminum isopropoxide solution was added to 100 mL of isopropanol solution, and 4 mL of a chelating agent made of acetic acid and 2-4-pentanedione was added, and the molar ratio of acetic acid to 2-4-pentanedione was 1:2. After being stirred in a closed environment for 60 minutes, an aluminum oxide film precursor solution was obtained; the titanium foam with the titanium nitride photothermal layer grown was completely immersed in the aluminum oxide film precursor solution for 10 minutes and then taken out at a uniform speed; the substrate carrying the aluminum oxide film precursor was placed flat, and the simulated sunlight was focused on the substrate using a Fresnel lens, and the xenon lamp intensity was 3000 mW·cm -2 , the illumination time is 150min, after the aluminum oxide film is completely formed, the operation is repeated 7 times to obtain the aluminum oxide film photoelectric layer on the titanium foam substrate; 75mL of deionized water and 25mL of methanol are mixed evenly, and 100μL of 0.20g·mL -1 The titanium foam substrate with the aluminum oxide thin film photoelectric layer was placed in the solution for photodeposition. The light intensity of the photodeposition was 400 mW cm -2 , photodeposition for 30 minutes to obtain an integral composite foam titanium-based photothermal catalyst containing a titanium nitride photothermal layer.

[0059] Embodiment 4:

[0060] The 20*10*2.5mm titanium foam substrate was pretreated. The surface oil was first removed with anhydrous ethanol, and then the surface oxide layer was removed with 0.1M dilute hydrochloric acid under ultrasound. After being washed with deionized water, it was dried under nitrogen for 6 hours for use. The pretreated titanium foam substrate was placed in a focusing device, nitrogen was introduced, the pressure of the reaction system was maintained at 0.2MPa, and the light intensity of the xenon lamp was adjusted to 3300mW·cm -2 , using Fresnel lens to focus full-band sunlight on the surface of titanium foam substrate, irradiating for 40 minutes, a dense titanium nitride photothermal layer is obtained on the surface of titanium foam substrate; adding 0.8 mol tetrabutyl titanate solution to 100 mL isopropanol solution, adding 4 mL chelating agent made of acetic acid and 2-4-pentanedione, the molar ratio of acetic acid to 2-4-pentanedione is 2:3, and stirring for 30 minutes to obtain titanium dioxide film precursor solution; the titanium foam substrate with titanium nitride photothermal layer is completely immersed in the titanium dioxide film precursor solution for 5 minutes and then taken out at a uniform speed; the substrate carrying titanium dioxide film precursor is placed flat, and the simulated sunlight is focused on the substrate using Fresnel lens, and the xenon lamp intensity is 2000 mW·cm -2, the light irradiation time was 60 min. After the titanium dioxide thin film was completely formed, the operation was repeated 15 times to obtain a titanium dioxide thin film optoelectronic layer on the titanium foam substrate; 75 mL of deionized water and 25 mL of methanol were mixed evenly, and 300 μL of sodium palladium chloride solution with a concentration of 0.15 g·mL -1 was added. The titanium foam substrate carrying the titanium dioxide thin film optoelectronic layer was placed in the solution for photodeposition. The light intensity of photodeposition was 300 mW·cm -2 . After 10 min of photodeposition, an integrated composite titanium foam substrate photocatalyst containing a titanium nitride photothermal layer was obtained.

[0061] It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using light concentration, characterized in that, The specific preparation steps are as follows: Step (1): Select titanium foam metal as the substrate; Step (2): Pretreat the titanium foam metal substrate. After removing the surface oxide layer, place it in a concentrating reaction device. Introduce nitrogen gas into the device and maintain the pressure. Use a Fresnel lens to concentrate the light in the entire solar band on the surface of the titanium foam substrate. Control the light intensity and illumination time to obtain a dense titanium nitride photothermal layer on the surface of the titanium foam substrate; The light intensity is 2500 mW·cm -2 ~4000 mW·cm -2 , and the duration of light irradiation is 30 - 60 min; Step (3): Add a certain amount of metal oxide precursor solution to isopropanol solvent to prepare a precursor solution for use; Mix the prepared acetic acid and 2,4-pentanedione in a certain ratio to make a chelating agent; Add the prepared chelating agent to the precursor solution for use and perform sealed stirring; thus, a metal oxide thin film precursor solution is prepared; Then immerse the titanium foam substrate with the titanium nitride photothermal layer in the metal oxide thin film precursor solution for a certain time and take it out uniformly at a constant speed; Among them, the metal oxide precursor solution is one of aluminum isopropoxide and tetrabutyl titanate; Step (4): Place the substrate flat. Use a Fresnel lens to concentrate sunlight on the substrate. Control the light intensity and illumination time. Use the concentrated light to concentrate heat so that the precursor film forms a metal oxide film at high temperature; after the metal oxide film is completely formed, repeat the above operation multiple times to obtain metal oxide films with different thicknesses, and finally obtain a metal oxide film optoelectronic layer on the titanium foam substrate; The light intensity is 1500 mW·cm -2 ~3000 mW·cm -2 , and the duration of the light illumination is 60~180 min; Step (5): Mix a certain amount of deionized water and methanol and add a certain concentration of precious metal ion solution to prepare a photodeposition precursor solution; Place the titanium foam substrate carrying the metal oxide film optoelectronic layer in the precursor solution and use the photodeposition method to load precious metal nanoparticles on the catalyst surface, and finally make an integrated composite photothermal catalyst containing a titanium nitride photothermal layer; The light intensity during the photodeposition process is 300 mW·cm -2 ~400 mW·cm -2 , and the illumination time is 10 - 30 min.

2. The method for preparing an integrated composite catalyst containing a titanium nitride photothermal layer by using light concentration according to claim 1, wherein, In step (3), 0.5 - 1.0 mol of the metal oxide precursor solution is added to every 100 mL of isopropanol solvent.

3. A method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using light concentration according to claim 1, characterized in that, In step (3), the molar ratio of acetic acid to 2,4-pentanedione in the prepared chelating agent is 1:1 - 1:2; 2 - 4 mL of the chelating agent is added to every 100 mL of the precursor solution, and the stirring time is 20 - 60 min.

4. A method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using light concentration according to claim 1, characterized in that, In step (3), the standing time of the titanium foam metal substrate with the TiN photothermal layer in the precursor solution is 5 - 15 min.

5. A method for preparing an integral composite catalyst containing a titanium nitride photothermal layer by using light concentration according to claim 1, characterized in that, In step (5), the added precious metal ion solution is selected from one of chloroauric acid solution, chloroplatinic acid solution, sodium chloropalladate solution, and silver nitrate solution; The concentration of the precious metal ion solution is 0.02~0.20 g·mL -1 .

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