阅读说明：本技术 盐酸处理的Nb-Mo共掺杂g-C3N4光催化材料及其制备方法和应用 (Hydrochloric acid treated Nb-Mo co-doped g-C3N4Photocatalytic material and preparation method and application thereof ) 是由 李一杰 邢飞飞 陶然 范晓星 韩宇 张明怡 于 2021-09-01 设计创作，主要内容包括：本发明公开了盐酸处理的Nb-Mo共掺杂g-C-(3)N-(4)光催化材料及其制备方法和应用。将铌氧化物和钼氧化物粉末加入蒸馏水中,随后加入三聚氰胺,于80℃下磁力搅拌后,超声处理,得混合液；向所得混合液中逐滴滴入盐酸溶液,磁力搅拌均匀后,烘干,得前驱体；将前驱体研磨,在氮气气氛下高温煅烧,得目标产物Nb-Mo/g-C-(3)N-(4)光催化材料。利用本发明的方法制备的盐酸处理的Nb-Mo离子共掺杂g-C-(3)N-(4)光催化材料,改善了g-C-(3)N-(4)在可见光下对自然光响应低的缺陷,降低了电子空穴对复合率,提高了光降解速率,有效的提高了光催化活性,该方法成本低、易操作,在自然光下,利用自然光照可降解有机污染物。(The invention discloses Nb-Mo codoped g-C treated by hydrochloric acid 3 N 4 A photocatalytic material and a preparation method and application thereof. Adding niobium oxide and molybdenum oxide powder into distilled water, then adding melamine, magnetically stirring at 80 ℃, and performing ultrasonic treatment to obtain a mixed solution; dropwise adding a hydrochloric acid solution into the obtained mixed solution, uniformly stirring by magnetic force, and drying to obtain a precursor; grinding the precursor, and calcining at high temperature in nitrogen atmosphere to obtain the target product Nb-Mo/g-C 3 N 4 A photocatalytic material. By using the present inventionHydrochloric acid treated Nb-Mo ion co-doped g-C prepared by Ming method 3 N 4 Photocatalytic material, improved g-C 3 N 4 The method has the advantages of low cost and easy operation, and can degrade organic pollutants by natural light.)

1. Hydrochloric acid treated Nb-Mo co-doped g-C₃N₄Photocatalytic material, characterized in that the hydrochloric acid-treated Nb-Mo co-doped g-C₃N₄The photocatalysis material is doped with 0.25 to 0.5 percent of Nb ions and Mo ions according to molar percentage, wherein the ratio of Nb ions to Mo ions is 1: 1.

2. Hydrochloric acid treated Nb-Mo co-doped g-C₃N₄The preparation method of the photocatalytic material is characterized by comprising the following steps:

1) adding niobium oxide and molybdenum oxide powder into distilled water, then adding melamine, magnetically stirring at 80 ℃, and performing ultrasonic treatment to obtain a mixed solution;

2) dropwise adding a hydrochloric acid solution into the mixed solution obtained in the step 1), uniformly stirring by magnetic force, and drying to obtain a precursor;

3) grinding the precursor, and calcining at high temperature in nitrogen atmosphere to obtain the target product Nb-Mo/g-C₃N₄A photocatalytic material.

3. The method of claim 2, wherein in step 1), the niobium oxide is Nb₂O₅(ii) a The molybdenum oxide is MoO₃。

4. The process according to claim 3, wherein in step 1), Nb is added in a molar ratio₂O₅:MoO₃Melamine is 0.00125-0.0025:0.0025-0.005: 1.

5. The method of claim 2, wherein the drying temperature in step 2) is 80 ℃.

6. The process according to claim 2, wherein the molar ratio of hydrochloric acid to melamine is 0.345: 1.

7. The method of claim 2, wherein the high-temperature calcination in step 3) is performed at 550 ℃ for 2 hours.

8. The method of claim 7, wherein the temperature increase rate of the high-temperature calcination is 3 ℃/min.

9. Hydrochloric acid treated Nb-Mo codoped g-C according to claim 1₃N₄The application of the photocatalytic material in the catalytic degradation of gas pollutants under visible light.

10. The use of claim 9, wherein the gaseous contaminant is isopropanol.

Technical Field

The invention belongs to the technical field of photocatalysis, and particularly relates to high-activity Nb-Mo/g-C₃N₄A photocatalytic material and a preparation method and application thereof.

Background

Over the past decades, excessive emissions of toxic gases have created serious environmental problems that threaten human health. Various adsorbents have been studied to detect and remove toxic gases. Wherein the graphite carbon nitride (g-C)₃N₄) A graphene-like porous layered material has attracted great interest because of its ease of synthesis, attractive electronic band structure, non-toxicity and high stability. Such organic semiconductors show tremendous potential applications in a variety of fields, including photocatalytic water splitting, photoreduction of carbon dioxide, photolysis of organic contaminants, solar energy conversion, and sensors. However, its inherent structure results in high electron-hole recombination rate and low photocatalytic activity, limiting its industrial application.

Disclosure of Invention

To solve the above problems, it is an object of the present invention to provide a hydrochloric acid-treated Nb-Mo co-doped g-C₃N₄The method is easy to operate, simple, convenient, low in cost, mild in condition and beneficial to large-scale production.

The technical scheme adopted by the invention is as follows: hydrochloric acid treated Nb-Mo co-doped g-C₃N₄The photocatalysis material is doped with 0.25 to 0.5 percent of Nb ions and Mo ions according to molar percentage, wherein the ratio of Nb ions to Mo ions is 1: 1.

Hydrochloric acid treated Nb-Mo co-doped g-C₃N₄The preparation method of the photocatalytic material comprises the following steps:

1) adding niobium oxide and molybdenum oxide powder into distilled water, then adding melamine, magnetically stirring at 80 ℃, and performing ultrasonic treatment to obtain a mixed solution;

2) dropwise adding a hydrochloric acid solution into the mixed solution obtained in the step 1), uniformly stirring by magnetic force, and drying to obtain a precursor;

3) grinding the precursor, and calcining at high temperature in nitrogen atmosphere to obtain the target product Nb-Mo/g-C₃N₄A photocatalytic material.

Further, in the above preparation method, step 1), the niobium oxide is Nb₂O₅(ii) a The molybdenum oxide is MoO₃。

Further, the above-mentioned preparation method, step 1), is carried out in terms of molar ratio, Nb₂O₅:MoO₃Melamine (0.00125-0.0025): 0.0025-0.005): 1.

Further, in the preparation method, step 2), the drying temperature is 80 ℃.

Further, in the above production method, the molar ratio of hydrochloric acid to melamine is 0.345: 1.

Further, in the above preparation method, step 3), the high temperature calcination is carried out at 550 ℃ for 2 h.

Further, in the preparation method, the heating rate of the high-temperature calcination is 3 ℃/min.

The invention provides hydrochloric acid treated Nb-Mo co-doped g-C₃N₄The application of the photocatalytic material in the catalytic degradation of gas pollutants under visible light.

Further, the gaseous contaminant is isopropanol.

The invention has the beneficial effects that:

1. the invention provides hydrochloric acid treated Nb-Mo co-doped g-C₃N₄The photocatalytic material successfully constructs a doping structure with larger specific surface area, the structure can more easily move charges, and the photocatalytic activity can be effectively improved.

2. The hydrochloric acid treated Nb-Mo co-doped g-C provided by the invention₃N₄The preparation method of the photocatalytic material has the advantages of cheap and easily obtained raw materials, simple and convenient operation and greatly reduced costAnd the paint is non-toxic and pollution-free to the environment, and realizes green chemistry.

3. The invention increases g-C₃N₄The specific surface area of (a) is to improve photocatalytic performance by increasing reaction sites and promoting bulk charge separation. In order to obtain a larger specific surface area, modification and doping are effective and simple methods for improving the photocatalytic performance, because the modification and doping can cause the change of the specific surface area, the Nb-Mo ion co-doping adopted by the method can generate lattice defects, so that atoms in lattices are easier to migrate, the sensitivity to visible light is further improved, and the photocatalytic reaction efficiency is improved.

Drawings

FIG. 1 shows the photocatalyst prepared in example 1 at 0.5% Nb-Mo/g-C₃N₄、0.25％Nb-Mo/g-C₃N₄And pure g-C₃N₄XRD contrast pattern of (a).

FIG. 2 shows the results of example 2 with different photocatalysts 0.5% Nb-Mo/g-C₃N₄、0.25％Nb-Mo/g-C₃N₄And pure g-C₃N₄The acetone production rate of (2) is plotted in comparison.

Detailed Description

Example 1

Hydrochloric acid treated Nb-Mo codoped g-C₃N₄Photocatalytic material (0.5% Nb-Mo/g-C₃N₄)

The preparation method comprises the following steps:

1) adding 0.0093g (0.0001mol) Nb₂O₅And 0.0288g (0.0002mol) of MoO₃Adding the mixture into 45.5mL of distilled water, then adding 5g (0.04mol) of melamine, magnetically stirring the mixture for 1h at the temperature of 80 ℃, and performing ultrasonic treatment for 1h to obtain a mixed solution;

2) dropwise adding 4.5mL of hydrochloric acid solution into the mixed solution obtained in the step 1), uniformly stirring by magnetic force, putting into a drying oven, and drying at 80 ℃ for 12h to obtain a precursor;

3) grinding the precursor obtained in the step 2), heating to 550 ℃ at the heating rate of 3 ℃/min in the nitrogen environment, and calcining at 550 ℃ for 2h to obtain the target product Nb-Mo co-doped g-C treated by hydrochloric acid₃N₄A photocatalytic material is used as a material for the light,the samples were labeled 0.5% Nb-Mo/g-C with 0.5% Nb and Mo in mole percent₃N₄。

(II) hydrochloric acid treated Nb-Mo codoped g-C₃N₄Photocatalytic material (0.25% Nb-Mo/g-C₃N₄)

The preparation method comprises the following steps:

1) 0.0046g (0.00005mol) of Nb₂O₅And 0.0144g (0.0001mol) MoO₃Adding the mixture into 45.5mL of distilled water, then adding 5g (0.04mol) of melamine, magnetically stirring the mixture for 1h at the temperature of 80 ℃, and performing ultrasonic treatment for 1h to obtain a mixed solution;

2) dropwise adding 4.5mL of hydrochloric acid solution into the mixed solution obtained in the step 1), uniformly stirring by magnetic force, putting into a drying oven, and drying at 80 ℃ for 12h to obtain a precursor;

3) grinding the precursor obtained in the step 2), heating to 550 ℃ at the heating rate of 3 ℃/min in the nitrogen environment, and calcining at 550 ℃ for 2h to obtain the target product Nb-Mo co-doped g-C treated by hydrochloric acid₃N₄Photocatalytic material, in mole percent, containing 0.25% Nb and Mo, sample designation 0.25% Nb-Mo/g-C₃N₄

(III) comparative example pure g-C₃N₄Photocatalytic material

The preparation method comprises the following steps: placing 5g of melamine in a crucible, heating to 550 ℃ at the heating rate of 3 ℃/min in a nitrogen environment, and calcining for 2h to obtain pure g-C₃N₄A photocatalytic material.

(IV) detection

FIG. 1 is a graph of sample 0.5% Nb-Mo/g-C₃N₄Sample 0.25% Nb-Mo/g-C₃N₄And pure g-C₃N₄XRD test pattern of (1), sample 2.5% Nb-Mo/g-C₃N₄And sample 0.5% Nb-Mo/g-C₃N₄Two diffraction peaks at 13.1 ℃ and 27.3 ℃ with pure g-C₃N₄The diffraction peaks coincide and the main peak remains for the doped g-C3N4 catalyst, indicating that the crystal structure is unchanged. No compounds of Nb and Mo were observed in the doped g-C3N4 material, indicating that Nb and Mo are intercalated in ionic formInto g-C3N4 crystal planes.

Example 2 application

Effect of different catalysts on catalytic degradation of isopropanol under visible light

The test process is as follows: a 300W xenon lamp is used as a light source to filter out ultraviolet simulation sunlight, photocurrent is adjusted to 18mA position, a light intensity center is adjusted to irradiate the surface of a sample, the position is fixed, and 0.5 percent of Nb-Mo/g-C prepared in the embodiment 1 is respectively added₃N₄、0.25％Nb-Mo/g-C₃N₄And pure g-C₃N₄Placing in a 4cm container²In the glass tank, the glass tanks carrying the photocatalyst were placed in 325cm each³And finally, injecting 5ul of isopropanol liquid into the reactor, waiting for 2 hours until the isopropanol is completely volatilized into gas, starting timing after 20 minutes of illumination, and extracting one needle of the sample every 20 minutes for testing. The peak area of acetone generated by degrading isopropanol is recorded, and the concentration change point line graph of acetone generated by degrading isopropanol is calculated, and the result is shown in figure 2.

As can be seen from FIG. 2, the hydrochloric acid treated 0.5% Nb-Mo/g-C prepared in accordance with the present invention₃N₄g of photocatalytic material with a continuously increasing concentration of acetone produced over time and all being purer g-C₃N₄The effect is good. g-C prepared by the invention₃N₄Not only improves the photocatalytic activity, but also improves the yield to 1.5 times, improves the g-C₃N₄Photocatalytic performance.