阅读说明：本技术 一种钒酸铋、磷酸铋复合物可见光催化剂的微波合成方法 (Microwave synthesis method of bismuth vanadate and bismuth phosphate compound visible-light-driven photocatalyst ) 是由 廖学红 廖万鹏 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种钒酸铋、磷酸铋复合物可见光催化剂的微波合成方法,包括以下步骤：(1)将表面活性剂加入到稀硝酸中,超声分散溶解,再加入硝酸铋,超声分散溶解,得到溶液A；(2)将偏钒酸铵、磷酸氢二钠加入到水中,超声分散溶解,得到溶液B；(3)将B溶液缓慢加入到溶液A中混合均匀得到溶液C；(4)将溶液C转入圆底烧瓶中,微波辐照,加热回流得到回流液；(5)将回流液的上层清液除去,离心分离,用纯水洗涤沉淀,再经脱水、干燥后即得。本发明提供的方法简单、高效、节能、环保,制备时间大幅缩短,所制备的产品光催化性能好,催化性能高。(The invention discloses a microwave synthesis method of a bismuth vanadate and bismuth phosphate compound visible-light-driven photocatalyst, which comprises the following steps: (1) adding a surfactant into dilute nitric acid, performing ultrasonic dispersion and dissolution, adding bismuth nitrate, and performing ultrasonic dispersion and dissolution to obtain a solution A; (2) adding ammonium metavanadate and disodium hydrogen phosphate into water, and performing ultrasonic dispersion and dissolution to obtain a solution B; (3) slowly adding the solution B into the solution A, and uniformly mixing to obtain a solution C; (4) transferring the solution C into a round-bottom flask, performing microwave irradiation, and heating and refluxing to obtain a reflux liquid; (5) removing supernatant of the reflux liquid, centrifuging, washing the precipitate with pure water, dehydrating, and drying. The method provided by the invention is simple, efficient, energy-saving and environment-friendly, the preparation time is greatly shortened, and the prepared product has good photocatalytic performance and high catalytic performance.)

1. A microwave synthesis method of a bismuth vanadate and bismuth phosphate compound visible light catalyst is characterized by comprising the following steps:

(1) adding a surfactant into dilute nitric acid, performing ultrasonic dispersion and dissolution, adding bismuth nitrate, and performing ultrasonic dispersion and dissolution to obtain a solution A;

(2) adding ammonium metavanadate and disodium hydrogen phosphate into water, and performing ultrasonic dispersion and dissolution to obtain a solution B;

(3) slowly adding the solution B into the solution A, and uniformly mixing to obtain a solution C;

(4) transferring the solution C into a round-bottom flask, performing microwave irradiation, and heating and refluxing to obtain a reflux liquid;

(5) removing supernatant of the reflux liquid, centrifuging, washing the precipitate with pure water, dehydrating, and drying.

2. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: the surfactant is sodium dodecyl sulfate.

3. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: in the step (1), the concentration of the dilute nitric acid is 1mol/L, and the surfactant: dilute nitric acid: bismuth nitrate (1 g), 50ml and 4.85 g.

4. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: in the step (2), the ratio of the ammonium metavanadate to the disodium hydrogen phosphate to the water is 0.58g to 1.79g to 50 mL.

5. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: the molar ratio of bismuth ions in the solution A to vanadate ions in the solution B is 2: 1.

6. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: in the step (4), the microwave irradiation works intermittently, 30s is taken as a working period, the operation lasts 12s, the operation stops 18s, and the microwave power is 650W.

7. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: the microwave irradiation time in the step (4) is 20 minutes.

8. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: and (5) washing with pure water for 4-5 times.

9. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: and (5) the dehydration solvent is acetone.

10. The microwave synthesis method of the bismuth vanadate-bismuth phosphate composite visible-light-driven photocatalyst according to claim 1, wherein the microwave synthesis method comprises the following steps: in the step (5), the drying temperature is 80 ℃, and the drying time is 8 hours.

Technical Field

The invention belongs to the field of inorganic synthesis, and particularly relates to a microwave synthesis method of a bismuth vanadate and bismuth phosphate compound visible-light-driven photocatalyst.

Background

BiVO₄Has a forbidden band width of 2.4eV, and has the characteristics of cheaper price, higher light utilization rate, reusability and simpler production. BiVO₄Has good catalytic activity under the irradiation of visible light, is nontoxic, harmless and noncorrosive, can be repeatedly used, and can completely mineralize pollutants into H₂O、CO₂。

The bismuth phosphate photocatalyst has higher electron-hole separation rate. The phosphate in bismuth phosphate carries a large negative charge, which greatly increases the dipole moment of bismuth phosphate, which positively promotes the separation of electron-hole pairs, which then leads to a higher photocatalytic activity. PO (PO)₄ ^3-The material has strong hydrophilicity, can generate electrostatic attraction to attract photogenerated holes, and can effectively promote the separation of photogenerated carriers from the original carrier. Many research practices have shown that BiPO₄Has good degradation effect on organic substances, such as: phenols, benzenes, dyes, polystyrene films, pharmaceuticals, and the like. And BiPO₄Due to the characteristics of low cost and high activity, the material still has some defects in practical application, such as wider band gap (Eg ═ 3.85eV), sensitivity only to ultraviolet light, low light energy utilization rate and the like.

The method for preparing the bismuth vanadate and the bismuth phosphate comprises the following steps: sol-gel method, hydrothermal method, solvothermal method, high-temperature solid phase method, liquid precipitation method, ultrasonic synthesis method, microemulsion method, etc. The above-mentioned preparation methods have a common problem, are time-consuming and energy-consuming.

Disclosure of Invention

In order to solve the technical problems, the invention provides a microwave synthesis method of a bismuth vanadate and bismuth phosphate compound visible-light-driven photocatalyst. The synthesis method utilizes microwave irradiation as a reaction condition, and can quickly and efficiently synthesize the bismuth vanadate and bismuth phosphate compound with good photocatalytic effect by combining the dispersion effect of the surfactant SDS.

The technical scheme provided by the invention is as follows:

a microwave synthesis method of a bismuth vanadate and bismuth phosphate compound visible light catalyst comprises the following steps:

(1) adding a surfactant into dilute nitric acid, performing ultrasonic dispersion and dissolution, adding bismuth nitrate, and performing ultrasonic dispersion and dissolution to obtain a solution A;

(2) adding ammonium metavanadate and disodium hydrogen phosphate into water, and performing ultrasonic dispersion and dissolution to obtain a solution B;

(3) slowly adding the solution B into the solution A, and uniformly mixing to obtain a solution C;

(4) transferring the solution C into a round-bottom flask, performing microwave irradiation, and heating and refluxing to obtain a reflux liquid;

(5) removing supernatant of the reflux liquid, centrifuging, washing the precipitate with pure water, dehydrating, and drying.

Specifically, the surfactant is sodium dodecyl sulfate.

Specifically, in the step (1), the concentration of the dilute nitric acid is 1mol/L, and the surfactant: dilute nitric acid: bismuth nitrate (1 g), 50ml and 4.85 g.

Specifically, in the step (2), the ratio of ammonium metavanadate to disodium hydrogen phosphate to water is 0.58g to 1.79g to 50 mL.

Specifically, the molar ratio of bismuth ions in the solution A to vanadate ions in the solution B is 2: 1.

Specifically, in the step (4), the microwave irradiation is operated intermittently, with 30s as one operating cycle, for 12s, and stopped for 18s, and the microwave power is 650W.

Specifically, the microwave irradiation time in the step (4) is 20 minutes.

Specifically, the number of times of washing with pure water in the step (5) is 4-5.

Specifically, the dehydration solvent in the step (5) is acetone.

Specifically, in the step (5), the drying temperature is 80 ℃ and the drying time is 8 hours.

The invention has the beneficial effects that:

(1) by adopting the reaction condition of intermittent microwave irradiation, on one hand, the reaction energy barrier is reduced by utilizing the microwaves, the reaction speed is greatly increased, the reaction time is greatly shortened, and the reaction efficiency is improved; on the other hand, the intermittent irradiation can effectively control the intensity of the reaction, give consideration to the stable reaction and the stable reaction system, and can save energy and reduce consumption;

(2) SDS is selected as a surfactant to achieve the purpose of a good dispersion system, and the photocatalytic performance of a product prepared by utilizing the SDS is obviously better than that of other surfactants;

(3) the synthetic method is simple, efficient, energy-saving and environment-friendly.

Drawings

FIG. 1 is an XRD pattern of the product prepared in example 1;

FIG. 2 is an SEM photograph of the product prepared in example 1;

FIG. 3 is BiVO prepared in example 1₄/BiPO₄Photocatalytic degradation curve.

Detailed Description

The invention will be further illustrated with reference to specific examples, to which the present invention is not at all restricted.