阅读说明：本技术 一种负载铋系异质结的氧化石墨烯光催化材料及其制备方法和应用 (bismuth-series heterojunction-loaded graphene oxide photocatalytic material and preparation method and application thereof ) 是由 张惠宁 尹鑫 韩建平 吴志国 高世铭 闫鹏勋 张登启 杨亚红 胡家玮 王少峰 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种负载铋系异质结的氧化石墨烯光催化材料的制备方法,包括以下步骤：首先制备BiOI/BixNbOy光催化剂和氧化石墨烯,将合成的BiOI/BixNbOy异质结催化剂负载于氧化石墨烯纳米片上,以负载后的石墨烯纳米片为前驱体,对预冷冻处理后的化合物进行真空干燥处理,得到具有高强度的负载铋系异质结的氧化石墨烯光催化材料。本发明负载铋系异质结的氧化石墨烯光催化材料具有高强度、高比表面积和强吸附等特点,可以有效解决粉末状光催化剂在使用后难以分离和回收利用的难题,避免了纳米材料对环境造成的二次污染等问题；有利于提高光催化反应速率；提高了催化剂光生载流子的分离率,增加了光催化剂的的稳定性,拓宽了光谱响应范围。(The invention discloses a preparation method of a bismuth-series heterojunction-loaded graphene oxide photocatalytic material, which comprises the following steps of: firstly, preparing a BiOI/BixNbOy photocatalyst and graphene oxide, loading the synthesized BiOI/BixNbOy heterojunction catalyst on a graphene oxide nano-sheet, taking the loaded graphene nano-sheet as a precursor, and carrying out vacuum drying treatment on the pre-frozen compound to obtain the high-strength bismuth-series heterojunction-loaded graphene oxide photocatalytic material. The bismuth-series heterojunction-loaded graphene oxide photocatalytic material has the characteristics of high strength, high specific surface area, strong adsorption and the like, can effectively solve the problem that a powdery photocatalyst is difficult to separate and recycle after being used, and avoids the problems of secondary pollution and the like caused by a nano material to the environment; the photocatalytic reaction rate is improved; the separation rate of the photo-generated carriers of the catalyst is improved, the stability of the photocatalyst is improved, and the spectral response range is widened.)

1. A preparation method of a bismuth-series heterojunction-loaded graphene oxide photocatalytic material is characterized by comprising the following steps:

First preparing BiOI/Bi_xNbO_yPhotocatalyst and graphene oxide, synthesized BiOI/Bi_xNbO_yAnd (2) loading the heterojunction catalyst on the graphene oxide nanosheets, taking the loaded graphene nanosheets as precursors, and performing vacuum drying treatment on the pre-frozen compounds by adopting a directional vacuum freeze-drying technology to obtain the bismuth-series heterojunction-loaded graphene oxide photocatalytic material with high strength.

2. The preparation method of the bismuth-based heterojunction-supported graphene oxide photocatalytic material according to claim 1, wherein Nb is adopted₂O₅And Bi₅(NO₃)₃·5H₂O preparation of BiOI/Bi_xNbO_yPhotocatalyst and process for producing the same。

3. The method for preparing the bismuth-based heterojunction-supporting graphene oxide photocatalytic material of claim 1, wherein the BiOI/Bi_xNbO_yAdding a surfactant in the preparation process of the photocatalyst to synthesize the BiOI/Bi_xNbO_yA heterojunction photocatalyst.

4. The preparation method of the graphene oxide photocatalytic material loaded with the bismuth-based heterojunction as claimed in claim 1, wherein the surfactant is sodium citrate, sodium dodecyl benzene sulfonate or hexadecyl trimethylamine bromide.

5. The preparation method of the bismuth-based heterojunction-supported graphene oxide photocatalytic material as claimed in claim 1, wherein the vacuum degree is 3.3-13 pa in the vacuum freeze drying process.

6. A bismuth-based heterojunction-supported graphene oxide photocatalytic material prepared by the method of any one of claims 1 to 5.

7. The graphene oxide photocatalytic material loaded with bismuth-based heterojunction as claimed in claim 6 is applied to degradation of POPs in water.

Technical Field

The invention relates to a preparation method of a photocatalytic material, in particular to preparation and application of a bismuth-series heterojunction-loaded graphene oxide photocatalytic material.

Background

Persistent Organic Pollutants (POPs) are a general term for natural or synthetic organic substances and derivatives thereof with long-term residue, large-scale mobility, bioaccumulation, semi-volatility and high toxicity to living organisms, and the POPs pollution gradually becomes a new global environmental problem which is currently and internationally concerned. With the rapid development of domestic industrial and agricultural economy, the discharge of POPs in related water bodies through various ways is continuously increased, the pollution condition presents a worsening trend, and the caused health problems become more serious day by day, and research show that the surface water environment is generally polluted by persistent organic matters, and the water quality of water source water and underground water also faces severe tests.

Photocatalytic degradation is an important conversion pathway of POPs in the environment, and is also the most commonly used chemical degradation method. The existing conventional photocatalyst, niobium-series and bismuth-series composite oxides or heterojunction, graphene oxide-based composite catalyst and the like have certain defects. Therefore, the preparation of the novel photocatalyst which is nontoxic and stable, high in catalytic activity, high in green energy utilization rate and good in recycling performance has important significance for realizing efficient degradation of POPs in water. The invention aims to prepare a bismuth-loaded heterojunction-loaded graphene oxide photocatalytic material with high-efficiency catalytic performance.

Disclosure of Invention

The invention aims to overcome the defects of narrow spectral response range, poor recycling property, secondary pollution of generated water, low carrier separation efficiency and the like of the existing photocatalytic material, and provides a preparation method of an efficient bismuth-series heterojunction-loaded graphene oxide photocatalytic material.

The invention is realized by the following technical scheme.

A preparation method of a bismuth-series heterojunction-loaded graphene oxide photocatalytic material comprises the following steps:

First preparing BiOI/Bi_xNbO_yThe method comprises the steps of loading a synthesized BiOI/BixNbOy heterojunction catalyst on a graphene oxide nano-sheet, taking the loaded graphene nano-sheet as a precursor, and performing vacuum drying treatment on a pre-frozen compound by means of a directional vacuum freeze-drying technology to obtain the high-strength bismuth-series heterojunction-loaded graphene oxide photocatalytic material.

Preferably, Nb is used₂O₅And Bi (NO)₃)₃·5H₂O preparation of BiOI/Bi_xNbO_yA photocatalyst.

Preferably, BiOI/Bi_xNbO_yDifferent surfactants are respectively added or different reaction conditions (such as reaction) are respectively controlled in the preparation process of the photocatalystTemperature, time, reactant ratio, etc.) to synthesize BiOI/Bi with different crystal forms_xNbO_yA heterojunction photocatalyst.

Preferably, the surfactant is sodium citrate, sodium dodecylbenzene sulfonate or cetyltrimethylammonium bromide.

Preferably, the vacuum degree is 3.3-13 pa in the vacuum freeze drying process.

The bismuth-series heterojunction-loaded graphene oxide photocatalytic material prepared by the method.

The bismuth-series heterojunction-loaded graphene oxide photocatalytic material is mainly applied to degradation of POPs (persistent organic pollutants) in a water body.

BiOI/Bi in the preparation method of the invention_xNbO_ythe load of the method is combined with the directional vacuum freeze drying technology, so that the mechanical strength of the graphene-based catalyst can be greatly improved.

The graphene oxide-based load in the preparation method can improve BiOI/Bi_xNbO_yDegree of catalyst dispersion and uniformity of dispersion.

Compared with the prior art, the technical scheme provided by the invention has the advantages that:

(1) The constructed bismuth-series heterojunction-loaded graphene oxide photocatalytic material has the characteristics of high strength, high specific surface area, strong adsorption and the like, can effectively solve the problem that the powdery photocatalyst is difficult to separate and recycle after being used, and avoids the problems of secondary pollution and the like caused by a nano material to the environment.

(2) Compared with the traditional photocatalyst carrier (such as activated carbon), the graphene oxide carrier is easier to transfer mass, and is beneficial to improving the photocatalytic reaction rate.

(3) Utilizing high-strength graphene oxide as BiOI/Bi_xNbO_yThe carrier combines the excellent photoelectric properties and structural characteristics of the two, improves the separation rate of the photo-generated carriers of the catalyst, increases the stability of the photocatalyst, and widens the spectral response range.

Drawings

FIG. 1 shows GO-BiOI/Bi_xNbO_ySynthesis of photocatalyst and reduction of POPs by using sameAnd (4) a mechanism diagram is shown.

Detailed Description