阅读说明：本技术 一种CdS/ZnCr LDH复合光催化剂的制备方法及其产品与应用 (Preparation method of CdS/ZnCr LDH composite photocatalyst, product and application thereof ) 是由 陈海群 何光裕 左园杰 朱俊武 付永胜 郝青丽 陈群 于 2019-10-24 设计创作，主要内容包括：本发明公开了一种CdS/ZnCr LDH复合光催化剂的制备方法及其产品与应用,包括将硫源和镉盐溶解在乙二胺溶液中,搅拌,进行溶剂热反应；抽滤、洗涤和干燥后研磨,得CdS纳米线；将CdS纳米线超声分散在水中,加入锌盐、铬盐,搅拌；调节pH,搅拌,进行水热反应抽滤,收集沉淀物,洗涤,干燥得到复合光催化剂,本发明以ZnCr LDH修饰CdS纳米线,构建异质结,ZnCr LDH的负载有效的抑制了CdS中光生电子空穴对的复合,提升了材料的光催化性能,CdS/ZnCr LDH复合光催化剂在可见光下还原六价铬以测试其光催化性能,发现在30分钟内六价铬的去除率可达100％。(The invention discloses a preparation method of a CdS/ZnCr LDH composite photocatalyst, a product and an application thereof, which comprises the steps of dissolving a sulfur source and a cadmium salt in an ethylenediamine solution, stirring, and carrying out a solvothermal reaction; carrying out suction filtration, washing, drying and grinding to obtain CdS nanowires; ultrasonically dispersing CdS nanowires in water, adding zinc salt and chromium salt, and stirring; the method comprises the steps of regulating pH, stirring, carrying out hydrothermal reaction and suction filtration, collecting precipitates, washing and drying to obtain the composite photocatalyst, wherein ZnCr LDH is used for modifying CdS nanowires to construct a heterojunction, the load of ZnCr LDH effectively inhibits the recombination of photogenerated electron hole pairs in CdS, the photocatalytic performance of the material is improved, and the CdS/ZnCr LDH composite photocatalyst reduces hexavalent chromium under visible light to test the photocatalytic performance of the CdS/ZnCr LDH composite photocatalyst, and the removal rate of the hexavalent chromium can reach 100% within 30 minutes.)

1. A preparation method of a CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

dissolving a sulfur source and cadmium salt in an ethylenediamine solution, stirring, and carrying out a solvothermal reaction;

carrying out suction filtration, washing, drying and grinding to obtain CdS nanowires;

ultrasonically dispersing CdS nanowires in water, adding zinc salt and chromium salt, and stirring;

adjusting the pH, stirring and carrying out hydrothermal reaction;

and (4) carrying out suction filtration, collecting the precipitate, washing and drying to obtain the CdS/ZnCr LDH composite photocatalyst.

2. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claim 1, wherein the preparation method comprises the following steps: the cadmium salt comprises one or more of cadmium acetate, cadmium sulfate, cadmium nitrate and cadmium bromide; the sulfur source comprises one or more of thiourea, thioacetamide, cysteine and sodium sulfide; the zinc salt comprises one or more of zinc nitrate, zinc sulfate, zinc chloride and zinc acetate; the chromium salt comprises one or more of chromium nitrate, chromium sulfate, chromium chloride and chromium acetate; the pH is adjusted by NaOH and Na as the adjusting agent₂CO₃The mixed base of (1).

3. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claim 1 or 2, wherein the CdS/ZnCr LDH composite photocatalyst comprises the following steps: the molar ratio of the cadmium salt to the thiourea is 1: 2-1: 5.

4. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claims 1-3, wherein the CdS/ZnCr LDH composite photocatalyst comprises the following steps: the molar ratio of the cadmium salt to the thiourea is 1:3, the thermal reaction is carried out in a solvent, the reaction temperature is 180 ℃, and the reaction time is 24 hours.

5. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claim 1, wherein the preparation method comprises the following steps: the CdS nanowires are subjected to ultrasonic treatment in distilled water, the ultrasonic power is 250W, the ultrasonic time is 1h, and the ultrasonic frequency is 40 KHz.

6. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claim 1, wherein the preparation method comprises the following steps: the molar ratio of the added zinc salt to the added chromium salt is 1: 1-3: 1, the pH is adjusted to 8-10, and the hydrothermal reaction is carried out at the reaction temperature of 100-160 ℃ for 10-16 h.

7. The method for preparing the CdS/ZnCr LDH composite photocatalyst as defined in claim 6, wherein the CdS/ZnCr LDH composite photocatalyst comprises the following components in parts by weight: the molar ratio of the added zinc salt to the added chromium salt is 2:1, the pH value is adjusted to 9, and the hydrothermal reaction is carried out at the reaction temperature of 120 ℃ for 12 hours.

8. The preparation method of the CdS/ZnCr LDH composite photocatalyst as defined in claim 1, wherein the preparation method comprises the following steps: and drying at the drying temperature of 60-80 ℃ for 8-12 h.

9. The CdS/ZnCr LDH composite photocatalyst prepared by the preparation method of the CdS/ZnCr LDH composite photocatalyst as claimed in claim 1, is characterized in that: according to the CdS/ZnCr LDH composite photocatalyst, ZnCr LDH is dispersed on the surface of a CdS nanowire, the diameter of the CdS/ZnCr LDH composite photocatalyst is 30-50 nm, and the length of the CdS/ZnCr LDH composite photocatalyst is 0.5-1 mu m.

10. The use of the CdS/ZnCr LDH composite photocatalyst of claim 9 in the reduction of hexavalent chromium.

Technical Field

The invention belongs to the field of photocatalysts, and particularly relates to a preparation method of a CdS/ZnCr LDH composite photocatalyst, and a product and application thereof.

Background

With the rapid development of urbanization and industrialization, the pollution of various heavy metal ions in water is becoming serious and becomes a global environmental pollution problem. Among many heavy metal ion contaminations, hexavalent chromium (cr (vi)) has threatened the healthy life of human beings due to its high stability, toxicity and carcinogenicity. Therefore, researchers have sought many methods for removing cr (vi) from water, such as adsorption, chemical precipitation, and ion exchange. However, these conventional methods have some disadvantages, such as incomplete treatment, high cost, and secondary pollution. In contrast to these conventional methods, photocatalytic reduction has attracted attention as a green, efficient and promising technology.

CdS as a novel semiconductor photocatalytic material has received great attention in the field of visible light photocatalysis due to a series of advantages of moderate band gap (2.4eV), capability of effectively absorbing visible light, controllable morphology and the like. However, its low visible light utilization rate, high photo-generated electron-hole recombination rate, and high photo-corrosion property seriously hinder its application in photocatalysis. By improving the preparation method, doping, noble metal loading and other technologies, the visible light absorption performance of the CdS semiconductor material can be effectively improved or the recombination of photo-generated electrons and holes can be inhibited, so that the photocatalytic performance of the CdS semiconductor material is further improved. These methods can improve the photocatalytic performance of the catalyst to some extent, but the reactivity of the catalyst and the cost of the catalyst still cannot meet the actual requirements.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made in view of the above and/or other problems occurring in the prior art photocatalysts.

Therefore, one of the purposes of the invention is to overcome the defects of the existing photocatalyst product and provide a preparation method of the CdS/ZnCr LDH composite photocatalyst.

To solve the above technical problem, according to an aspect of the present invention, the present invention provides the following technical solutions: a preparation method of a CdS/ZnCr LDH composite photocatalyst comprises the following steps,

dissolving a sulfur source and cadmium salt in an ethylenediamine solution, stirring, and carrying out a solvothermal reaction;

carrying out suction filtration, washing, drying and grinding to obtain CdS nanowires;

ultrasonically dispersing CdS nanowires in water, adding zinc salt and chromium salt, and stirring;

adjusting pH, stirring, and performing hydrothermal reaction

And (4) carrying out suction filtration, collecting the precipitate, washing and drying to obtain the CdS/ZnCr LDH composite photocatalyst.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the cadmium salt comprises one or more of cadmium acetate, cadmium sulfate, cadmium nitrate and cadmium bromide; the sulfur source comprises one or more of thiourea, thioacetamide, cysteine and sodium sulfide; the zinc salt comprises one or more of zinc nitrate, zinc sulfate, zinc chloride and zinc acetate; said chromium salt comprisesOne or more of chromic nitrate, chromic sulfate, chromic chloride and chromic acetate; the pH is adjusted by NaOH and Na as the adjusting agent₂CO₃The mixed base of (1).

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the molar ratio of the cadmium salt to the thiourea is 1: 2-1: 5.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the molar ratio of the cadmium salt to the thiourea is 1:3, the thermal reaction is carried out in a solvent, the reaction temperature is 180 ℃, and the reaction time is 24 hours.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the CdS nanowires are subjected to ultrasonic treatment in distilled water, the ultrasonic power is 250W, the ultrasonic time is 1h, and the ultrasonic frequency is 40 KHz.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the molar ratio of the added zinc salt to the added chromium salt is 1: 1-3: 1, the pH is adjusted to 8-10, and the hydrothermal reaction is carried out at the reaction temperature of 100-160 ℃ for 10-16 h.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: the molar ratio of the added zinc salt to the added chromium salt is 2:1, the pH value is adjusted to 9, and the hydrothermal reaction is carried out at the reaction temperature of 120 ℃ for 12 hours.

The preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps of: and drying at the drying temperature of 60-80 ℃ for 8-12 h.

The CdS/ZnCr LDH composite photocatalyst prepared by the preparation method of the CdS/ZnCr LDH composite photocatalyst is characterized by comprising the following steps: according to the CdS/ZnCr LDH composite photocatalyst, ZnCr LDH is dispersed on the surface of a CdS nanowire, the diameter of the CdS/ZnCr LDH composite photocatalyst is 30-50 nm, and the length of the CdS/ZnCr LDH composite photocatalyst is 0.5-1 mu m.

As another aspect of the invention, the invention provides an application of the CdS/ZnCr LDH composite photocatalyst in reduction of hexavalent chromium.

The invention has the beneficial effects that: the CdS/ZnCr LDH nano composite material prepared by the method has regular shape and uniform distribution of all components, and the CdS/ZnCr LDH in the composite material has good synergistic effect, so that the photocatalysis performance of the composite material is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is an XRD pattern of CdS prepared in example 1 and (3:1) CdS/ZnCr LDH composite photocatalyst prepared in example 3;

FIG. 2 is an SEM image of the (3:1) CdS/ZnCr LDH composite photocatalyst prepared in example 3;

FIG. 3 is a degradation diagram of CdS and ZnCr LDH composite photocatalysts prepared in examples 1-5 and CdS/ZnCr LDH composite photocatalysts with different mass ratios.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, specific embodiments thereof are described in detail below with reference to examples of the specification.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.