阅读说明：本技术 铁酸锌-硫化镉纳米球复合可见光催化剂的制备方法 (Preparation method of zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst ) 是由 邵敏 徐炎华 刘志英 崔浩洁 李忠玉 徐松 于 2019-09-27 设计创作，主要内容包括：本发明涉及铁酸锌-硫化镉纳米球复合可见光催化剂的制备方法,包括硫化镉纳米球光催化剂的制备；以及铁酸锌-硫化镉纳米球复合光催化剂的制备。该制备方法简单、成本较低、操作简便,且制备条件容易获得和控制,所制备的铁酸锌-硫化镉纳米球复合可见光催化剂为绿色无污染高性能催化剂,且光催化活性高,降解时间短效果好,具有磁性,易于回收,具有潜在的应用前景。(The invention relates to a preparation method of a zinc ferrite-cadmium sulfide nanosphere composite visible light catalyst, which comprises the steps of preparing the cadmium sulfide nanosphere photocatalyst; and the preparation of the zinc ferrite-cadmium sulfide nanosphere composite photocatalyst. The preparation method is simple, the cost is low, the operation is simple and convenient, the preparation conditions are easy to obtain and control, the prepared zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst is a green pollution-free high-performance catalyst, the photocatalytic activity is high, the degradation time is short, the effect is good, the magnetism is realized, the recovery is easy, and the potential application prospect is realized.)

1. The preparation method of the zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst comprises the following specific steps of:

(1) Preparing cadmium sulfide nanospheres: adding a cadmium source and thiourea into distilled water, stirring to dissolve the cadmium source and the thiourea, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 20-28 h at 120-160 ℃, cooling, centrifuging, washing and drying;

(2) Preparing a zinc ferrite-cadmium sulfide nanosphere composite photocatalyst: adding the cadmium sulfide nanospheres prepared in the step (1) into distilled water, and performing ultrasonic treatment to completely disperse the cadmium sulfide nanospheres; and then adding zinc salt and ferric salt into the solution respectively, stirring to completely dissolve the zinc salt and the ferric salt, continuously dropwise adding a sodium hydroxide solution, stirring again, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 13-17 h at 160-200 ℃, cooling, centrifuging, washing and drying to obtain the product.

2. the method of claim 1, wherein: the mol ratio of the cadmium source to the thiourea in the step (1) is 1: (4-6).

3. The method of claim 1, wherein: the cadmium source in the step (1) is cadmium acetate, cadmium chloride or cadmium nitrate.

4. The method of claim 1, wherein: the adding amount of the cadmium sulfide in the step (2) is that the mass ratio of zinc ferrite to cadmium sulfide in the product is 0.1-0.4: 1; the adding amount of the zinc salt and the iron salt is controlled to be 1: 2.

5. The method of claim 1, wherein: the zinc salt in the step (2) is zinc nitrate, zinc sulfate, zinc chloride or zinc acetate; the iron salt is ferric chloride or ferric nitrate.

6. the method of claim 1, wherein: dropwise adding a sodium hydroxide solution in the step (2) with the molar concentration of 2-3 mol/L; and stirring for 0.5-1 h.

Technical Field

The invention belongs to the technical field of photocatalytic inorganic nano materials, and relates to a preparation method of a zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst.

Background

The current energy crisis and environmental pollution are two major bottlenecks that restrict human development. On one hand, the photocatalysis technology can decompose water to generate hydrogen through solar energy, and solves the problem of fossil energy exhaustion; on the other hand, the organic pollutants can be degraded, and the method becomes a cheap and feasible way for solving the problem of environmental pollution. Therefore, the photocatalytic technology is expected to become one of the most effective methods for solving the energy crisis and the environmental pollution.

Cadmium sulfide has a forbidden band width of about 2.4eV, and has a maximum absorption peak at 514nm for light, so that electrons in the valence band can be transited to the conduction band by visible light and ultraviolet light having a wavelength less than 514nm, and in view of this characteristic, CdS can be used as a catalyst for natural light (sunlight) catalytic reaction. Meanwhile, the energy level change and the energy gap widening caused by the quantum size effect enhance the oxidation-reduction capability of the semiconductor material, so that the nano cadmium sulfide semiconductor material has excellent photocatalytic performance. However, cadmium sulfide has the defects of easy occurrence of photo-corrosion, easy recombination of photo-generated charges and holes and the like, and the photocatalytic efficiency of cadmium sulfide is seriously influenced. Cadmium sulfide and semiconductor materials with different energy band structures are compounded to form a heterojunction, and separation and transfer of photo-generated electron hole pairs are promoted, so that the photocatalytic activity of the photo-generated electron hole pairs is effectively improved.

the nano-scale ferrite shows a plurality of novel characteristics in the aspects of light, heat, electricity, magnetism and the like, and has attracted general attention in recent years. Zinc ferrite is a kind of ferrite, has spinel structure and may be represented by ZnFe₂O₄And (4) showing. The crystal lattice of zinc ferrite is a more complex face-centered cubic structure, each corner and center of each face of the cube are oxygen atoms, and iron atoms and zinc atoms are positioned in gaps of the oxygen atoms. ZnFe₂O₄forbidden band width of 1.9eV, has potential visible light catalytic activity, and ZnFe₂O₄The outstanding characteristics are stable property, no toxicity, no chemical corrosion and no photochemical corrosion. But it is used alone to catalyze the degradation of pollutants with poor results. At present, the photocatalytic performance of zinc ferrite is improved mainly by methods such as noble metal deposition, doping, compounding and the like.

disclosure of Invention

The technical problem to be solved by the invention is as follows: based on the problems, the preparation method for preparing the zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst is provided. The zinc ferrite/cadmium sulfide composite visible-light-driven photocatalyst is prepared by adopting an in-situ precipitation method, and can be applied to the technology of photocatalytic degradation of organic matters.

the technical scheme of the invention is as follows: the preparation method of the zinc ferrite-cadmium sulfide nanosphere composite visible-light-driven photocatalyst comprises the following specific steps of:

(1) Preparing cadmium sulfide nanospheres: adding a cadmium source and thiourea into distilled water, stirring to dissolve the cadmium source and the thiourea, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 20-28 h at 120-160 ℃, cooling, centrifuging, washing and drying;

(2) Preparing a zinc ferrite-cadmium sulfide nanosphere composite photocatalyst: adding the cadmium sulfide nanospheres prepared in the step (1) into distilled water, and performing ultrasonic treatment to completely disperse the cadmium sulfide nanospheres; and then adding zinc salt and ferric salt into the solution respectively, stirring to completely dissolve the zinc salt and the ferric salt, continuously dropwise adding a sodium hydroxide solution, stirring again, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 13-17 h at 160-200 ℃, cooling, centrifuging, washing and drying to obtain the product.

Preferably, the molar ratio of the cadmium source to the thiourea in step (1) is 1: (4-6).

Preferably, the cadmium source in the step (1) is cadmium acetate, cadmium chloride or cadmium nitrate.

Preferably, the amount of distilled water added in step (1) is about 80% of the fullness of the hydrothermal reaction kettle.

Preferably, the adding amount of the cadmium sulfide in the step (2) is that the mass ratio of zinc ferrite to cadmium sulfide in the product is 0.1-0.4: 1; the adding amount of the zinc salt and the iron salt is controlled to be 1: 2.

Preferably, the zinc salt in the step (2) is zinc nitrate, zinc sulfate, zinc chloride or zinc acetate; the iron salt is ferric chloride or ferric nitrate.

Preferably, the molar concentration of the dropwise added sodium hydroxide solution in the step (2) is 2-3 mol/L; the time for stirring is preferably 0.5-1 h.

Preferably, the adding amount of the distilled water in the step (2) is about 60 percent of the fullness of the hydrothermal reaction kettle; after the sodium hydroxide solution is dripped, the fullness of the hydrothermal reaction kettle is about 70 percent.

Has the advantages that:

The preparation method is simple, the cost is low, the operation is simple and convenient, the preparation conditions are easy to obtain and control, the prepared zinc ferrite/cadmium sulfide nanosphere composite visible-light-driven photocatalyst is a green pollution-free high-performance catalyst, the photocatalytic activity is high, the degradation time is short, the effect is good, the magnetism is realized, the separation is easy, and the potential application prospect is realized.

drawings

FIG. 1 is an X-ray diffraction diagram of a zinc ferrite-cadmium sulfide nanosphere composite visible light photocatalyst prepared in examples 1-4 of the present invention;

FIG. 2 is a scanning electron microscope image of the zinc ferrite-cadmium sulfide nanosphere composite visible light photocatalyst prepared in example 2 of the present invention;

FIG. 3 is a transmission electron microscope image of the zinc ferrite-cadmium sulfide nanosphere composite visible light photocatalyst prepared in example 2 of the present invention;

FIG. 4 is a graph showing the degradation effect of the zinc ferrite-cadmium sulfide nanosphere composite visible light photocatalyst prepared in examples 1-4 of the present invention; the vertical axis thereof is the concentration ratio C_t/C₀And represents the ratio of the residual concentration of malachite green to the initial concentration in the solution at the time of sampling.

Detailed Description

The invention will now be further illustrated by reference to specific examples, which are intended to be illustrative of the invention and are not intended to be a further limitation of the invention.