CN105126873A - Preparation method of photo-catalyst nano CdS/kaolin composite material - Google Patents

Abstract

The invention discloses a preparation method of a photo-catalyst nano CdS/kaolin composite material. In the invention, a nano CdS photo-catalyst is immobilized on surface of kaolin to prepare the CdS/kaolin composite material. The preparation method includes the steps of preparation of a reaction liquid, synthetic reaction, washing and drying. The reaction liquid is prepared according to the mass ratio of CdCl2.2.5H2O:PEG:water=4.0:(0.60-0.70):(11.0-12.0):(45-55). Reaction materials in the synthetic reaction is prepared according to the mass ratio of Na2S.9H2O:CdCl2.2.5H2O=1:(1.0-1.2). When the synthetic reaction is finished, the product is washed and dried to obtain the kaolin-supported CdS being 11.1-75% in ratio. The preparation method is simple in process, is low in cost and is good in product quality and performance.

Description

The preparation method of photochemical catalyst nano-tube/CdS/kaolin composite material

Technical field

The present invention relates to the preparation method of the composite photocatalyst for wastewater treatment, be specifically related to the preparation method of photochemical catalyst nano-tube/CdS/kaolin composite material.

Background technology

" photocatalysis " this term inherently means the combination of both photochemistry and catalyst, and therefore light and catalyst are the necessary conditions causing and promote photocatalysis oxidation reaction.At present, photocatalysis progressively forms an independently research field with its distinctive simplification, wherein in raising electricity conversion, maximization light degradation property, expansion semiconductor light response range and photochemical catalyst recovery, cause the research enthusiasm of researcher greatly, especially from Photocatalytic Oxidation With Semiconductors method for the treatment of since organic pollutants, be more and more subject to people's attention.

Semiconductor light-catalyst common at present has TiO ₂, ZnO, CdS etc., wherein nano-TiO ₂semiconductor light-catalyst is nontoxic with it, catalytic activity is high, oxidability is strong and the advantage such as good stability, is subject to people's common concern.In practical application and experimental study, TiO ₂adopt floating type and support type, supported titanium ₂catalysis material, with single TiO ₂suspension system is compared, and has easy recovery, and the advantage such as to reuse, and becomes the focus of current catalysis material research field.But nano-TiO ₂the problem that complex manufacturing, cost are high constrains its application in industrialization.

Summary of the invention

The object of this invention is to provide the preparation method of photochemical catalyst nano-tube/CdS/kaolin composite material that a kind of production technique is simple, cost is low, product quality performance is good.

For realizing above object, nano-tube/CdS photochemical catalyst is fixed to kaolin surface and obtains CdS/ kaolin composite material by the preparation method of photochemical catalyst nano-tube/CdS/kaolin composite material of the present invention, and operating procedure is as follows:

Prepared by the first step, reactant liquor: by kaolin and CdCl ₂2.5H ₂o is even by magnetic stirrer in water; Add as being dissolved to evenly in the Surfactant PEG preventing nano material from reuniting to reactant liquor; Kaolin, CdCl ₂2.5H ₂the additional proportion of O, PEG and water is kaolin: CdCl in mass ratio ₂2.5H ₂: (11.0-12.0): (45-55) O:PEG: water=4.0:(0.60-0.70);

Second step, synthetic reaction: by Na ₂s9H ₂o adding distil water dissolves, and at room temperature dropwise add, in dropping process, solution becomes light yellow suspension by colorless cleared solution gradually and finally becomes orange suspension, dropwises rear heated at constant temperature reaction (25-35min) min; Na ₂s9H ₂the additional proportion of O is Na ₂s9H ₂o:CdCl ₂2.5H ₂o=1:(1.0-1.2);

3rd step, washing: be separated by suspension whizzer, remove supernatant liquid, fully wash remaining solid by absolute ethyl alcohol and deionized water respectively, to remove dispersant in solid and other foreign ions;

4th step, drying: by the dry 1-2h at 100-120 DEG C in drying box of the solid after washing, the ratio of obtaining is the kaoline loaded cadmium sulfide of 11.1%-75%.

The present invention is based on following theoretical principle:

CdS is typical II-VI race's semiconductor, and when CdS particle reaches the Bohr radius of nanoscale close to exciton, optical energy gap can change a lot, so very large skew occurs the absorption threshold value of light, produces very strong exciton effect.Due to the effect of skin effect and quantum size effect, the optics of particle, great changes will take place for the character such as electricity and nonlinear optics, make it have superior light transfer characteristic and luminescent properties, thus have broad application prospects in fields such as luminescent material, photocatalysis, opto-electronic devices.

The energy gap of nano-tube/CdS is narrower (2.42eV), absorbs the wide and tool advantage of the wave-length coverage of sunshine.Simultaneously nano-tube/CdS has the advantages such as preparation is easy, cheap, specific area is large, Active sites is many, can organic pollution well in degradation water, has report when its application study is at home and abroad on document.But nano-tube/CdS is easily reunited in its preparation process, cause its size larger.In addition, although suspended state photochemical catalyst specific area is large, reactivity is good, there is easily cohesion and the difficult shortcoming such as to be separated, thus limits the practical application of photocatalysis technology.Solve easily cohesion, nano-tube/CdS is fixed on carrier by the difficult good way of one be separated exactly.

Kaolinic main component, its crystal structure is made up of-Si-O tetrahedral layer and-Al-(O, OH) octahedral layer, and share the standard two dimension lamella that oxygen atom height of formation is orderly between tetrahedron and octahedron, it has larger specific area.Kaolinite lamella negatively charged, positively charged ion and particulate in energy adsorbed water, be widely used in the process of various waste water.

The preparation method of above-mentioned photochemical catalyst nano-tube/CdS/kaolin composite material has following characteristics and beneficial effect:

The present invention prepares CdS/ kaolin composite material by nano-tube/CdS photochemical catalyst is fixed to kaolin surface, absorption and photocatalysis technology are combined, advanced treating can be carried out on the one hand to organic wastewater, provide a kind of nano-tube/CdS/kaolin composite material integrating absorption property and Photocatalytic Degradation Property, for organic industrial sewage process aspect provides new method; Be convenient to the recycling of composite on the other hand.

Accompanying drawing explanation

Fig. 1 is composite SEM shape appearance figure prepared by the preparation method of photochemical catalyst of the present invention nano-tube/CdS/kaolin composite material.

Fig. 2 is the XRD figure of the different CdS content of composite prepared by the preparation method of photochemical catalyst of the present invention nano-tube/CdS/kaolin composite material.

Detailed description of the invention

Below in conjunction with the drawings and specific embodiments, the preparation method to photochemical catalyst nano-tube/CdS/kaolin composite material of the present invention is described in further detail.

embodiment 1

Preparation method's operating procedure of photochemical catalyst nano-tube/CdS/kaolin composite material of the present invention is as follows:

Prepared by the first step, reactant liquor: take 4.0g kaolin, in 50mL water, add 0.64gCdCl ₂2.5H ₂o, magnetic stirring apparatus stirs; Measuring 10mLPEG and adding in reactant liquor is dissolved to evenly;

Second step, synthetic reaction: take 0.85gNa ₂s9H ₂o, adding distil water dissolves, and at room temperature dropwise add, in dropping process, solution becomes light yellow suspension by colorless cleared solution gradually and finally becomes orange suspension, dropwises rear heated at constant temperature reaction 30min;

3rd step, washing: be separated by suspension whizzer, remove supernatant liquid, respectively with absolute ethyl alcohol and deionized water washing remaining solid 3 times, to remove dispersant in solid and other foreign ions;

4th step, drying: by the dry 2h at 120 DEG C in drying box of the solid after washing, the ratio of obtaining is the kaoline loaded cadmium sulfide of 11.1%.

embodiment 2

By CdCl ₂2.5H ₂o quantity changes 1.3g, Na into ₂s9H ₂o changes 1.7g into, and other parameters and operating procedure, with embodiment 1, obtain 20% kaoline loaded cadmium sulfide.

embodiment 3

By CdCl ₂2.5H ₂o quantity changes 3.2g, Na into ₂s9H ₂o changes 4.2g into, and other parameters and operating procedure, with embodiment 1, obtain 38.5% kaoline loaded cadmium sulfide.

embodiment 4

By CdCl ₂2.5H ₂o quantity changes 5.1g, Na into ₂s9H ₂o changes 6.7g into, and other parameters and operating procedure, with embodiment 1, obtain 50% kaoline loaded cadmium sulfide.

embodiment 5

By CdCl ₂2.5H ₂o quantity changes 10.2 into, Na ₂s9H ₂o changes 13.6g into, and other parameters and operating procedure are with embodiment 1, and obtained ratio is the kaoline loaded cadmium sulfide of 75%.

Fig. 1 Electronic Speculum pattern shows: show that the sulfur loaded cadmium that obtained by the present invention in the form of sheets, and distribution is relatively more even, and surface is comparatively coarse, is easy to be adsorbed with organic dye etc.

Fig. 2 XRD figure shows: the position that the kaoline loaded cadmium sulfide ratio that above-described embodiment 1-embodiment 5 obtains is respectively the peak of 11.1%, 20%, 38.5%, 50%, 75% overlaps substantially, illustrate that the composition of various composite is identical, only content is different.

Claims (1)

1. a preparation method for photochemical catalyst nano-tube/CdS/kaolin composite material, is characterized in that: nano-tube/CdS photochemical catalyst is fixed to kaolin surface and obtains CdS/ kaolin composite material, operating procedure is as follows:

Prepared by the first step, reactant liquor: by kaolin and CdCl ₂2.5H ₂o is even by magnetic stirrer in water; Add as being dissolved to evenly in the Surfactant PEG preventing nano material from reuniting to reactant liquor; Kaolin, CdCl ₂2.5H ₂the additional proportion of O, PEG and water is kaolin: CdCl in mass ratio ₂2.5H ₂: (11.0-12.0): (45-55) O:PEG: water=4.0:(0.60-0.70);

Second step, synthetic reaction: by Na ₂s9H ₂o adding distil water dissolves, and at room temperature dropwise add, in dropping process, solution becomes light yellow suspension by colorless cleared solution gradually and finally becomes orange suspension, dropwises rear heated at constant temperature reaction (25-35min) min; Na ₂s9H ₂the additional proportion of O is Na ₂s9H ₂o:CdCl ₂2.5H ₂o=1:(1.0-1.2);

3rd step, washing: be separated by suspension whizzer, remove supernatant liquid, fully wash remaining solid by absolute ethyl alcohol and deionized water respectively, to remove dispersant in solid and other foreign ions;

4th step, drying: by the dry 1-2h at 100-120 DEG C in drying box of the solid after washing, the ratio of obtaining is the kaoline loaded cadmium sulfide of 11.1%-75%.