CN104815696A

CN104815696A - Metal oxalate nanofiber and preparation method as well as application thereof

Info

Publication number: CN104815696A
Application number: CN201510178383.6A
Authority: CN
Inventors: 申益; 张智珲; 肖凯军
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2015-04-15
Filing date: 2015-04-15
Publication date: 2015-08-05
Anticipated expiration: 2035-04-15
Also published as: CN104815696B

Abstract

The invention discloses a preparation method of a metal oxalate nanofiber. The method comprises the following steps: dissolving metal salt solution in ethanol solution to prepare solution A to serve as metal precursor, wherein the metal salt comprises at least one metal element, cobalt; dissolving oxalic acid in the ethanol solution to prepare solution B, then titrating the solution B in the solution A under magnetic stirring, stirring for 20-50 minutes, transferring obtained suspension in a high-pressure sterilizer, storing at 100-200 DEG C for 12-48 hours, cooling to room temperature, washing the finally obtained product with de-ionized water and drying at 50-100 DEG C to obtain the metal oxalate nanofiber. The preparation method has the advantages of simple preparation process, low cost, easiness in control of preparation conditions, short synthesis period and the like. The prepared metal oxalate nanofiber has a superior degradation effect to congo red dye in a hydrogen peroxide system as a catalyst, and the water quality purification effect can be obviously improved.

Description

A kind of metal oxalate nanofiber and its preparation method and application

Technical field

The present invention relates to the research of congo red in a kind of preparation method of novel metal oxalates material and degradation water thereof, belong to water treatment field.

Background technology

Waste water from dyestuff is the chief component of printing weaving chemical engineering industry waste water, in the last few years, along with developing rapidly of dyestuff and printing and dyeing industry, new additive, dyestuff is in the extensive use of printing and dyeing chemical engineering industry, its waste water produced is on the rise to environmental hazard, increasing toxic organic compound has been it is found that in waste water, some organic matter even can cause gene mutation, canceration, heavy metal slow poisoning, and waste water from dyestuff is discharged to rivers, ocean and surface water, even if dye component concentration is wherein very low, also the light transmittance being discharged into water body can be caused to reduce, water ecosystem is caused to destroy, severe contamination is caused to environment, and then affect the Health and Living of the mankind.And Congo red be purposes one of dyestuff more widely, its turnover rate in production and use procedure is high, and than being easier to enter water body, damages environment; Congo red is diphenyl amine azo dyes, chemical name is diphenyl-4,4 '-two (azo-2-)-1-amino naphthalenes-4-sodium sulfonate, due to the stability of its structure, its waste water from dyestuff produced is difficult to by traditional physics, chemistry, biological method degraded, although these methods can make congo red waste water color fade, its intermediate product produced can not be degraded effectively, and its environmental pollution is larger.

Summary of the invention

The oxalates composite metal catalyst material that the object of the present invention is to provide a kind of high degradation rate, degradation time fast and the process approach in dye wastewater treatment thereof, this material shows good effect when degrading congo red waste water.

Object of the present invention is achieved through the following technical solutions:

A preparation method for metal oxalate nanofiber, comprises the following steps:

Be dissolved in by metal salt solution in ethanolic solution, be made into solution A, as metal precursor, described slaine is at least containing a kind of metallic element of cobalt; Again oxalic acid is dissolved in ethanolic solution, be made into B solution, then by B solution under magnetic stirring titration in solution A, stir 20-50min, the suspension of gained is transferred in autoclave, preserves 12-48h, is cooled to room temperature for 100-200 DEG C, the product deionized water rinsing finally obtained is clean, and 50-100 DEG C of drying obtains metal oxalate nanofiber.

Described slaine is one or more the mixture in the nitrate of cobalt, copper, nickel and iron or sulfate.

Described slaine is nitrate or the sulfate of cobalt and copper two kinds of metals.

The mol ratio of described cobalt and copper is (1 ~ 10): 1.

The mol ratio of described cobalt and oxalic acid is 1:1.

In described solution A, the concentration of cobalt ions is 0.1 ~ 0.3mol/L, and the concentration of described B solution is 0.1-1.0mol/L.

Described metal oxalate nano material in hydrogen peroxide system for removing the pollutant in water.

Described pollutant is benzene class organic dyestuff.

Described organic dyestuff is Congo red, methyl orange, rhodamine B.

Compared with prior art, tool of the present invention has the following advantages:

(1) the present invention prepares cobalt copper weed silicate nanometer fiber and the cobalt oxalate nanofiber of high reaction activity by chemical coprecipitation, and this preparation technology is simple, cost is low, preparation condition is easy to advantages such as controlling, synthesis cycle is short.The metal oxalate nano material of preparation has excellent degradation effect to congo red as catalyst in hydrogen peroxide system.Effects of purification quality can be significantly improved.

(2) metal composite catalyst of oxalates is compared with metal oxide catalyst, and its catalytic degradation effect is more excellent.And composition metal has certain synergy in its course of reaction.The oxalates of compound shows the catalytic performance of comparative superiority.

Accompanying drawing explanation

The ESEM that Fig. 1 (a), (c) are cobalt oxalate and transmission electron microscope picture, the ESEM that (b), (d) are cobalt copper weed hydrochlorate and projection electron microscopic picture.

Fig. 2 is the N of cobalt copper weed hydrochlorate (a) and the cobalt oxalate (b) prepared under different pressures ₂adsorption-desorption curve.

Fig. 3 is the comparison diagram of different catalysts degraded congo red.

Fig. 4 is the catalytic degradation effect figure of material to congo red.

Fig. 5 is the catalytic degradation effect figure to congo red under different temperatures.

Detailed description of the invention

Below in conjunction with accompanying drawing, example of the present invention is more specifically described, but embodiments of the present invention are not limited thereto.

Embodiment 1

Get 2.5mmol Gerhardite and 7.5mmol Cobalt(II) nitrate hexahydrate, be dissolved in 40ml ethanol, gained solution is prepared into metal precursor A, get 7.5mmol oxalic acid again, be dissolved in 40ml ethanol, the solution be made into is B, then by solution B under magnetic stirring titration in solution A, stir 30min, the suspension of gained is transferred in autoclave, preserves 12h, is cooled to room temperature for 120 DEG C, the product deionized water rinsing finally obtained is clean, and 80 DEG C of dryings obtain cobalt copper weed hydrochlorate.The preparation method of cobalt oxalate is identical, does not just add Gerhardite in precursor solution.Its electron microscopic picture is as shown in Figure 1: (a), (c) and (b), (d) are respectively ESEM and the transmission electron microscope picture of cobalt oxalate and cobalt copper weed hydrochlorate, and prepared oxalates material all has nanometer fibrous.In Fig. 2, (a) and (b) is respectively the N of cobalt copper weed hydrochlorate and cobalt oxalate ₂adsorption-desorption curve.BET surface area is respectively 76m ²/ g and 74m ²/ g.

Above-mentioned obtained metal oxalate catalysis material is to the process of waste water from dyestuff:

Congo red is diphenyl amine azo dyes, is a kind of important dyestuff, and cobalt copper weed hydrochlorate, in hydrogen peroxide system, can produce a large amount of strong oxidizer hydroxyl radical free radicals (HO), Congo red dyestuff such as grade of can effectively degrading.It can be applied in water treatment as catalyst.

The cobalt copper weed hydrochlorate (or cobalt oxalate) of 100mg is added in the Congo red solution of 100ml mass concentration 100mg/L, add the hydrogenperoxide steam generator of 3% mass fraction again, stir, initial soln PH is regulated to be 7 with sulfuric acid and NaOH, temperature 30 DEG C, get a certain amount of solution, centrifugal, filter, then adopt its concentration of spectrophotometric determination, thus calculate this catalyst material to Congo red degradation rate, Fig. 3 is that different catalysts is to Congo red degradation curve, cobalt copper weed hydrochlorate behaves oneself best, and reaches 96.20%.Fig. 4 is the design sketch of cobalt copper weed hydrochlorate catalytic degradation congo red.

Embodiment 2

In the Congo red solution of catalytic degradation, change temperature 20 DEG C, preparation method and other catalytic condition are with embodiment 1.

Embodiment 3

In the Congo red solution of catalytic degradation, change temperature 40 DEG C, preparation method and other catalytic condition are with embodiment 1.

Embodiment 4

In the Congo red solution of catalytic degradation, change temperature 50 C, preparation method and other catalytic condition are with embodiment 1.

In embodiment 1,2,3,4, investigated the impact that differential responses temperature is Congo red on catalytic degradation, result as shown in Figure 5: the degradation rate corresponding to four temperature is respectively 96.20%, 63.70%, 96.33%, 97.60%.Along with the increase of reaction temperature, degradation effect is better, be because temperature raises, be that the decomposition of hydrogen peroxide significantly strengthens, create more strong oxidizer hydroxyl radical free radical (HO), make its more Congo red and intermediate product of degrading, after 100min, degradation speed is slack-off, may be because solution contains the elements such as a large amount of N, S, and the strong oxidizer produced can not degrade them effectively, so carry out the slower of contaminant degradation in solution along with the time.

Comparative example 1

The oxalates of the cobalt adopting distinct methods to prepare, it contrasts with the oxide of traditional iron, detects this oxalates material to the degradation effect of congo red.

As shown in Figure 3, oxalates metallic compound is as catalyst, and this material list reveals the catalytic effect good to congo red.

The present invention is the further improvement to class Fenton's reaction, and obtained the oxalates series of products of cobalt as catalyst, its catalytic degradation material is not only confined to metal oxide aspect, has widened the selection of material; And importantly this material is in water treatment, shows the degradation property to dyestuff excellence in water.

Above content is the explanation carried out in conjunction with concrete preferred embodiment; its material is not only only confined to the oxalates series of cobalt; under the prerequisite not departing from the design of this aspect, the metallic catalyst of oxalates series and metal oxalate catalytic degradation dyestuff all should be considered as belonging to the scope of protection of the invention.

Claims

1. a preparation method for metal oxalate nanofiber, is characterized in that, comprises the following steps:

2. preparation method according to claim 1, is characterized in that, described slaine is one or more the mixture in the nitrate of cobalt, copper, nickel and iron or sulfate.

3. preparation method according to claim 2, is characterized in that, described slaine is nitrate or the sulfate of cobalt and copper two kinds of metals.

4. preparation method according to claim 3, is characterized in that, the mol ratio of described cobalt and copper is (1 ~ 10): 1.

5. the preparation method according to claim 1 or 2 or 3 or 4, is characterized in that, the mol ratio of described cobalt and oxalic acid is 1:1.

6. the preparation method according to claim 1 or 2 or 3 or 4, it is characterized in that, in described solution A, the concentration of cobalt ions is 0.1 ~ 0.3mol/L, and the concentration of described B solution is 0.1-1.0mol/L.

7. the metal oxalate nanofiber prepared of method described in any one of claim 1 ~ 6.

8. the application of metal oxalate nanofiber described in claim 7, is characterized in that, this metal oxalate nanofiber in hydrogen peroxide system for removing the pollutant in water.

9. application according to claim 8, is characterized in that, described pollutant is benzene class organic dyestuff.

10. application according to claim 9, is characterized in that, described organic dyestuff is Congo red, methyl orange, rhodamine B.