CN103721714A - Preparation method of Fe3O4/TiO2 composite - Google Patents

Abstract

The invention provides a preparation method of a Fe3O4/TiO2 composite and belongs to the field of nano materials. The preparation method comprises the following steps: (1), FeCl2*4H2O and FeCl3*6H2O are weighed, dissolved in water and adjusted by ammonium hydroxide until pH reaches 11, a citric acid solution is added, stirring is performed for 30 min at a room temperature, crystallization is performed for 30 min under water bath stirring at the temperature of 80 DEG C, ultrasonic dispersion is performed for 20 min, and a large quantity of black Fe3O4 particles are generated, subjected to separation by a strong magnet and dried to obtain Fe3O4 ultra-fine powder; and (2), appropriate polyethylene glycol is added into the Fe3O4 ultra-fine powder with stirring, a titanous sulfate solution is added, the molar ratio of Fe3O4 to titanous sulfate is (10-20):1, a urea solution is added, the pH value is adjusted to be 2.0-3.5, a large quantity of brown particles are generated through a reaction for 3-5 h under water bath at the temperature of 80 DEG C, and the Fe3O4/TiO2 composite is obtained. According to the preparation method, Fe3O4 is coated with TiO2, so that a TiO2 recovery problem can be solved well, furthermore, micro Fe<3+> decomposed in the preparation process reduces the band gap of TiO2 effectively, an absorption wavelength coverage of a semiconductor can be expanded to a visible light range, and the visible light photocatalytic activity of TiO2 is enhanced.

Description

A kind of Fe 3o 4/ TiO 2the preparation method of composite

 

Technical field

The invention belongs to field of nanometer material technology, particularly a kind of Fe ₃o ₄/ T iO ₂the preparation method of composite.

 

Background technology

Nano titanium oxide is a kind of transparency material that has shielding ultraviolet rays function and produce colour effect.High unity due to its transparency and anti-ultraviolet function, makes it once appearance, just in many-sides such as sun-proof skin care, plastic membrane product, woodenware protection, transparent durable finish paint, fine ceramics, is applied widely.Particularly in the latter stage eighties, after this effect pigment that can produce tempting " changeable colors along with angle " effect is successfully used to limo finish paint, caused worldwide common concern, developed country is as U.S., day, Ou Deng state is very active to this research work, a large amount of manpowers have in succession been dropped into, material resources, and worked out long-term plan, in competition in the international market fierceness so far, they have obtained many amazing achievements, and formed high-tech nanometer material industry, produce the high high function fine inorganic material of this added value, receive good economic benefit and social benefit, nanometer oxide material is also just becoming the focus that China's Industry circle is paid close attention to.At present, the method for preparing nano TiO 2 is a lot, substantially can be summarized as Physical and chemical method.Physical is called again mechanical crushing method, to disintegrating apparatus, requires very high; Chemical method can be divided into again vapor phase method (CVD), liquid phase method and solid phase method.The nano-TiO that adopts said method to prepare ₂granularity is less, and use procedure is easily run off.

 

Summary of the invention

The invention provides a kind of Fe ₃o ₄/ T iO ₂the preparation method of composite, T iO ₂be coated on Fe ₃o ₄outside just can well solve T iO ₂the problem reclaiming,

A kind of Fe of the present invention ₃o ₄/ T iO ₂the preparation method of composite, carries out according to following steps:

(1) according to the mol ratio of ferrous and molysite, be (0.2 ~ 1): 1 takes FeC l ₂.4H ₂o and FeC l ₃. 6H ₂o is also dissolved in water, regulates until pH=11, then add citric acid solution with ammoniacal liquor, and 30m at room temperature stirs in above suspension liquid system, crystallization 30m under 80 ℃ of stirring in water bath, and ultrasonic dispersion 20m in. generates the Fe of a large amount of black ₃o ₄particle, separated with strong magnet, the dry Fe that obtains ₃o ₄ultramicro-powder;

(2) under the speed of 1 000 r/m in stirs to Fe ₃o ₄ultramicro-powder adds appropriate polyethylene glycol, then adds titanium sulfate solution, Fe ₃o ₄with the mol ratio of titanium sulfate be (10 ~ 20): 1, add urea liquid, adjusting pH value is to react 3 ~ 5 h under 2.0 ~ 3.5,80 ℃ of water-baths, generates a large amount of brown particles, with the separated also cyclic washing of strong magnet, obtains Fe ₃o ₄/ T iO ₂composite.

The present invention can prepare the nano-magnetic Fe that particle diameter is the spinel structure of 14 ~ 20 nm ₃o ₄and product has higher purity .VSM result and shows that coercivity H is that 1 Oe, remanent magnetization M r are 4183 emu/g, saturation magnetization M s is 48102 emu/g, and coercivity and remanent magnetization are relatively little, can think that this sample has superparamagnetism.

The present invention is T iO ₂be coated on Fe ₃o ₄outside just can well solve T iO ₂the problem reclaiming, and the micro Fe 3+ decomposing in preparation process effectively reduces T iO ₂energy gap, make semi-conductive absorbing wavelength scope extend to visible region, strengthened T iO ₂visible light photocatalysis active. utilize sluggish precipitation can prepare the Fe of double seal structure ₃o ₄/ T iO ₂compound particle, T iO ₂be wrapped in equably Fe ₃o ₄outside, there is red shift by a relatively large margin in the optical absorption band of this composite particles, and enter visible region, absorb luminous intensity also obviously increases simultaneously. this composite also have be easy to reclaim, working condition is less demanding, low cost and other advantages, is hopeful to be applied to the industrialization of visible light catalyst.

 

The specific embodiment

embodiment 1

A kind of Fe ₃o ₄/ T iO ₂the preparation method of composite, carries out according to following steps:

(1) according to the mol ratio of ferrous and molysite, be that 0.2:1 takes FeC l ₂.4H ₂o and FeC l ₃. 6H ₂o is also dissolved in water, regulates until pH=11, then add citric acid solution with ammoniacal liquor, and 30m at room temperature stirs in above suspension liquid system, crystallization 30m under 80 ℃ of stirring in water bath, and ultrasonic dispersion 20m in. generates the Fe of a large amount of black ₃o ₄particle, separated with strong magnet, the dry Fe that obtains ₃o ₄ultramicro-powder.

(2) under the speed of 1 000 r/m in stirs to Fe ₃o ₄ultramicro-powder adds appropriate polyethylene glycol, then adds titanium sulfate solution, Fe ₃o ₄with the mol ratio of titanium sulfate be (10 ~ 20): 1, add urea liquid, adjusting pH value is under 2.0 ~ 3.5,80 ℃ of water-baths, to react 3 ~ 5 h. to generate a large amount of brown particles, with the separated also cyclic washing of strong magnet, obtains Fe ₃o ₄/ T iO ₂composite.

Preparing after testing particle diameter is the nano-magnetic Fe of the spinel structure of 14 ~ 20 nm ₃o ₄and product has higher purity .VSM result and shows that coercivity H is that 1 Oe, remanent magnetization M r are 4183 emu/g, saturation magnetization M s is 48102 emu/g, and coercivity and remanent magnetization are relatively little, can think that this sample has superparamagnetism.

T iO ₂be coated on Fe ₃o ₄outside just can well solve T iO ₂the problem reclaiming, and the micro Fe 3+ decomposing in preparation process effectively reduces T iO ₂energy gap, make semi-conductive absorbing wavelength scope extend to visible region, strengthened T iO ₂visible light photocatalysis active.

embodiment 2

A kind of Fe ₃o ₄/ T iO ₂the preparation method of composite, carries out according to following steps:

(1) according to the mol ratio of ferrous and molysite, be that 1:1 takes FeC l ₂.4H ₂o and FeC l ₃. 6H ₂o is also dissolved in water, regulates until pH=11, then add citric acid solution with ammoniacal liquor, and 30m at room temperature stirs in above suspension liquid system, crystallization 30m under 80 ℃ of stirring in water bath, and ultrasonic dispersion 20m in. generates the Fe of a large amount of black ₃o ₄particle, separated with strong magnet, the dry Fe that obtains ₃o ₄ultramicro-powder.

(2) under the speed of 1 000 r/m in stirs to Fe ₃o ₄ultramicro-powder adds appropriate polyethylene glycol, then adds titanium sulfate solution, Fe ₃o ₄with the mol ratio of titanium sulfate be 20:1, add urea liquid, adjusting pH value is under 2.0 ~ 3.5,80 ℃ of water-baths, to react 3 ~ 5 h. to generate a large amount of brown particles, with the separated also cyclic washing of strong magnet, obtains Fe ₃o ₄/ T iO ₂composite.

Preparing after testing particle diameter is the nano-magnetic Fe of the spinel structure of 14 ~ 20 nm ₃o ₄and product has higher purity .VSM result and shows that coercivity H is that 1 Oe, remanent magnetization M r are 4183 emu/g, saturation magnetization M s is 48102 emu/g, and coercivity and remanent magnetization are relatively little, can think that this sample has superparamagnetism.

T iO ₂be coated on Fe ₃o ₄outside just can well solve T iO ₂the problem reclaiming, and the micro Fe 3+ decomposing in preparation process effectively reduces T iO ₂energy gap, make semi-conductive absorbing wavelength scope extend to visible region, strengthened T iO ₂visible light photocatalysis active.

Claims (1)

1. a Fe ₃o ₄/ T iO ₂the preparation method of composite, is characterized in that carrying out according to following steps:

(1) according to the mol ratio of ferrous and molysite, be (0.2 ~ 1): 1 takes FeC l ₂.4H ₂o and FeC l ₃. 6H ₂o is also dissolved in water, regulates until pH=11, then add citric acid solution with ammoniacal liquor, and 30m at room temperature stirs in above suspension liquid system, crystallization 30m under 80 ℃ of stirring in water bath, and ultrasonic dispersion 20m in. generates the Fe of a large amount of black ₃o ₄particle, separated with strong magnet, the dry Fe that obtains ₃o ₄ultramicro-powder;

(2) under the speed of 1 000 r/m in stirs to Fe ₃o ₄ultramicro-powder adds appropriate polyethylene glycol, then adds titanium sulfate solution, Fe ₃o ₄with the mol ratio of titanium sulfate be (10 ~ 20): 1, add urea liquid, adjusting pH value is to react 3 ~ 5 h under 2.0 ~ 3.5,80 ℃ of water-baths, generates a large amount of brown particles, with the separated also cyclic washing of strong magnet, obtains Fe ₃o ₄/ T iO ₂composite.