CN1792437A

CN1792437A - Method for loading silver nanometer particles onto nanometer titanium dioxide

Info

Publication number: CN1792437A
Application number: CN 200510126613
Authority: CN
Inventors: 林昌健; 陈艺聪; 庄惠芳; 孙岚
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2005-12-02
Filing date: 2005-12-02
Publication date: 2006-06-28
Anticipated expiration: 2025-12-02
Also published as: CN1318133C

Abstract

A process for carrying Ag nano-particles by TiO2 nano-tube and TiO2 nano-belt includes such steps as mixing absolute alcohol with n-tetrabutyl titanate and ethyl acetylacetate, adding distilled water and the alcohol solution of AgNO3, drying to obtain gel, grinding, calcining, adding aqueous solution of NaOH, ultrasonic dispersing, hydrothermel reaction, filtering, washing and drying.

Description

The method of loading silver nanometer particles onto nanometer titanium dioxide

Technical field

The present invention relates to a kind of nano titanic oxide catalyst preparation method, especially relate to a kind of method that combines by sol-gel (sol-gel) and hydrothermal treatment consists, at titanium dioxide (TiO ₂) nanotube and TiO ₂The method of nanometer bringing onto load silver (Ag) nano particle.

Background technology

Nano-TiO ₂Because its photocatalytic activity height, stability is good, and is pollution-free and cheap, has very wide application prospect in photocatalysis and optics field.Particularly caliber is about 10nm, the TiO of opening hollow ₂Nanotube has high-specific surface area (200～400m ²/ g) (Chien-Cheng Tsai and Hsisheng Teng; Chem.Mater.2004,16,4352-4358) embed ability (Xiaoming Sun and Yadong Li with very strong ion-exchange or nano particle; Chem.Eur.J.2003,9,2229-2238) because nano-TiO ₂The limit of itself is difficult to satisfy the requirement of various light-catalyzed reactions.Therefore, at nano-TiO ₂Last carried noble metal becomes current active subject to improve its photocatalytic activity.Studies show that noble metal-nano-TiO ₂Compound system can improve catalytic activity (Gang, L. separately effectively; Anderson, B.G.; Appl.Catal., B2002,40,101.), when the load capacity of noble metal fixedly the time, if its decentralization is high more, the also high more (SattlerML of activity of such catalysts then; Ross P N; Ultramicroscopy, 1986,20,21).

TiO ₂The method of nanoparticle surface depositing noble metal is a lot, mainly contains light deposition, electronation and high-temperature calcination three classes at present.(1) the light deposition method is directly to adopt the illumination of different wave length to penetrate, and precious metal salt is decomposed be deposited on TiO ₂Surface deposition (Sze Chi Chan and Mark A.Barteau; Langmuir; 2005,21,5588-5595); (2) chemical reduction method is by the reduction of weak base dipping (Wen BM, Liu CY, Liu Y; J.Phys.Chem.B, 2005,109:12372-12375) or method (Chandrasekharan, the N. of reducing agent reduction; Kamat, P.V.; J.Phys.Chem.B; 2000,104,10851) depositing noble metal; (3) high-temperature calcination is by slaine calcining and decomposing at high temperature, makes it at TiO ₂Surface deposition (Baifu Xin, Liqiang Jing; J.Phys.Chem.B 2005,109,2805-2809).Yet about TiO ₂The bibliographical information of nanotube, nanometer bringing onto load noble metal nano particles is few, and normally prepares nanotube or nanometer band earlier, and the method that adopts electronation then is at its surface deposition (Renzhi Ma, Takayoshi Sasaki; J.AM.CHEM.SOC.; 2004,126,10382-10388).Though these class methods can realize that metal nanoparticle is at TiO ₂The load on surface, but method is loaded down with trivial details, and reaction condition is required relatively strictness, the cost height, and load factor is lower usually.

Summary of the invention

The objective of the invention is at existing at nano-TiO ₂Problems such as the method for last loaded Ag nano particle is comparatively loaded down with trivial details, and reaction condition is had relatively high expectations, and load factor is lower, provide a kind of can be at different nano-TiOs ₂The new method of loaded Ag nano particle in the structure.

Step of the present invention is:

1) the positive four fourth fat of metatitanic acid and the 10～100ml acetoacetate second fat (EAcAc) of pressing absolute ethyl alcohol adding 50～500ml of every 1L mixes, and adds 10～50ml distilled water again, gets yellow transparent colloidal sol;

2) yellow sol by every 1L adds 1L AgNO respectively ₃Ethanolic solution (AgNO wherein ₃Be 1～50g), be dried to gel, grind then, 400～800 ℃ of calcinings, the TiO of the Ag nano particle that must mix ₂Nano particle;

3) add the TiO of 1～50g doping Ag by the 10mol/L NaOH aqueous solution of every 1L ₂Nano particle after the ultrasonic dispersion, changes in the water heating kettle, and hydro-thermal reaction 12～72h respectively under 120～200 ℃ of temperature, product spend after the deionised water dry after filtration.

In step 2) in, add 1L AgNO respectively by the colloidal sol of every 1L ₃Ethanolic solution (contains AgNO ₃Be 1～50g), stir 1～10h,, grind after being dried to gel then at 60 ℃ of constant temperature of constant temperature air dry oven.At 400～800 ℃ of calcining 0.5～8h, can make the TiO of doping Ag nano particle ₂Nano particle.

The present invention not only can realize equably at TiO ₂Loaded Ag nano particle on nanotube and the nanometer band, controlled (the diameter 2～10nm) of the particle diameter of nano particle, the decentralization height, uniform particles, it is narrow to distribute, and load capacity is controlled, and has that technology is simple, operability and highly versatile, is suitable for advantages such as large-scale production, equipment needed thereby is simple and easy, and be expected to further develop and become high performance catalyst and other specific function material, in many high-tech areas important use is arranged.

Description of drawings

The TiO that Fig. 1 (a, b) makes for the present invention ₂The transmission electron microscope photo of nano tube supported Ag nano particle product (implementation condition is seen embodiment 1).As seen from Figure 1, the Ag nano particle is evenly distributed, its particle size average out to 5nm.

Fig. 2 is the EDAX results (EDS) of product chemical composition.By the result as can be known, at the silver-colored content quite high (load factor is 19%) (signal of copper comes from copper mesh in Fig. 2) in surface.

Fig. 3 is the result (XPS) of the photoelectron spectroscopy of the nano particle of silver in the prepared product.By result TiO as can be known ₂Nano tube supported Nano silver grain valence state is a zeroth order, and what institute's load was described is the fine silver particle.

Fig. 4 (a, b) is TiO ₂The transmission electron microscope photo (implementation condition is seen embodiment 2) of nanometer bringing onto load Nano silver grain product.Its particle size average out to of more uniform as seen from Figure 4 Ag nano particle 2nm.

The specific embodiment

The present invention is further illustrated below in conjunction with embodiment.

Embodiment 1: employing adds 0.5ml EAcAc earlier in the 30ml absolute ethyl alcohol under normal temperature and normal pressure, under agitation add positive four butyl esters of 3mL metatitanic acid, behind the reaction 1h, adds 0.3ml distilled water in 10min, and it is stand-by to get yellow transparent colloidal sol.In glassy yelloe colloidal sol, add the 0.2g silver nitrate then, continue to stir 3h,, be dried to gel, grind then at 60 ℃ of constant temperature of constant temperature air dry oven.At 450 ℃ of calcining 2h, make the TiO of doping Ag nano particle ₂Nano particle.With doped Ti O ₂Nano particle adds the 30ml 10M NaOH aqueous solution, and at room temperature ultrasonic dispersion changes in the water heating kettle after waiting to be uniformly dispersed, difference hydro-thermal reaction 48h under 120 ℃ of temperature, and product washs with deionized water and watery hydrochloric acid, after filtration at 80 ℃ of dry 6h.

Embodiment 2: employing adds 0.5ml EAcAc earlier in the 30ml absolute ethyl alcohol under normal temperature and normal pressure, under agitation add positive four butyl esters of 3mL metatitanic acid, behind the reaction 1h, adds 0.3ml water in 10min, and it is stand-by to get yellow transparent colloidal sol.In glassy yelloe colloidal sol, add the 0.1g silver nitrate then, continue to stir 3h,, be dried to gel, grind then,, make the TiO of doping Ag nano particle at 450 ℃ of calcining 2h at 60 ℃ of constant temperature of constant temperature air dry oven ₂Nano particle.And with doped Ti O ₂Nano particle adds the 30ml 5M NaOH aqueous solution, and at room temperature ultrasonic dispersion changes in the water heating kettle after waiting to be uniformly dispersed, difference hydro-thermal reaction 48h under 120 ℃ of temperature, and product washs with deionized water and watery hydrochloric acid, after filtration at 80 ℃ of dry 6h.

Embodiment 3-5 adopts to add 0.5ml EAcAc earlier under normal temperature and normal pressure in the 30ml absolute ethyl alcohol, under agitation adds the 3mL butyl titanate, behind the reaction 1h, in 10min, adds 0.3ml water, and is stand-by.Change preparation parameter, specifically as shown in table 1.

The different preparation parameters of table 1. (embodiment 1-5) obtain different Ag load TiO ₂Nanotube and nanometer band

Embodiment	The amount (g) that adds silver nitrate	Calcining heat (℃)	Calcination time (h)	NaOH concentration (mol/L)	Hydrothermal temperature (℃)	TiO ₂Pattern	Ag load factor (%)	Ag average-size (nm)
Embodiment	The amount (g) that adds silver nitrate	Calcining heat (℃)	Calcination time (h)	NaOH concentration (mol/L)	Hydrothermal temperature (℃)	TiO ₂Pattern	Ag load factor (%)	Ag average-size (nm)	1	0.2	450	2	10	120	Nanotube	19	5
2	0.1	450	2	5	120	The nanometer band	9	2	1	0.2	450	2	10	120	Nanotube	19	5
2	0.1	450	2	5	120	The nanometer band	9	2	3	0.5	400	4	5	200	The nanometer band	42	10
4	1	450	2	5	200	The nanometer band	71	19	3	0.5	400	4	5	200	The nanometer band	42	10
4	1	450	2	5	200	The nanometer band	71	19	5	0.05	800	2	10	130	Nanotube	5	8

Claims

1, the method for loading silver nanometer particles onto nanometer titanium dioxide is characterized in that the steps include:

1) the positive four fourth fat of metatitanic acid and the 10～100ml acetoacetate second fat of pressing absolute ethyl alcohol adding 50～500ml of every 1L mixes, and adds 10～50ml distilled water again, gets yellow transparent colloidal sol;

2) yellow sol by every 1L adds 1L AgNO respectively ₃Ethanolic solution, wherein AgNO ₃Be 1～50g, be dried to gel, grind then, 400～800 ℃ of calcinings, the TiO of the Ag nano particle that must mix ₂Nano particle;

2, the method for loading silver nanometer particles onto nanometer titanium dioxide as claimed in claim 1 is characterized in that in step 2) in, add 1L AgNO respectively by the colloidal sol of every 1L ₃Ethanolic solution stirs 1～10h, then at 60 ℃ of constant temperature of constant temperature air dry oven, grinds after being dried to gel.

3, the method for loading silver nanometer particles onto nanometer titanium dioxide as claimed in claim 1 is characterized in that in step 2) in, calcination time is 0.5～8h.