CN103030168A

CN103030168A - Preparation method of spindle-shaped CeO2 microcrystal

Info

Publication number: CN103030168A
Application number: CN2012105741650A
Authority: CN
Inventors: 王芬; 周长江; 李承泽
Original assignee: Shaanxi University of Science and Technology
Current assignee: Shaanxi University of Science and Technology
Priority date: 2012-12-26
Filing date: 2012-12-26
Publication date: 2013-04-10

Abstract

The invention discloses a preparation method of a spindle-shaped CeO2 microcrystal, which comprises the steps of dissolving Ce(NO3)3.6H2O in deionized water to prepare a solution A, adding PEG6000 (polyethylene glycol 6000) and carbamide into the solution A, stirring continuously for 2h at 60DEG C to obtain a solution B, moving the uniformly stirred solution B into a reaction kettle, placing in an oven for reaction, conducting centrifugal washing after the reaction, drying, and obtaining the spindle-shaped CeO2 microcrystal. The spindle-shaped CeO2 microcrystal is synthesized in one step by taking PEG6000 as a feature control agent and adopting a hydrothermal method, and the spindle-shaped CeO2 microcrystal that is regular in feature and has average length about 15 micrometers is prepared by taking Ce(NO3)3.6H2O, PEG6000 (polyethylene glycol 6000), carbamide as raw materials and adopting the hydrothermal method. The method has the special advantages that the raw materials are relatively cheap; the cost is low; the productivity is greater; and the technological operation is simple. The method can be directly applicable to the preparation of doped and compound CeO2 powder.

Description

A kind of fusiformis CeO 2The preparation method of crystallite

Technical field

The invention belongs to technical field of ceramic material, be specifically related to a kind of fusiformis CeO ₂The preparation method of crystallite.

Background technology

CeO ₂It is the most common a kind of rare earth oxide oxide compound, because of its unique fluorite type structure and good redox property, be widely used in the aspects such as three-way catalyst, water-gas conversion, gas sensor, polishing material, hydrogen-storing material, uv-absorbing agent, photocatalyst and Solid Oxide Fuel Cell (SOFC).In three-way catalyst, CeO ₂As carrier, the nano particle of the metals such as Chang Yuyu Au, Ag, Pt, Cu is compound, provides active oxygen to nano metal when catalyzed reaction is carried out, and its vital role that plays is self-evident.CeO ₂As a kind of very important polishing material, it is simple to have a glossing, and the characteristics such as polishing velocity is fast, consumption is few, output is large are mainly used in the industries such as photoelectron, ornaments, building materials, grinding tool.CeO ₂The photoabsorption threshold values be 420nm, not only can absorbing ultraviolet, can also absorb a part of visible light, can improve its visible absorption scope by modification, and then improve photocatalysis efficiency.Because of Ce ³⁺With Ce ⁴⁺Between redox-potential lower, CeO ₂In have Ce ³⁺/ Ce ⁴⁺Oxidation reduction cycle also exists light activated catalytic oxidation when light-catalyzed reaction is carried out, so, CeO ₂Possessed the not available good characteristics of other single light-catalyzed reactions.Simultaneously, in these catalyzed reactions, catalytic activity also depends on pattern and the size of material.In addition, CeO ₂Stable performance, low price, toxicity is little, and excellent property more and more receives investigators' concern, in recent years particularly at CeO ₂And many effort have been made in composite material nanometer material preparation aspect.Qiu Kehui etc. adopt sol-gel (sol-gel) legal system for V take cerous nitrate, citric acid and ammonium meta-vanadate as raw material ⁵⁺Ion-doped nano CeO ₂Powder [Qiu Kehui, Zhang Wei, Li Junfeng, Wang Kejia .V ⁵⁺Synthetic and the sign [J] of ion-doped nano cerium oxide. China rare earth journal, 2009.4 (27,2): 209-212].But the powder reuniting of sol-gel method preparation is comparatively serious, and granularity is also larger, has affected its performance.Hongfeng Li etc. have prepared the CeO that Mn mixes by hydrothermal method ₂Many empty ball [Hongfeng Li, Guanzhong Lu, Qiguang Dai, Yanqin Wang, Yun Guo, Yanglong Guo.Efficient low-temperature catalytic combustion of trichloroethylene over flower-like mesoporous Mn-doped CeO ₂Microspheres[J] .Applied Catalysis B:Environmental, 2011 (102): 475-483].But hydro-thermal was for up to 5 days, and energy consumption is higher, is unfavorable for practical application.CHEN Feng etc. utilizes pollen to be template, has synthesized the flower-shaped CeO of many skies by techniques such as hydro-thermal, calcinings ₂Powder [CHENG Feng et al..Biogenic synthesis and catalysis of porous CeO ₂Hollow microspheres[J] .Journal of rare earths, 2012.4 (30,4): 350-354].But, the technique relative complex, particularly the calcining process energy consumption is higher.

Summary of the invention

The objective of the invention is to overcome the shortcoming of above-mentioned prior art, provide a kind of cost low, the simple to operate and fusiformis CeO that is easy to control ₂The preparation method of crystallite.

For achieving the above object, the technical solution used in the present invention is:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.01 ~ 0.05mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is (3 ~ 6): (0.5 ~ 2): 1 mol ratio adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 160 ~ 190 ℃ baking oven to react 10 ~ 20h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.

The present invention adopts hydrothermal method take PEG6000 as morphology control agent one-step synthesis fusiformis CeO ₂Crystallite is with Ce (NO ₃) ₃6H ₂O, PEG6000(polyethylene glycol 6000), urea is raw material, adopt hydrothermal method to prepare mean length and be about 15 μ m, the fusiformis CeO of pattern rule ₂Crystallite.The distinctive advantage of this method is that the relatively inexpensive cost of raw material is low, productive rate is large and technological operation is simple.The present invention can directly apply to and mix and compound CeO ₂In the preparation of powder.

Description of drawings

Fig. 1 is the fusiformis CeO of embodiment 1 preparation ₂The XRD diffractogram of crystallite;

Fig. 2 is the fusiformis CeO of embodiment 1 preparation ₂The stereoscan photograph of crystallite.

Embodiment

Embodiment 1:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.01mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is that the mol ratio of 5:1:1 adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 180 ℃ baking oven to react 15h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.

Fusiformis CeO with gained ₂Crystallite is measured with the Japanese Rigaku production D/Max-2200pc of company type X-ray diffractometer, and the result obtains preferably pure phase fusiformis CeO of crystallinity as shown in Figure 1 ₂Crystallite finds that the JCPDS card number of product is 33-0394, belongs to isometric system.The microscopic appearance of this sample adopts HITACHI S4800 type scanning electronic microscope to observe, and the result is Fig. 2, as can be seen from the figure prepared fusiformis CeO ₂The crystallite mean length is 15 μ m.

Embodiment 2:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.02mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is that the mol ratio of 4:1.5:1 adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 160 ℃ baking oven to react 20h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.

Embodiment 3:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.04mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is that the mol ratio of 6:0.5:1 adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 190 ℃ baking oven to react 10h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.

Embodiment 4:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.05mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is that the mol ratio of 3:2:1 adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 170 ℃ baking oven to react 18h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.

Claims

1. fusiformis CeO ₂The preparation method of crystallite is characterized in that may further comprise the steps:

1) at first, with analytically pure Ce (NO ₃) ₃6H ₂O is dissolved in the solution A of making 0.01～0.05mol/L in the deionized water;

2) secondly, press PEG6000, urea: Ce (NO ₃) ₃6H ₂O is (3～6): (0.5～2): 1 mol ratio adds PEG6000 and urea in the solution A, and 60 ℃ continue to stir 2h and get solution B;

3) last, the solution B after stirring is moved in the reactor, place 160～190 ℃ baking oven to react 10～20h, centrifuge washing after the reaction, 80 ℃ of dryings obtain fusiformis CeO ₂Crystallite.