CN104591264A - Indium oxide nanosphere and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of preparation of inorganic nanometer materials, in particular to an indium oxide nanosphere and a preparation method thereof. The purpose of the present invention is to solve the problems of complex preparation process, high synthesis temperature and long reaction time in the current preparation method of indium oxide nanospheres, and at the same time provide a low-cost indium oxide nanosphere material. The preparation method of the indium oxide nanospheres is as follows: Step 1: Prepare a mixed solution of indium nitrate and urea, add ethanol and/or ethylene glycol to dissolve, and make a uniform colorless and transparent solution after magnetic stirring; Step 2: Mix the colorless The transparent solution is reacted under solvothermal, and the solvothermal product is collected; step 3: the solvothermal product is centrifuged and washed to obtain an indium hydroxide precursor; step 4: the indium hydroxide precursor is roasted at a high temperature to obtain indium oxide nanospheres. The invention has the advantages of simple process, less reactants, lower synthesis temperature and shorter reaction time, so the prepared product has low cost and can be widely used.

Description

A kind of indium oxide nanosphere and preparation method thereof

technical field

The invention belongs to the technical field of preparation of inorganic nanomaterials, and relates to the preparation of indium oxide (In ₂ O ₃ ), in particular to an indium oxide nanosphere and a preparation method thereof.

Background technique

Nano-indium oxide (In ₂ O ₃ ) is an important special n-type semiconductor material with a bandgap width of 3.6~3.75eV, high electrical conductivity and visible light transmittance, and indium oxide is used in chemical and biological sensing , solar cells, photocatalysis, optoelectronics and flat panel displays and other fields have a wide range of applications. The preparation methods of indium oxide mainly include gas phase method, solid phase method and liquid phase method. The gas-phase method has high requirements on equipment parameters and low yield, so it cannot be used in industrial mass production; the particle size of nanoparticles obtained by the solid-phase method is generally not uniform, and its application is also limited. At present, the liquid phase method is widely used, because the temperature required for the liquid phase method is not high, which is conducive to large-scale production.

The liquid phase method mainly includes precipitation method and hydrothermal/solvothermal method in current literature reports. At present, solvothermal method is widely used. Take "Solvothermal synthesis of N-doped CeO ₂ microspheres with visible light-driven photocatalytic activity" as an example , the synthesis of nitrogen-doped CeO ₂ microspheres in its literature uses a solvothermal method, and the CeO ₂ prepared by this method has the ability to degrade rhodamine 6G tetrafluoroborate under visible light ; another example is the literature "Solvothermal synthesis and photocatalytic performance of Mn ⁴⁺ -doped anatase nanoplates with exposed {001} facets", which also uses a solvothermal method to prepare Mn ⁴⁺ doped anatase. At present, solvothermal method is widely used in the preparation of nanomaterials.

Today, nanomaterials and technologies are gradually being used to solve energy and the environment, and have achieved good results. Nano-semiconductor materials are widely used to catalyze the degradation of pollutants in water due to their good photocatalytic activity. The structural morphology and size control of nanomaterials have always attracted extensive attention of researchers, with the aim of making materials with better performance.

Contents of the invention

An object of the present invention is to solve the problems of complex preparation process, high synthesis temperature and long reaction time in the current preparation method of indium oxide nanospheres.

Another object of the present invention is to provide a low-cost indium oxide nanosphere material.

In order to achieve the above object, technical scheme of the present invention is:

A preparation method of indium oxide nanospheres, comprising the following steps in sequence:

Step 1: Prepare a mixed solution of analytically pure indium nitrate and urea. The 1 mmol of indium nitrate is mixed with 1 to 5 mmol of urea, and dissolved in 35 ml of solvent, which is ethanol and/or ethylene glycol. After stirring, a uniform colorless and transparent solution is produced;

Step 2: Transfer the colorless transparent solution to a hydrothermal container, raise the temperature to 120-180° C., heat for 1-12 hours, and collect the solvothermal product after natural cooling;

Step 3: washing and drying the solvothermal product to obtain an indium hydroxide precursor;

Step 4: Calcining the indium hydroxide precursor at a high temperature to obtain indium oxide nanospheres.

In the third step, specifically, the solvothermal product prepared in the second step is centrifuged, washed three times with deionized water and absolute ethanol, and then dried in air at 60-80°C for 6-12 hours.

The high-temperature calcination in step 4 refers to calcination of the indium hydroxide precursor prepared in step 3 in an air atmosphere at 300-600° C. in a muffle furnace for 60-240 min.

Indium oxide nanospheres prepared by the preparation method.

What the present invention adopted is solvothermal method, and its beneficial effect is:

1. The process is simple: because the reactant is indium nitrate, it can be produced under the condition of providing alkaline conditions, that is, the presence of urea, and the presence of solvent ethanol and/or ethylene glycol, without other substances;

2. The synthesis temperature is low, and the temperature of solvothermal synthesis does not exceed 180 degrees; the reaction time is short, and the precursor can be generated within a short time (several hours), and the reaction conditions are not harsh;

3. The cost is low, so the product of the present invention can be widely used in the photodegradation of tetracycline-containing wastewater.

Description of drawings

Fig. 1 is the X-ray diffraction analysis (XRD) pattern of indium oxide prepared by the solvothermal method prepared by the present invention;

Fig. 2 is the spectrum tested under the field emission scanning electron microscope (SEM) of the indium oxide prepared by the present invention;

Fig. 3 is a photocatalytic effect diagram of indium oxide prepared by the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the examples, so that those skilled in the art can better understand the present invention, but the present invention is not limited to the following examples.

Example 1

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 1 mmol of urea to prepare a mixed solution of indium nitrate and urea, dissolve it in 35 mL of ethanol, and configure after magnetic stirring into a uniform colorless transparent solution;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 120°C for 1 hour, and cool naturally to obtain a solvothermal product;

Step 3: Centrifuge the solvothermal product obtained in Step 2, wash it three times with deionized water and absolute ethanol; dry the centrifuged product in air at 60°C for 6 h to obtain the precursor indium hydroxide (In(OH ) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in Step 3 in a muffle furnace at 300 °C in an air atmosphere for 60 minutes to obtain indium oxide (In ₂ O ₃ ) nanospheres.

The experimental steps for the degradation of tetracycline by indium oxide (In ₂ O ₃ ) nanospheres under the xenon lamp light source are as follows:

Evaluation of photocatalytic activity: carried out in GHX-2 photochemical reaction instrument (purchased from Yangzhou University Science and Technology City Technology Co., Ltd.), 100 mL of tetracycline simulated wastewater with a concentration of 20 mg/L was added to the photocatalytic instrument reactor, and then the Indium oxide (In ₂ O ₃ ) nanosphere photocatalyst 0.1 g, reacted for 1 hour in a darkroom with a magnetic stirrer, and started sampling after reaching the reaction adsorption equilibrium, then turned on the aeration device and turned on the xenon lamp light source, and the purpose of aeration was to Keep the catalyst in a suspended or floating state, take samples at intervals of 10 min during xenon light irradiation, take the supernatant after centrifugation and measure the absorbance of the sample at the maximum absorption wavelength of tetracycline λmax=357 nm using a TU-1800 ultraviolet-visible spectrophotometer. And use the formula: D _C =[(A ₀ -A _i )/A ₀ ]×100% to calculate the photodegradation rate, where A ₀ is the absorbance of the tetracycline solution when the adsorption equilibrium is reached, and A _i is the absorbance of the tetracycline solution measured by regular sampling. Absorbance.

The XRD pattern of indium oxide (In ₂ O ₃ ) nanospheres is shown in Figure 1, the product morphology analysis is shown in Figure 2, and the degradation diagram is shown in Figure 3.

The positions and relative intensities of the diffraction peaks in each period in accompanying drawing 1 are all consistent with the JCPDS (Joint Committee on Powder Diffraction Standards) card (06-0416), and there are no other diffraction peaks in the XRD spectrum, indicating that the In _{The 2} O ₃ phase is pure.

In accompanying drawing 2, the field emission scanning electron microscope (SEM) test shows that at room temperature, the diameter of indium oxide (In ₂ O ₃ ) prepared by the solvothermal method is about 400-800 nm.

In Figure 3, the photocatalytic effect diagram shows that the prepared indium oxide nanospheres have a degradation rate of 50.72% for tetracycline under a xenon lamp light source.

Example 2

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 5 mmol of urea, dissolve them in 35 mL of ethylene glycol, and prepare a uniform colorless and transparent solution after magnetic stirring ;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 180°C for 12 hours, and cool naturally to obtain a solvothermal product;

Step 3: Centrifuge the solvothermal product obtained in Step 2, wash it three times with deionized water and absolute ethanol; dry the centrifuged product in air at 80°C for 12 h to obtain the precursor indium hydroxide (In(OH ) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in Step 3 in a muffle furnace at 600 °C in an air atmosphere for 240 minutes to obtain indium oxide (In ₂ O ₃ ) nanospheres.

Example 3

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 1 mmol of urea, dissolve them in 20 mL of ethanol and 15 mL of ethylene glycol, and configure them to be uniform after magnetic stirring Colorless transparent solution;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 120°C for 1 hour, and cool naturally to obtain a solvothermal product;

Step 3: centrifuge the solvothermal product obtained in step B, wash with deionized water and absolute ethanol three times respectively; dry the centrifuged product in air at 80°C for 12 h to obtain the precursor indium hydroxide (In(OH ) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in Step 3 in a muffle furnace at 600 °C in an air atmosphere for 240 minutes to obtain indium oxide (In ₂ O ₃ ) nanospheres.

Example 4

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 5 mmol of urea, dissolve them in 20 mL of ethanol and 15 mL of ethylene glycol, and make them uniform after magnetic stirring Colorless transparent solution;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 180°C for 10 hours, and cool naturally to obtain a solvothermal product;

Step 3: Centrifuge the solvothermal product obtained in Step 2, wash it three times with deionized water and absolute ethanol; dry the centrifuged product in air at 60°C for 6 h to obtain the precursor indium hydroxide (In(OH ) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in Step 3 in a muffle furnace at 300 °C in an air atmosphere for 60 minutes to obtain indium oxide (In ₂ O ₃ ) nanospheres.

Example 5

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 4 mmol of urea, dissolve them in 25 mL of ethanol and 10 mL of ethylene glycol, and configure them to be uniform after magnetic stirring Colorless transparent solution;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 160°C for 3 hours, and cool naturally to obtain a solvothermal product;

Step 3: Centrifuge the solvothermal product obtained in Step 2, wash it three times with deionized water and absolute ethanol respectively; dry the centrifuged product in air at 70°C for 8 h to obtain the precursor indium hydroxide (In(OH ) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in Step 3 in a muffle furnace at 400 °C in an air atmosphere for 120 minutes to obtain indium oxide (In ₂ O ₃ ) nanospheres.

Example 6

A preparation method of indium oxide (In ₂ O ₃ ) nanospheres is carried out according to the following steps:

Step 1: Weigh 1 mmol of indium nitrate (In(NO ₃ ) ₃ 4.5 H ₂ O) and 4 mmol of urea, dissolve them in 15 mL of ethanol and 25 mL of ethylene glycol, and configure them to be uniform after magnetic stirring Colorless transparent solution;

Step 2: Transfer the mixed system obtained in Step 1 to a polytetrafluoroethylene-lined reactor, raise the temperature to 180°C for 5 hours, and cool naturally to obtain a solvothermal product;

Step 3: centrifuge the solvothermal product obtained in step 2, wash with deionized water and absolute ethanol three times respectively; dry the centrifuged product in air at 60°C for 8 hours to obtain the precursor indium hydroxide (In(OH) ₃ );

Step 4: Calcining the indium hydroxide (In(OH) ₃ ) precursor obtained in step 3 in a muffle furnace at 500 °C in an air atmosphere for 240 min to obtain indium oxide (In ₂ O ₃ ) nanospheres.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by the description of the present invention, or directly or indirectly used in other related technical fields, shall be the same as The theory is included in the patent protection scope of the present invention.

Claims (4)

1. a preparation method of indium oxide nanosphere, is characterized in that: comprise the following steps successively: Step 1: Prepare a mixed solution of analytically pure indium nitrate and urea. The 1 mmol of indium nitrate is mixed with 1 to 5 mmol of urea, and dissolved in 35 ml of solvent, which is ethanol and/or ethylene glycol. After stirring, a uniform colorless and transparent solution is produced; Step 2: Transfer the colorless transparent solution to a hydrothermal container, raise the temperature to 120-180° C., heat for 1-12 hours, and collect the solvothermal product after natural cooling; Step 3: washing and drying the solvothermal product to obtain an indium hydroxide precursor; Step 4: Calcining the indium hydroxide precursor at a high temperature to obtain indium oxide nanospheres. 2. the preparation method of indium oxide nanosphere according to claim 1, is characterized in that: In the third step, specifically, the solvothermal product prepared in the second step is centrifuged, washed three times with deionized water and absolute ethanol, and then dried in air at 60-80°C for 6-12 hours. 3. according to the preparation method of the indium oxide nanosphere described in claim 1 or 2, it is characterized in that: The high-temperature calcination in step 4 refers to calcination of the indium hydroxide precursor prepared in step 3 in an air atmosphere at 300-600° C. in a muffle furnace for 60-240 min. 4. according to the indium oxide nanosphere that the described preparation method of claim 1 makes.