Method for preparing bismuth tungstate powder with high photocatalytic activity by adopting high-temperature microwave hydrothermal method

A microwave hydrothermal method, catalytic activity technology, applied in chemical instruments and methods, catalyst activation/preparation, physical/chemical process catalysts, etc. consumption effect

Inactive Publication Date: 2012-07-11
SHAANXI UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] TiO 2 Due to its excellent chemical and photocorrosion resistance and low price, it has become the most important photocatalyst in the past few decades. However, due to the influence of TiO 2 The energy band itself is limited, and the utilization rate of sunlight is not high. In recent years, the development of new photocatalysts that can directly use sunlight has become a hot spot in the field of environmental research.

Method used

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  • Method for preparing bismuth tungstate powder with high photocatalytic activity by adopting high-temperature microwave hydrothermal method
  • Method for preparing bismuth tungstate powder with high photocatalytic activity by adopting high-temperature microwave hydrothermal method
  • Method for preparing bismuth tungstate powder with high photocatalytic activity by adopting high-temperature microwave hydrothermal method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Step 1: Weigh Bi(NO 3 ) 3 ·5H 2 O and Na 2 WO 4 2H 2 O was put into a beaker (the raw materials used were analytically pure), and an appropriate amount of deionized water was added to the beaker to make the Bi(NO 3 ) 3 ·5H 2 O concentration is 0.05mol / L, Na 2 WO 4 2H 2 O concentration is 0.025mol / L;

[0032] Step 2: adjust the pH to 1.6, stir magnetically at room temperature for 1 hour to mix the raw materials evenly, and obtain a precursor solution for microwave hydrothermal reaction;

[0033] Step 3: Put the precursor solution obtained in step 2 into a polytetrafluoroethylene-lined reactor, then put the reactor into a microwave hydrothermal reactor MDS-8, set the power to 300W, and set the temperature at 220°C The reaction time is 60mins, and the measured pressure is 3.0Mpa;

[0034] Step 4: After the reaction temperature drops to room temperature, take out the precipitate in the reaction kettle; wash the precipitate with water and absolute ethanol until n...

Embodiment 2

[0036] Step 1: Weigh Bi(NO 3 ) 3 ·5H 2 O and Na 2 WO 4 2H 2 O was put into a beaker (the raw materials used were analytically pure), and an appropriate amount of deionized water was added to the beaker to make the Bi(NO 3 ) 3 ·5H 2 O concentration is 0.04mol / L, Na 2 WO 4 2H 2O concentration is 0.02mol / L;

[0037] Step 2: adjust the pH to 2.6, stir magnetically at room temperature for 1.5 hours to mix the raw materials evenly, and obtain the precursor solution for microwave hydrothermal reaction;

[0038] Step 3: Put the precursor solution obtained in step 2 into a polytetrafluoroethylene-lined reactor, then put the reactor into a microwave hydrothermal reactor MDS-8, set the power to 350W, and set the temperature at 220°C Respond for 30mins, the measured pressure is 3.0Mpa;

[0039] Step 4: After the reaction temperature drops to room temperature, take out the precipitate in the reaction kettle; wash the precipitate with water and absolute ethanol until neutral; dr...

Embodiment 3

[0041] Step 1: Weigh Bi(NO 3 ) 3 ·5H 2 O and Na 2 WO 4 2H 2 O was put into a beaker (the raw materials used were analytically pure), and an appropriate amount of deionized water was added to the beaker to make the Bi(NO 3 ) 3 ·5H 2 O concentration is 0.15mol / L, Na 2 WO 4 2H 2 O concentration is 0.075mol / L;

[0042] Step 2: adjust the pH to 1.5, stir magnetically at room temperature for 2 hours to mix the raw materials evenly, and obtain a precursor solution for microwave hydrothermal reaction;

[0043] Step 3: Put the precursor solution obtained in step 2 into a polytetrafluoroethylene-lined reactor, then put the reactor into a microwave hydrothermal reactor MDS-8, set the power to 450W, and set the temperature at 220°C Respond for 80mins, the measured pressure is 3.0Mpa;

[0044] Step 4: After the reaction temperature drops to room temperature, take out the precipitate in the reaction kettle; wash the precipitate with water and absolute ethanol until neutral; dry ...

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Abstract

The invention provides a method for preparing bismuth tungstate powder with high photocatalytic activity by adopting a high-temperature microwave hydrothermal method. Bismuth nitrate pentahydrate is used as a Bi source, and sodium tungstate dihydrate is used as a W source. The method comprises the following steps of: dissolving the bismuth nitrate pentahydrate and the sodium tungstate dihydrate into deionized water in a molar ratio of Bi to W of 2:1, regulating the pH to be 1.5-3, magnetically stirring for 1 to 2 hours at room temperature to mix the raw materials uniformly to obtain a precursor solution for microwave hydrothermal reaction, transferring the precursor solution to a reaction kettle, reacting for 30 to 90 minutes at the temperature of 220 DEG C by adopting the microwave hydrothermal method, measuring the pressure at 3.0MPa, taking the reaction product out of the reaction kettle after the reaction is stopped, collecting sediment, cleaning and drying, and thus obtaining the bismuth tungstate powder. The bismuth tungstate powder is synthesized by the method at the relatively high temperature of 220 DEG C under the high pressure of 3.0MPa, and the obtained bismuth tungstate powder has high photocatalytic activity in visible light; and the method is short in reaction time which is probably 50 to 60 minutes, low in energy consumption and environment-friendly.

Description

technical field [0001] The invention belongs to the field of functional materials, and relates to a method for preparing bismuth tungstate powder with high photocatalytic activity by using a high-temperature microwave hydrothermal method. Background technique [0002] In 1972, Fujishima and others published TiO 2 After the research paper on hydrogen production from single crystal electrolysis of water, the photocatalytic reaction has attracted the attention of many scholars in the fields of chemistry, physics, materials, and environmental protection. In essence, photocatalysis is the use of light to excite semiconductors, using the electrons and holes they generate to participate in oxidation-reduction reactions. Photocatalytic materials can use solar energy to convert water into hydrogen energy and degrade organic pollutants in the environment. They have the advantages of low cost, high efficiency, and no secondary pollution. They have broad application prospects in solvin...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J23/31B01J37/34
Inventor 谈国强宋丽花
Owner SHAANXI UNIV OF SCI & TECH
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