Preparation method for visible-light-responsive composite photocatalyst

Abstract

The invention relates to a preparation method for a visible-light-responsive composite photocatalyst. The photocatalyst is a few-layer carbo nitride / zinc oxide compound. The composite photocatalyst is prepared by compounding a certain mass of few-layer carbo nitride (few-layer C3N4) and a certain mass of zinc oxide (ZnO). The preparation method comprises the following concrete steps: placing a prepared flower-like ZnO material in deionized water for ultrasonic treatment until uniform dispersion is realized; then adding a certain mass of few-layer C3N4 and continuing ultrasonic dispersion and stirring for a certain period of time; and then transferring a mixed solution to an oil-bath pan for heating under stirring until evaporation to dryness is realized so as to obtain the few-layer C3N4 / ZnO composite photocatalyst. The results of photocatalysis performance experiments prove that the composite photocatalyst has a wide visible light response range and high photocatalytic activity compared with a non-visible-light-responsive ZnO material with a wide band gap, and has good application prospects and economic benefits in conversion of solar energy, sewage treatment and the like.

Description

technical field

[0001] The invention relates to a preparation method of a visible light responsive photocatalyst, which is a few-layer carbon nitride / zinc oxide composite, and can be used as an environmental functional material in the field of photocatalytic environmental treatment. Background technique

[0002] With the rapid development of economy and society, energy shortage, the contradiction between environmental deterioration and sustainable economic development has become increasingly prominent, photocatalytic technology has attracted widespread attention of scientists in environmental pollution control due to its green sustainability; but many The large band gap and ultraviolet light response of photocatalytic materials have greatly hindered its development and cannot achieve the purpose of large-scale application. Therefore, it is of great practical significance to develop new photocatalysts with high-efficiency visible light response.

[0003] Graphite C 3 N 4 Du...

Examples

Embodiment 1

[0025] Embodiment 1: The present invention is a preparation method of a visible light-responsive photocatalyst, comprising the following steps:

[0026] (1) Put melamine in a muffle furnace, raise the temperature to 550°C at a rate of 2°C / min, and keep it for 4 hours to obtain block graphite type C 3 N 4 .

[0027] (2) The block graphite type C 3 N 4 Thermal exfoliation yields few layers of C 3 N 4 , that is, heating at 550°C for 100min with a heating rate of 2°C / min.

[0028] (3) Zn(NO 3 ) 2 Put it in a beaker, add deionized water for ultrasonic dispersion, and after it is completely dissolved, add a certain amount of ammonia water, the volume ratio of ammonia water to deionized water is 2.5:20.

[0029] (4) Put the mixed solution in (3) into the reaction kettle, react at 160° C. for 12 hours, and wash and dry the flower-shaped ZnO catalyst.

[0030] (5) Weigh 0.05g of ZnO and ultrasonically disperse it in methanol solution for 20min, then add 0.015g of few-layer C ...

Embodiment 2

[0033] Embodiment 2: few layer C of the present invention 3 N 4 / ZnO photocatalyst degrades the application of methylene blue, specifically comprises the following steps: add 50mL MB solution (10mg / L) and 0.01g few-layer C simultaneously in the glass reaction vial 3 N 4 / ZnO catalyst, and then put it in a photoreaction apparatus, pass air in, and magnetically stir in a dark environment for 30 minutes to reach adsorption-desorption equilibrium, and turn on a 300W xenon lamp, and take 4mL solution every 30 minutes and place it in a test tube. Centrifuge and take the supernatant. Use an ultraviolet spectrophotometer (UV-2450) to measure at 663nm and record the data.

[0034] Figure 4 The few-layer C prepared for this example 3 N 4 Kinetic constant diagram of the degradation of methylene blue solution with a concentration of 10 mg / L by / ZnO composite photocatalyst under visible light. As can be seen from the figure, it can be found in the figure that each catalyst exhibits...

technical field

[0001] The invention relates to a preparation method of a visible light responsive photocatalyst, which is a few-layer carbon nitride / zinc oxide composite, and can be used as an environmental functional material in the field of photocatalytic environmental treatment. Background technique

[0002] With the rapid development of economy and society, energy shortage, the contradiction between environmental deterioration and sustainable economic development has become increasingly prominent, photocatalytic technology has attracted widespread attention of scientists in environmental pollution control due to its green sustainability; but many The large band gap and ultraviolet light response of photocatalytic materials have greatly hindered its development and cannot achieve the purpose of large-scale application. Therefore, it is of great practical significance to develop new photocatalysts with high-efficiency visible light response.

[0003] Graphite C 3 N 4 Du...

Examples

Embodiment 1

[0025] Embodiment 1: The present invention is a preparation method of a visible light-responsive photocatalyst, comprising the following steps:

[0026] (1) Put melamine in a muffle furnace, raise the temperature to 550°C at a rate of 2°C / min, and keep it for 4 hours to obtain block graphite type C 3 N 4 .

[0027] (2) The block graphite type C 3 N 4 Thermal exfoliation yields few layers of C 3 N 4 , that is, heating at 550°C for 100min with a heating rate of 2°C / min.

[0028] (3) Zn(NO 3 ) 2 Put it in a beaker, add deionized water for ultrasonic dispersion, and after it is completely dissolved, add a certain amount of ammonia water, the volume ratio of ammonia water to deionized water is 2.5:20.

[0029] (4) Put the mixed solution in (3) into the reaction kettle, react at 160° C. for 12 hours, and wash and dry the flower-shaped ZnO catalyst.

[0030] (5) Weigh 0.05g of ZnO and ultrasonically disperse it in methanol solution for 20min, then add 0.015g of few-layer C ...

Embodiment 2

[0033] Embodiment 2: few layer C of the present invention 3 N 4 / ZnO photocatalyst degrades the application of methylene blue, specifically comprises the following steps: add 50mL MB solution (10mg / L) and 0.01g few-layer C simultaneously in the glass reaction vial 3 N 4 / ZnO catalyst, and then put it in a photoreaction apparatus, pass air in, and magnetically stir in a dark environment for 30 minutes to reach adsorption-desorption equilibrium, and turn on a 300W xenon lamp, and take 4mL solution every 30 minutes and place it in a test tube. Centrifuge and take the supernatant. Use an ultraviolet spectrophotometer (UV-2450) to measure at 663nm and record the data.

[0034] Figure 4 The few-layer C prepared for this example 3 N 4 Kinetic constant diagram of the degradation of methylene blue solution with a concentration of 10 mg / L by / ZnO composite photocatalyst under visible light. As can be seen from the figure, it can be found in the figure that each catalyst exhibits...

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