Tungsten manganese calcium/mesoporous tungsten trioxide compound for preparing photo-anode and preparation method thereof

Abstract

The invention discloses a tungsten manganese calcium / mesoporous tungsten trioxide compound for preparing a photo-anode and a preparation method thereof. The tungsten manganese calcium / mesoporous tungsten trioxide compound is prepared from mesoporous tungsten trioxide and manganese calcium oxide. The mesoporous tungsten trioxide has a shorter electron migration distance, and the island-shaped tungsten manganese calcium oxide is used as an oxygen generation active center sites and has a lower oxygen evolution potential, so that the photo-anode prepared through the compound has higher photocatalysis oxygen generation activity. Compared with a corresponding single-component catalyst, according to a ternary compound semiconductor catalyst, the defects of a single catalyst are overcome through the compounding of manganese calcium and tungsten oxide, and the ternary compound semiconductor catalyst has the advantages of high charge separation efficiency, low oxygen evolution overpotential, good catalytic activity and stability, and the like, and is a promising novel catalytic material for preparing the photo-anode of a photochemical cell.

Description

technical field

[0001] The invention relates to a ternary composite catalyst, in particular to a photoanode material catalyst which can be used to prepare a photocatalytic water photochemical pool and a preparation method thereof. Background technique

[0002] Hydrogen is a clean energy source with high calorific value, environmental friendliness, and convenient transportation. The product of combustion is water, which does not cause any harm to the environment. Water is abundant, readily available, and inexpensive on Earth. Catalytic water splitting to produce hydrogen and oxygen under sunlight irradiation is an ideal way to convert solar energy into chemical energy. The photocatalytic water splitting reaction with industrial practical value is carried out in the photoelectrochemical cell. The water splitting reaction of the photoelectrochemical cell includes two half-reactions, the reduction reaction of photocathode water and the oxidation reaction of photoanode water. ...

Examples

Embodiment 1

[0038] 12g of phosphotungstic acid, 8g of KIT-6 and 200 mL of absolute ethanol were mixed, stirred magnetically for 2 h, and centrifuged. The solid was washed several times with deionized water and dried at 60°C for 10 h. Calcined at 550 °C for 5 h and cooled to room temperature naturally. Disperse the obtained pale yellow solid into 200 mL hydrofluoric acid (2mol / L) and stir for 6 hours, then centrifuge. The solid was washed several times with deionized water and dried in vacuum to obtain mesoporous tungsten trioxide.

[0039] Dissolve 1.2g of calcium acetate monohydrate and 3.98g of manganese acetate tetrahydrate in 30mL of deionized water, and slowly add 30mL of KOH (8.6 mol / L) aqueous solution under magnetic stirring to obtain a brown suspension. Add 100 mL KMnO dropwise to the suspension 4 Aqueous solution (0.06 mol / L), magnetically stirred at room temperature for 8 hours, centrifuged, the solid was washed several times with deionized water, dried in vacuum, and then ca...

Embodiment 2

[0044] Add 1.9g of mesoporous tungsten trioxide and 0.10g of layered manganese-calcium oxide into a 50 mL ball mill jar, and grind on a star ball mill at 500 rpm for 4 hours, and the rest of the steps are the same as in Example 1. A porous tungsten trioxide photocatalytic material with island-like tungsten-manganese-calcium complexes on the surface was prepared, in which the mass fraction of manganese-calcium oxide was 5 wt.%. The photoanode preparation, photocatalytic reactor and photocatalytic reaction conditions are also the same as those in Example 1. After 2 hours of light reaction, when the applied voltage was 0.9V vs. RHE, the yields of hydrogen and oxygen were 1.1 and 0.4 µmol, respectively; when the applied voltage was 1.0 V vs. RHE, the yields of hydrogen and oxygen were 2.0 and 0.9 µmol, respectively; When V vs. RHE, the production of hydrogen and oxygen are 2.5 and 1.1 μmol, respectively; when the applied voltage is 1.2V vs. RHE, the production of hydrogen and oxyg...

Embodiment 3

[0046] After mixing 1.2g of phosphotungstic acid, 2.4g of KIT-6 and 30mL of absolute ethanol, stir magnetically for 2 hours, and centrifuge. The solid is washed several times with deionized water and dried at 60°C for 10 hours. Calcined at 400 °C for 5 h and cooled to room temperature naturally. The obtained pale yellow solid was dispersed into 20 mL of hydrofluoric acid (2mol / L), stirred for 6 hours, and centrifuged. The solid was washed several times with deionized water and dried in vacuum to obtain mesoporous tungsten trioxide. Add 1.86 g of mesoporous tungsten trioxide obtained by this method and 0.14 g of layered manganese-calcium oxide prepared by the method in Example 1 into a 50 mL ball mill jar, and grind for 4 hours on a star ball mill at 500 rpm. One method prepares a porous tungsten trioxide photocatalytic material with an island-shaped tungsten-manganese-calcium compound on the surface, and the mass fraction of manganese-calcium oxide is 7wt.%. The photoanode p...

technical field

[0001] The invention relates to a ternary composite catalyst, in particular to a photoanode material catalyst which can be used to prepare a photocatalytic water photochemical pool and a preparation method thereof. Background technique

[0002] Hydrogen is a clean energy source with high calorific value, environmental friendliness, and convenient transportation. The product of combustion is water, which does not cause any harm to the environment. Water is abundant, readily available, and inexpensive on Earth. Catalytic water splitting to produce hydrogen and oxygen under sunlight irradiation is an ideal way to convert solar energy into chemical energy. The photocatalytic water splitting reaction with industrial practical value is carried out in the photoelectrochemical cell. The water splitting reaction of the photoelectrochemical cell includes two half-reactions, the reduction reaction of photocathode water and the oxidation reaction of photoanode water. ...

Examples

Embodiment 1

[0038] 12g of phosphotungstic acid, 8g of KIT-6 and 200 mL of absolute ethanol were mixed, stirred magnetically for 2 h, and centrifuged. The solid was washed several times with deionized water and dried at 60°C for 10 h. Calcined at 550 °C for 5 h and cooled to room temperature naturally. Disperse the obtained pale yellow solid into 200 mL hydrofluoric acid (2mol / L) and stir for 6 hours, then centrifuge. The solid was washed several times with deionized water and dried in vacuum to obtain mesoporous tungsten trioxide.

[0039] Dissolve 1.2g of calcium acetate monohydrate and 3.98g of manganese acetate tetrahydrate in 30mL of deionized water, and slowly add 30mL of KOH (8.6 mol / L) aqueous solution under magnetic stirring to obtain a brown suspension. Add 100 mL KMnO dropwise to the suspension 4 Aqueous solution (0.06 mol / L), magnetically stirred at room temperature for 8 hours, centrifuged, the solid was washed several times with deionized water, dried in vacuum, and then ca...

Embodiment 2

[0044] Add 1.9g of mesoporous tungsten trioxide and 0.10g of layered manganese-calcium oxide into a 50 mL ball mill jar, and grind on a star ball mill at 500 rpm for 4 hours, and the rest of the steps are the same as in Example 1. A porous tungsten trioxide photocatalytic material with island-like tungsten-manganese-calcium complexes on the surface was prepared, in which the mass fraction of manganese-calcium oxide was 5 wt.%. The photoanode preparation, photocatalytic reactor and photocatalytic reaction conditions are also the same as those in Example 1. After 2 hours of light reaction, when the applied voltage was 0.9V vs. RHE, the yields of hydrogen and oxygen were 1.1 and 0.4 µmol, respectively; when the applied voltage was 1.0 V vs. RHE, the yields of hydrogen and oxygen were 2.0 and 0.9 µmol, respectively; When V vs. RHE, the production of hydrogen and oxygen are 2.5 and 1.1 μmol, respectively; when the applied voltage is 1.2V vs. RHE, the production of hydrogen and oxyg...

Embodiment 3

[0046] After mixing 1.2g of phosphotungstic acid, 2.4g of KIT-6 and 30mL of absolute ethanol, stir magnetically for 2 hours, and centrifuge. The solid is washed several times with deionized water and dried at 60°C for 10 hours. Calcined at 400 °C for 5 h and cooled to room temperature naturally. The obtained pale yellow solid was dispersed into 20 mL of hydrofluoric acid (2mol / L), stirred for 6 hours, and centrifuged. The solid was washed several times with deionized water and dried in vacuum to obtain mesoporous tungsten trioxide. Add 1.86 g of mesoporous tungsten trioxide obtained by this method and 0.14 g of layered manganese-calcium oxide prepared by the method in Example 1 into a 50 mL ball mill jar, and grind for 4 hours on a star ball mill at 500 rpm. One method prepares a porous tungsten trioxide photocatalytic material with an island-shaped tungsten-manganese-calcium compound on the surface, and the mass fraction of manganese-calcium oxide is 7wt.%. The photoanode p...

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