Nano mesoporous microspherical Bi5O7I photocatalyst and hydrothermal-thermal decomposition preparation method thereof

Abstract

The invention relates to a nano mesoporous microspherical Bi5O7I photocatalyst and a hydrothermal-thermal decomposition preparation method thereof. The Bi5O7I photocatalyst is of a nano mesoporous microspherical shape; the average particle size of microspheres is 1 to 5 microns, and the average aperture of mesoporous on the surface of the microspheres is 7 to 9 nm. The method comprises the following steps: respectively dissolving bismuth salt and iodine salt into quantitative ethylene glycol, performing ultrasonic oscillation treatment, slowly adding iodine salt solution into bismuth salt solution after complete dissolving, performing magnetic stirring to obtain a precursor BiOI, performing hydrothermal reaction on the precursor to prepare BiOI powder, heating the powder body in a tubular furnace under high temperature for decomposition, and preserving the temperature for 2 h to prepare Bi5O7I powder. The Bi5O7I powder prepared by the hydrothermal-thermal decomposition method has the characteristics of uniform shape, high stability and good photocatalysis performance, integrates the advantages of the hydrothermal method and the thermal decomposition method, and is short in reaction time, simple in technological process, lower in raw material cost and suitable for industrial popularization and application.

Description

technical field

[0001] The invention belongs to the technical field of photocatalytic material research, and specifically designs a Bi 5 o 7 I photocatalyst and its hydrothermal-thermal decomposition preparation method. Background technique

[0002] In recent years, bismuth oxyhalides, BiOX (X=Cl, Br, I), belong to P-block compounds, and they usually exhibit a layered crystal structure, and the halogen element layer [X m ] n- with bismuth oxide layer [Bi 2 o 2 ] 2+ The electrostatic interaction between them can promote the separation of photogenerated electron-hole pairs, and the X (X=Cl, Br, I) atomic layers arranged in double layers are formed by X (X=Cl, Br, I) atoms through non-bonding forces Combined, the binding force is small and the structure is loose, so this layered structure is very easy to dissociate along the

[001] direction, and then form a sheet-like nanostructure. Therefore, bismuth oxyhalides have unique advantages in the field of photocatalysis. [...

Examples

Embodiment 1

[0026] (1) The weighed Bi(NO 3 ) 3 ·5H 2 O is placed in 30mL ethylene glycol solution, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.09mol / L. At the same time, place the weighed KI in 20mL of ethylene glycol solution so that the dissolved concentration of KI is 0.15mol / L, and ultrasonically vibrate them respectively at a frequency of 90Hz for 25min. Until it is completely dissolved, it is prepared into bismuth salt solution A and iodine salt solution B respectively.

[0027] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.9:1, magnetically stirred for 60 min to prepare a precursor BiOI solution.

[0028] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 50%, place the reactor in a constant temperature heating box, set the reaction temperature to 180°C, and the holding time to 10h. After the reaction is completed, , naturally cooled to room temperature, t...

Embodiment 2

[0034] (1) Bi(NO 3 ) 3·5H 2 O and KI were placed in 22.1mL and 20mL ethylene glycol solution respectively, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.1mol / L, and the dissolved concentration of KI in the iodized salt solution is 0.13mol / L, and the frequency is 100Hz under the condition of ultrasonic vibration for 30min, until it is completely dissolved, and respectively prepared into bismuth salt solution A and iodized salt solution B .

[0035] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.85:1, magnetically stirred for 50 minutes to prepare a precursor BiOI solution.

[0036] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 65%, place the reactor in a constant temperature heating box, set the reaction temperature to 160°C, and the holding time to 12h. After the reaction is completed, , naturally cooled to room temperature, the yellow precipitate i...

Embodiment 3

[0042] (1) The weighed Bi(NO 3 ) 3 ·5H 2 O is placed in 30mL ethylene glycol solution, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.1mol / L. At the same time, place the weighed KI in 20mL ethylene glycol solution so that the dissolved concentration of KI is 0.17mol / L, and ultrasonically vibrate them respectively at a frequency of 100Hz for 20min. Until it is completely dissolved, it is prepared into bismuth salt solution A and iodine salt solution B respectively.

[0043] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.88:1, magnetically stirred for 40 minutes to prepare a precursor BiOI solution.

[0044] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 70%, place the reactor in a constant temperature heating box, set the reaction temperature to 120°C, and the holding time to 11h. After the reaction is completed, , naturally cooled to room temperature,...

technical field

[0001] The invention belongs to the technical field of photocatalytic material research, and specifically designs a Bi 5 o 7 I photocatalyst and its hydrothermal-thermal decomposition preparation method. Background technique

[0002] In recent years, bismuth oxyhalides, BiOX (X=Cl, Br, I), belong to P-block compounds, and they usually exhibit a layered crystal structure, and the halogen element layer [X m ] n- with bismuth oxide layer [Bi 2 o 2 ] 2+ The electrostatic interaction between them can promote the separation of photogenerated electron-hole pairs, and the X (X=Cl, Br, I) atomic layers arranged in double layers are formed by X (X=Cl, Br, I) atoms through non-bonding forces Combined, the binding force is small and the structure is loose, so this layered structure is very easy to dissociate along the

[001] direction, and then form a sheet-like nanostructure. Therefore, bismuth oxyhalides have unique advantages in the field of photocatalysis. [...

Examples

Embodiment 1

[0026] (1) The weighed Bi(NO 3 ) 3 ·5H 2 O is placed in 30mL ethylene glycol solution, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.09mol / L. At the same time, place the weighed KI in 20mL of ethylene glycol solution so that the dissolved concentration of KI is 0.15mol / L, and ultrasonically vibrate them respectively at a frequency of 90Hz for 25min. Until it is completely dissolved, it is prepared into bismuth salt solution A and iodine salt solution B respectively.

[0027] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.9:1, magnetically stirred for 60 min to prepare a precursor BiOI solution.

[0028] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 50%, place the reactor in a constant temperature heating box, set the reaction temperature to 180°C, and the holding time to 10h. After the reaction is completed, , naturally cooled to room temperature, t...

Embodiment 2

[0034] (1) Bi(NO 3 ) 3·5H 2 O and KI were placed in 22.1mL and 20mL ethylene glycol solution respectively, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.1mol / L, and the dissolved concentration of KI in the iodized salt solution is 0.13mol / L, and the frequency is 100Hz under the condition of ultrasonic vibration for 30min, until it is completely dissolved, and respectively prepared into bismuth salt solution A and iodized salt solution B .

[0035] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.85:1, magnetically stirred for 50 minutes to prepare a precursor BiOI solution.

[0036] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 65%, place the reactor in a constant temperature heating box, set the reaction temperature to 160°C, and the holding time to 12h. After the reaction is completed, , naturally cooled to room temperature, the yellow precipitate i...

Embodiment 3

[0042] (1) The weighed Bi(NO 3 ) 3 ·5H 2 O is placed in 30mL ethylene glycol solution, so that Bi(NO 3 ) 3 ·5H 2 The dissolved concentration of O is 0.1mol / L. At the same time, place the weighed KI in 20mL ethylene glycol solution so that the dissolved concentration of KI is 0.17mol / L, and ultrasonically vibrate them respectively at a frequency of 100Hz for 20min. Until it is completely dissolved, it is prepared into bismuth salt solution A and iodine salt solution B respectively.

[0043] (2) slowly join iodine salt solution B solution in the bismuth salt solution A, make n Bi :n I =0.88:1, magnetically stirred for 40 minutes to prepare a precursor BiOI solution.

[0044] (3) Put the precursor BiOI solution into a polytetrafluoroethylene reactor with a filling ratio of 70%, place the reactor in a constant temperature heating box, set the reaction temperature to 120°C, and the holding time to 11h. After the reaction is completed, , naturally cooled to room temperature,...

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