Bi2WO6/BiOI heterojunction compound photocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the field of photocatalysis and particularly relates to a Bi2WO6 / BiOI heterojunction compound photocatalyst as well as a preparation method and application thereof. The Bi2WO6 / BiOI heterojunction compound photocatalyst is prepared from Bi2WO6 and BiOI, wherein the mol ratio of the BiOI to the Bi2WO6 ranges from (98 to 1) to (1 to 49.5). The preparation method comprises the following steps: preparing the BiOI having a three-dimensional layered micro-ball structure by adopting a hydro-thermal synthesis method; and then treating the BiOI by adopting an ion exchange method under a hydro-thermal condition to obtain the Bi2WO6 / BiOI heterojunction compound photocatalyst. The preparation method provided by the invention has a simple process, and is easy to control and low in cost; a Bi2WO6 / BiOI heterojunction structure having visible-light response is constructed, the separation of photon-generated carriers is accelerated, and the compounding probability of photon-generated ions-hole pairs is reduced; the Bi2WO6 / BiOI heterojunction compound photocatalyst has efficient photocatalytic activity and stability under visible light, and has efficient killing and degradation effects on harmful microorganisms and dye pollutants in a water body; and the Bi2WO6 / BiOI heterojunction compound photocatalyst has a very good practical value and a potential application prospect in the field of water body purification, ocean pollution prevention and the like.

Description

technical field

[0001] The invention belongs to the field of photocatalysis, in particular to a Bi 2 WO 6 / BiOI heterojunction composite photocatalyst and its preparation method and application. Background technique

[0002] Sustainable development is a common concern in the world today. However, problems such as energy shortage and environmental pollution are becoming more and more serious. All kinds of harmful pollutants accumulate, migrate and transform in the water, soil and air environment, seriously destroying the ecological balance and endangering human life and health. In addition, economic development needs to consume a large amount of energy, which is causing a new energy crisis, and a large amount of mining and use of traditional mineral energy itself will cause serious environmental problems.

[0003] Semiconductor photocatalysis technology has great potential in solving energy and environment. Since Fujishima and Honda reported the use of n-type semiconduct...

Examples

Embodiment 1

[0041] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0042] (1) Preparation of BiOI: BiOI with a three-dimensional layered microsphere structure was prepared by hydrothermal synthesis. Weigh 1.0mmolBi(NO 3 ) 3 ·5H 2 O was added to 30.0 mL of absolute ethanol, and ultrasonically dispersed for 30 minutes to obtain dispersion A; at the same time, 1.0 mmol KI and 0.5 g of polyvinylpyrrolidone (PVP) were sequentially added to 30.0 mL of ultrapure water, and magnetically stirred to make it completely Dissolve to obtain the solution B; then add the above solution B dropwise to the above dispersion A under magnetic stirring to obtain a suspension, and use 2.0mol / LNH 3 ·H 2 O solution adjusts the pH of the suspension to 7, and then continues to stir for 60 minutes; after the stirring is completed, transfer the suspension to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and put it in an electric constant temperature blast dry...

Embodiment 2

[0051] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0052] Prepared under hydrothermal conditions by ion exchange method, the difference from Example 1 is that the control of Bi 2 WO 6 The molar ratio with BiOI is 1:9. Weigh the 1.0mmol BiOI obtained above and add it into 30mL ultrapure water, and ultrasonically disperse for 30min to obtain a dispersion; meanwhile, add 0.09mmolNa 2 WO 4 2H 2 O was added to 30mL ultrapure water, and magnetically stirred until it was completely dissolved to obtain a solution; then Na was added dropwise to the above BiOI dispersion. 2 WO 4 The solution was stirred magnetically for 60 minutes to obtain a mixed solution; after that, the mixed solution was transferred to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and placed in an electric constant temperature blast drying oven for heat treatment at 160°C for 24 hours; after the reaction, The reactor was cooled to room temperature, t...

Embodiment 3

[0054] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0055] Prepared under hydrothermal conditions by ion exchange method, the difference from Example 1 is that the control of Bi 2 WO 6 The molar ratio with BiOI is 1:4. Weigh 1.0mmol BiOI obtained above and add it into 30mL ultrapure water, and ultrasonically disperse for 30min to obtain a dispersion; at the same time, add 0.17mmolNa 2 WO 4 2H 2 O was added to 30mL ultrapure water, and magnetically stirred until it was completely dissolved to obtain a solution; then Na was added dropwise to the above BiOI dispersion. 2 WO 4 The solution was stirred magnetically for 60 minutes to obtain a mixed solution; after that, the mixed solution was transferred to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and placed in an electric constant temperature blast drying oven for heat treatment at 160°C for 24 hours; after the reaction, The reactor was cooled to room temperature...

technical field

[0001] The invention belongs to the field of photocatalysis, in particular to a Bi 2 WO 6 / BiOI heterojunction composite photocatalyst and its preparation method and application. Background technique

[0002] Sustainable development is a common concern in the world today. However, problems such as energy shortage and environmental pollution are becoming more and more serious. All kinds of harmful pollutants accumulate, migrate and transform in the water, soil and air environment, seriously destroying the ecological balance and endangering human life and health. In addition, economic development needs to consume a large amount of energy, which is causing a new energy crisis, and a large amount of mining and use of traditional mineral energy itself will cause serious environmental problems.

[0003] Semiconductor photocatalysis technology has great potential in solving energy and environment. Since Fujishima and Honda reported the use of n-type semiconduct...

Examples

Embodiment 1

[0041] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0042] (1) Preparation of BiOI: BiOI with a three-dimensional layered microsphere structure was prepared by hydrothermal synthesis. Weigh 1.0mmolBi(NO 3 ) 3 ·5H 2 O was added to 30.0 mL of absolute ethanol, and ultrasonically dispersed for 30 minutes to obtain dispersion A; at the same time, 1.0 mmol KI and 0.5 g of polyvinylpyrrolidone (PVP) were sequentially added to 30.0 mL of ultrapure water, and magnetically stirred to make it completely Dissolve to obtain the solution B; then add the above solution B dropwise to the above dispersion A under magnetic stirring to obtain a suspension, and use 2.0mol / LNH 3 ·H 2 O solution adjusts the pH of the suspension to 7, and then continues to stir for 60 minutes; after the stirring is completed, transfer the suspension to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and put it in an electric constant temperature blast dry...

Embodiment 2

[0051] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0052] Prepared under hydrothermal conditions by ion exchange method, the difference from Example 1 is that the control of Bi 2 WO 6 The molar ratio with BiOI is 1:9. Weigh the 1.0mmol BiOI obtained above and add it into 30mL ultrapure water, and ultrasonically disperse for 30min to obtain a dispersion; meanwhile, add 0.09mmolNa 2 WO 4 2H 2 O was added to 30mL ultrapure water, and magnetically stirred until it was completely dissolved to obtain a solution; then Na was added dropwise to the above BiOI dispersion. 2 WO 4 The solution was stirred magnetically for 60 minutes to obtain a mixed solution; after that, the mixed solution was transferred to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and placed in an electric constant temperature blast drying oven for heat treatment at 160°C for 24 hours; after the reaction, The reactor was cooled to room temperature, t...

Embodiment 3

[0054] Bi 2 WO 6 / BiOI heterojunction composite photocatalyst preparation method:

[0055] Prepared under hydrothermal conditions by ion exchange method, the difference from Example 1 is that the control of Bi 2 WO 6 The molar ratio with BiOI is 1:4. Weigh 1.0mmol BiOI obtained above and add it into 30mL ultrapure water, and ultrasonically disperse for 30min to obtain a dispersion; at the same time, add 0.17mmolNa 2 WO 4 2H 2 O was added to 30mL ultrapure water, and magnetically stirred until it was completely dissolved to obtain a solution; then Na was added dropwise to the above BiOI dispersion. 2 WO 4 The solution was stirred magnetically for 60 minutes to obtain a mixed solution; after that, the mixed solution was transferred to a high-pressure reactor equipped with a polytetrafluoroethylene liner, and placed in an electric constant temperature blast drying oven for heat treatment at 160°C for 24 hours; after the reaction, The reactor was cooled to room temperature...

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