Carbon aerogel material for reducing and treating Cr (VI) in waste water and preparation method thereof

Abstract

The invention discloses a carbon aerogel material for reducing and treating Cr (VI) in waste water and a preparation method thereof, and belongs to the technical field of synthesis of photocatalytic materials. The key point of the technical scheme comprises that the preparation method comprises the steps: firstly, adopting an improved Hummers' method, preparing graphene oxide with a graphite powder as a raw material; then making the prepared graphene oxide into a graphene oxide aqueous solution with the mass concentration of 2-10 mg / mL, adjusting the pH value of the graphene oxide aqueous solution to 2-13, then placing in a microwave oven, and reducing under a heating condition with the power of 400-800 W; and carrying out dialysis treatment, and freeze-drying to obtain the macroscopic monolithic bulk carbon aerogel material. The invention provides the macroscopic monolithic bulk carbon aerogel material which can efficiently reduce Cr (VI) in chromium-containing waste water under natural sunlight illumination; the carbon aerogel material can be prepared by the simple process and can realize repeated recycling by elastic deformation.

Description

technical field

[0001] The invention belongs to the technical field of synthesis of photocatalytic materials, and in particular relates to a carbon airgel material used for reducing and treating Cr(VI) in wastewater and a preparation method thereof. Background technique

[0002] Chromium is a hard metal with silver-white metallic luster, good ductility, high melting point and corrosion resistance. It is often used as decorative coating and anti-corrosion and wear-resistant materials. Therefore, chromium and its compounds are widely used in industry, and chromium-containing wastewater mainly comes from industries such as metallurgy, electroplating, tanning, chromium salt and chromium compound production. Among the types of heavy metal pollution, chromium pollution ranks second, second only to lead. All chromium compounds are toxic, among which Cr(VI) is the most toxic. Cr(VI) is an ingestion poison / inhalation poison, skin contact may cause sensitivity; it is more likely to ...

Examples

Embodiment 1

[0015] First, graphene oxide was prepared from graphite powder by the improved Hummers’ method (S. Y. Dong, J. Y. Sun, Y. K. Li, C. F. Yu, Y. H. Li, J. H. Sun, ZnSnO 3 hollow nanospheres / reduced graphene oxide nanocomposites as high-performance photocatalysts fordegradation of metronidazole, Appl. Catal. B Environ. 144 (2014) 386-393), and then the prepared graphene oxide was formulated into graphene oxide aqueous solutions with mass concentrations of 2mg / mL, 4mg / mL, 6mg / mL, 8mg / mL, and 10mg / mL to adjust the graphite oxide The pH value of the alkene aqueous solution is 10, and then placed in a microwave oven for reduction under the heating condition of 600W power, and freeze-dried after dialysis treatment to obtain a macroscopic monolithic carbon airgel material. After 8 hours of natural sunlight irradiation, the removal rates of Cr(VI) in chromium-containing wastewater were 80.5%, 92.65%, 99.89%, 99.5% and 99.62%, respectively.

Embodiment 2

[0017] Firstly, graphene oxide was prepared from graphite powder by the improved Hummers' method. In view of the catalyst recovery problem and reduction removal efficiency, this embodiment selects the graphene oxide aqueous solution with a mass concentration of 6 mg / mL as the optimal graphene oxide concentration, and adjusts the pH values ​​of the graphene oxide aqueous solution to 2, 5, 8, 10 and 13, and then placed in a microwave oven for reduction under 600W power heating conditions, after dialysis treatment and then freeze-dried to obtain a macroscopic monolithic carbon airgel material. After 8 hours of natural sunlight irradiation, the removal rates of Cr(VI) in chromium-containing wastewater were 68.95%, 81.89%, 92.66%, 99.89% and 99.97%, respectively.

Embodiment 3

[0019] Firstly, graphene oxide was prepared from graphite powder by the improved Hummers' method. In view of the catalyst recovery problem and reduction removal efficiency, this embodiment selects the graphene oxide aqueous solution with a mass concentration of 6 mg / mL as the optimal graphene oxide concentration, adjusts the pH value of the graphene oxide aqueous solution to 10, and then places them in a microwave oven. Reduction under 400W, 600W and 800W power heating conditions, freeze-drying after dialysis treatment to obtain a macroscopic monolithic carbon airgel material. After being irradiated by natural sunlight for 8 hours, the removal rates of Cr(VI) in chromium-containing wastewater were 78.26%, 99.89% and 99.09%, respectively.

[0020] figure 1 It is the Raman spectrum of the macroscopic monolithic carbon airgel material prepared under optimal conditions. It can be seen from the figure that two typical characteristic peaks of graphene were detected in the sample, r...

technical field

[0001] The invention belongs to the technical field of synthesis of photocatalytic materials, and in particular relates to a carbon airgel material used for reducing and treating Cr(VI) in wastewater and a preparation method thereof. Background technique

[0002] Chromium is a hard metal with silver-white metallic luster, good ductility, high melting point and corrosion resistance. It is often used as decorative coating and anti-corrosion and wear-resistant materials. Therefore, chromium and its compounds are widely used in industry, and chromium-containing wastewater mainly comes from industries such as metallurgy, electroplating, tanning, chromium salt and chromium compound production. Among the types of heavy metal pollution, chromium pollution ranks second, second only to lead. All chromium compounds are toxic, among which Cr(VI) is the most toxic. Cr(VI) is an ingestion poison / inhalation poison, skin contact may cause sensitivity; it is more likely to ...

Examples

Embodiment 1

[0015] First, graphene oxide was prepared from graphite powder by the improved Hummers’ method (S. Y. Dong, J. Y. Sun, Y. K. Li, C. F. Yu, Y. H. Li, J. H. Sun, ZnSnO 3 hollow nanospheres / reduced graphene oxide nanocomposites as high-performance photocatalysts fordegradation of metronidazole, Appl. Catal. B Environ. 144 (2014) 386-393), and then the prepared graphene oxide was formulated into graphene oxide aqueous solutions with mass concentrations of 2mg / mL, 4mg / mL, 6mg / mL, 8mg / mL, and 10mg / mL to adjust the graphite oxide The pH value of the alkene aqueous solution is 10, and then placed in a microwave oven for reduction under the heating condition of 600W power, and freeze-dried after dialysis treatment to obtain a macroscopic monolithic carbon airgel material. After 8 hours of natural sunlight irradiation, the removal rates of Cr(VI) in chromium-containing wastewater were 80.5%, 92.65%, 99.89%, 99.5% and 99.62%, respectively.

Embodiment 2

[0017] Firstly, graphene oxide was prepared from graphite powder by the improved Hummers' method. In view of the catalyst recovery problem and reduction removal efficiency, this embodiment selects the graphene oxide aqueous solution with a mass concentration of 6 mg / mL as the optimal graphene oxide concentration, and adjusts the pH values ​​of the graphene oxide aqueous solution to 2, 5, 8, 10 and 13, and then placed in a microwave oven for reduction under 600W power heating conditions, after dialysis treatment and then freeze-dried to obtain a macroscopic monolithic carbon airgel material. After 8 hours of natural sunlight irradiation, the removal rates of Cr(VI) in chromium-containing wastewater were 68.95%, 81.89%, 92.66%, 99.89% and 99.97%, respectively.

Embodiment 3

[0019] Firstly, graphene oxide was prepared from graphite powder by the improved Hummers' method. In view of the catalyst recovery problem and reduction removal efficiency, this embodiment selects the graphene oxide aqueous solution with a mass concentration of 6 mg / mL as the optimal graphene oxide concentration, adjusts the pH value of the graphene oxide aqueous solution to 10, and then places them in a microwave oven. Reduction under 400W, 600W and 800W power heating conditions, freeze-drying after dialysis treatment to obtain a macroscopic monolithic carbon airgel material. After being irradiated by natural sunlight for 8 hours, the removal rates of Cr(VI) in chromium-containing wastewater were 78.26%, 99.89% and 99.09%, respectively.

[0020] figure 1 It is the Raman spectrum of the macroscopic monolithic carbon airgel material prepared under optimal conditions. It can be seen from the figure that two typical characteristic peaks of graphene were detected in the sample, r...

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