博文
Preparation of Graphite Oxide (to be supplemented）
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Assembly of Graphene Sheets into Hierarchical Structures for High-Performance Energy Storage
Graphite oxide was prepared from natural graphite powder (Sigma, 45 μm) via a modified Hummers method. Typically, graphite powder (0.3 g) was put into an 80 ℃ solution of concentrated H2SO4 (2.4 mL), K2S2O8 (0.5 g), and P2O5 (0.5 g). The mixture was kept at 80 ℃ for 4 h and then cooled to room temperature, diluted with deionized water (DI, 0.5 L), and then filtrated. The powder produced was preoxidized product. The preoxidized graphite was further oxidized in concentrated H2SO4 (12 mL) and KMnO4 (1.5 g). After the addition of KMnO4, the mixture was stirred at 35 ℃ for 2 h. Then, the mixture was diluted with DI water (25 mL) in an ice bath to keep the temperature below 50 ℃. After it was stirred for 2 h, it was further diluted with DI water (70 mL). Then 30% H2O2 (2 mL) was added to the mixture, and a brilliant yellow product was formed. The product was filtrated and washed with HCl aqueous solution (1:10, 1 L) and DI water (1 L). Purified graphite oxide suspensions were then dispersed in water to create a 0.1 wt % dispersion. Exfoliation of graphite oxide was achieved by ultrasonication for 2 h. The obtained brown dispersion was then subjected to 30 min of centrifugation at 3000 rpm to remove any unexfoliated graphite oxide (usually present in a very small amount), using a themo-centrifuge with a rotor radius of 14 cm.
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Graphite oxide was prepared from natural graphite powder (Sigma, 45 μm) via a modified Hummers method. Typically, graphite powder (0.3 g) was put into an 80 ℃ solution of concentrated H2SO4 (2.4 mL), K2S2O8 (0.5 g), and P2O5 (0.5 g). The mixture was kept at 80 ℃ for 4 h and then cooled to room temperature, diluted with deionized water (DI, 0.5 L), and then filtrated. The powder produced was preoxidized product. The preoxidized graphite was further oxidized in concentrated H2SO4 (12 mL) and KMnO4 (1.5 g). After the addition of KMnO4, the mixture was stirred at 35 ℃ for 2 h. Then, the mixture was diluted with DI water (25 mL) in an ice bath to keep the temperature below 50 ℃. After it was stirred for 2 h, it was further diluted with DI water (70 mL). Then 30% H2O2 (2 mL) was added to the mixture, and a brilliant yellow product was formed. The product was filtrated and washed with HCl aqueous solution (1:10, 1 L) and DI water (1 L). Purified graphite oxide suspensions were then dispersed in water to create a 0.1 wt % dispersion. Exfoliation of graphite oxide was achieved by ultrasonication for 2 h. The obtained brown dispersion was then subjected to 30 min of centrifugation at 3000 rpm to remove any unexfoliated graphite oxide (usually present in a very small amount), using a themo-centrifuge with a rotor radius of 14 cm.
https://m.sciencenet.cn/blog-5494-568919.html
上一篇：听党的话，跟党走
下一篇：honeycomb structures films composed of graphene sheets
