Strengthening of Graphene Aerogels with Tunable Density and High Adsorption Capacity towards Pb2+

Abstract

Graphene aerogels (GAs) with high mechanical strength, tunable density and volume have been prepared only via soaking graphene hydrogels (GHs) in ammonia solution. The density and volume of the obtained GAs are controlled by adjusting the concentration of ammonia solution. Although volume of the GAs decreases with increasing the concentration of ammonia solution, its specific surface area maintains at about 350 m2 g−1, and the inner structure changes to radial after ammonia solution treatment. Thus, GAs are particularly suitable for the adsorption and energy storage applications owing to their high specific surface area and unique porous structure. The adsorption capacity of GAs for Pb2+ from aqueous solution maintains at about 80 mg g−1, which could reach as high as 5000 g m−3 per unit volume and they can be separated easily from water after adsorption.

Facile Fabrication of 3D SiO2@Graphene Aerogel Composites as Anode Material for Lithium Ion Batteries

“…6A, the cylindrical morphology and the ultralight characteristic of SiO 2 @GA composites, which is similar to that of pure GA reported previously [29]. Furthermore, the well-defined and interconnected 3D porous network is also imaged by SEM and TEM.…”

“…GO was prepared from natural graphite flakes with a modified Hummers' method with the reference to the literature [29,30]. Briefly, the graphite flakes were pretreated in the mixture of H 2 SO 4 and HNO 3 (3: 1), washed with deionized (DI) water, and dried at 60 C. 98% H 2 SO 4 (140 ml) was added into a 1000 ml round bottom flask with the pretreated graphite powders (5.0 g) and potassium nitrates (2.5 g) in an ice bath ($2 C).…”

Nitrogen-doped graphene aerogels as anode materials for lithium-ion battery: Assembly and electrochemical properties

“…Graphite powders were pretreated with the mixture of H 2 SO 4 and HNO 3 , washed with deionized water, and dried at 60 • C. Then, they were used to prepare graphite oxide (GO) solution by a modified Hummers method [6]. The synthesis procedure of N-GA was as follows.…”

Mechanical and electro-mechanical properties of three-dimensional nanoporous graphene-poly(vinylidene fluoride) composites

“…GOs were chemically exfoliated from natural graphite flakes via a modified Hummers method [20]. Graphite flakes (5.0 g) (CP, Aladdin Reagent Database Inc., Shanghai, China) and sodium nitrates (2.5 g) (CP, Aladdin Reagent Database Inc., Shanghai, China) were added into concentrated sulfuric acid (115 mL) at room temperature.…”