Graphene sheets doped

Fig. 6.15 An example of doped carbon-based nanostructures graphene sheet doped with nitrogen atoms, (a) Possible chemical state of N atoms and (b) electrochemical response of doped and undoped graphene-modified electrodes in the presence of 5 mM H2O2 (Reproduced from Refs. [160] and [161] with the permission of American Chranical Society and Royal Society of Chemistry, respectively)...

Figure 1. CNTs and other nano-sized carbon particles (a) scrolling a graphene sheet (b) closed and opened single-walled CNT (c) double-walled CNT (d) CNT sites doped with boron and nitrogen (e) nanopipettes (f) nanocones and (g) nanorings.

Doping carbon nanotubes with nitrogen atoms at lower concentrations than 6.5 wt% induce crystalline disorder in the graphene sheets, as well as an excess of electron donors on the nitrogen-rich areas may result in a more reactive structure compared to pure carbon nanotubes. For nitrogen-doped carbon nanotubes (N-MWCNT) two types of C-N bonds... 

Besides graphene sheets tested as CO2 capture materials, the introduction of other active sites onto graphene sheets for high-performance CO2 sorbents was also extensively investigated recently [140-142]. For example, PPy functionalized graphene sheets are employed to fabricate N-doped porous carbons via chemical activation [143]. This type of material shows selective adsorption of CO2 (4.3 mmol g ) over N2 (0.27 mmol g ) at 25 °C. Similarly, the highest CO2 uptake (75 mmol g ) at 11 bar and 25 °C over polyaniline-graphene nanocomposites were reported by Mishra and Ramaprabhu [144]. 

Chandra V, Yu SU, Kim SH,Yoon YS, Kim DY, Kwon AH, Meyyappan M, Kim KS (2012) Highly selective CO2 captirre on N-doped carbon produced by chemical activation of polypyrrole functionalized graphene sheets. Chem Commun 48 735-737... 

Lee KR, Lee KU, Lee JW, Ahn BT, Woo SI. Electrochemical oxygen reduction on nitrogen doped graphene sheets in acid media. Electrochem Common 2010 12 1052-5. 

N-doped graphene was also studied as the ORR electrode material. Poly (diallyldimethylammonium chloride) PDDA, as nitrogen source, was introduced into a graphene material. It was observed that PDDA as a p-type dopant could cause the partial electron transfer from the electron-rich graphene substrate to the positively charged N+ centers of PDDA. Thus, carbon atoms in the graphene sheets with the adsorbed PDDA could create somewhat delocalized positive charges on the... 

Gu, Z., and Xu, S. (2010) Large scale synthesis of N-doped multilayered graphene sheets by simple... 

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