Edge-Termination and Core-Modification Effects of Hexagonal Nanosheet Graphene
學年 102
學期 2
出版(發表)日期 2014-02-21
作品名稱 Edge-Termination and Core-Modification Effects of Hexagonal Nanosheet Graphene
著者 Jin-Pei Deng; Wen-Hao Chen; Shou-Po Chiu; Chih-Hsun Lin; Bo-Cheng Wang
單位 化學學系暨研究所
出版者 MDPI
著錄名稱、卷期、頁數 Molecules 19(2), pp.2361-2373
摘要 Optimized geometries and electronic structures of two different hexagonal grapheme nanosheets (HGNSs), with armchair (n-A-HGNS, n = 3–11) and zigzag (n-Z-HGNS, n = 1–8) edges have been calculated by using the GGA/PBE method implemented in the SIESTA package, with the DZP basis set, where n represents the number of peripheral rings. The computed HOMO-LUMO energy gap (Eg = ELUMO − EHOMO) decreases for fully H-terminated A- and Z-HGNSs with increasing n, i.e., with increasing nanosheet size and pπ-orbitals being widely delocalized over the sheet surface. The full terminations, calculated with various functional groups, including the electron-withdrawing (F-, Cl-, and CN-) and -donating (OH-, and SH-) substitutions, were addressed. Significant lowering of EHOMO and ELUMO was obtained for CN-terminated HGNS as compared to those for H-terminated ones due to the mesomeric effect. The calculated Eg value decreases with increasing n for all terminations, whereby for the SH-termination in HGNS, the termination effect becomes less significant with increasing n. Further, the calculation results for stabilities of HGNS oxides support the tendency toward the oxidative reactivity at the edge site of the sheet, which shows most pronounced C-C bond length alternation, by chemical modification. Physical properties of HGNSs with various numbers of the core-defects, which can be obtained by strong oxidation, were also investigated. Their structures can change drastically from planar to saddle-like shapes. These conformations could be used as stationary phases with controlled interaction in the separation methods such as HPLC and the other chemical analysis techniques.
關鍵字 hexagonal grapheme nanosheets;armchair edge;zigzag edge
語言 en_US
ISSN 1420-3049
期刊性質 國外
收錄於 SCI
通訊作者 Bo-Cheng Wang
國別 CHE
出版型式 ,電子版

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/98700 )