PENGARUH LOGAM Li PADA ADSORPSI ATOM-ATOM H OLEH PERMUKAAN GRAFENA PLANAR

Theresia Sita Kusuma, Emdeniz -, Syukri Arief

Abstract

 

ABSTRACT

 

Graphene has future prospect for electronics. By adding some substituents this material can be tuned to behave like a metal or semiconductor. In this investigation, a planar single layer of modified graphene, C24H12-mLim (m = 0, 3, 6, and 12) consisted of seven six-member rings was used to adsorb the oncoming hydrogen (perpendicular to the surface, was defined as Had). A planar twolayer graphene C48H24 (7+7) was also included. To determine the adsorption models and the Had couverage, a semiempiris Calzaferri program, works on pentium 4 windows 98, was used to optimize nHad (n = 1, 2, and 3) that reached the surfaces. The heat of Had adsorption and the band gap of the surfaces were also computed. Results of these computations showed that: (1) the adsorption process was endothermic and Li reduced the heat of Had adsorption on the surfaces. (2) Li reduced the band gap of the surfaces, so C24H12 was a semiconductor but C24Li12 a conductor. (3) The adsorbed nHad always lowered the band gap of the surfaces, in exception of C24Li12 could be lower or higher. (4) Each atom on the surfaces, in exception hydrogen, might adsorb nHad formed tilted (with C) and lying down (with Li) surface complexes, and for C24H6Li6 an asymmetric twofold complex was also observed. (5) However, the Had couverage was low, some Had formed H2 and this was not observed on C24H6Li6. (6) The C48H24 kept an H2 molecule between layers. Thus, a new material C24H6Li6 which had two adsorption models, might increase the Had couverage, but had lower conductivity than that of C24H12. On the other hand, it is necessary to study in more details the hydrogen storage between graphene layers.      

 

 

Key words: graphene, adsorption, substituent

Full Text:

PDF

References

Zhao, X. B., Xiau, B., Fletcher, A. J., and Thomas, K. M., 2005, Hydrogen Adsorption on Functionalized Nanoporous Activated Carbons, J. Phys. Chem. B., 109: 8880-8888.

Park, K. A., Seo, K., and Lee, Y. H., 2005, Adsorption of Atomic Hydrogen on Single-Walled Carbon Nanotubes, J. Phys. Chem. B 2005.,109: 8967-8972.

Bermudez, V. M., 2005, Adsorption on Carbon Nanotubes Studied Using Polarization-Modulated Infrared Reflection-Absorption Spectroscopy, J. Phys. Chem. B., 109: 9970-9979.

Albert, 2006, Pengaruh Li (Pengganti H) pada Adsorpsi Gas H2 oleh Siklasene dengan Empat Cincin, Thesis S2..

Halford, B., 2006, Graphene Eyed as the Next Big Thing in Carbon-Based Electronics, Chemistry and Engeneering, April 17, 34.

Tachikawa, H., and Shimizu, A., 2005, Diffusion Dynamics of the Li+ Ion on a Model Surface of Amorphous Carbons, J. Phys. Chem. B.,109: 13255-13262.

Zhu, Z. H., Lu, G. Q., Wang, F. Y., 2005, Why H Atom Prefers the on Top Site and Alkali Metals Favor the Middle Hollow Site on the Basal Plane of Graphite, J. Phys. Chem. B.,109: 7923-7927.

Kusuma, T. S., 2005, Unpublished Results.

Stojkovic, D., Zhang, P., Lammert, P. E., and Crespi, V. H., 2003, Collective Stabilization of Hydrogen Chemisorption on Graphenic Surfaces, Phys. Rev. B., 68: 195406.

Van Lier, G., Ewels, C. P., Zuliani, F., de Vita, A., and Charlier, J. C., 2005, Theoretical Analysis of Fluorine Addition to Single-Walled Carbon Nanotubes: Functionalization Routes and Addition Patterns, J. Phys. Chem. B., 109: 6153-6158.

Calzaferri, G., and Brandle, M., 1992, QCPE, Program No QCMP 116, Indiana University, Bloomington, Indiana.

Acharya, C. K., and Turner, C. H., 2006, Stabilization of Platinum Clusters by Substitutional Boron Dopants in Carbon Supports, J. Phys. Chem. B., 110: 17706-17710.

Panggabean, Y., 2006, Adsorpsi Atom H pada Permukaan Grafit Planar Satu Lapisan C24H9Li3 dengan Metoda Calzaferri, Skripsi Sarjana Sains.

Kusuma, T. S., Emdeniz, dan Arif, S., 2007, Mempelajari Pengaruh Logam Li pada Adsorpsi Atom-Atom H oleh Permukaan Grafena Planar, Laporan Penelitian Research Grant TPSDP.

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM