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J. Phys. Chem. C 2010, 114, 1046–1056
Influence of Synthesis Conditions and Heat Treatment on the Structure of Ti3SiC2-Derived Carbons Jun-Seok Bae, Thanh X. Nguyen, and Suresh K. Bhatia* School of Chemical Engineering, The UniVersity of Queensland, St. Lucia, Brisbane QLD 4072, Australia ReceiVed: August 25, 2009; ReVised Manuscript ReceiVed: NoVember 20, 2009
We investigate the characterization and adsorption modeling of Ti3SiC2-derived carbons (Ti3SiC2-DCs) prepared by chlorination at three temperatures (600, 800, and 1000 °C) as well as samples heat-treated at 1100 °C for one and three day periods. The modeling exploits our recent finite wall thickness model-based density functional theory approach (Nguyen, T. X.; Bhatia, S. K. Langmuir 2004, 20, 3532), utilizing experimental adsorption isotherms of Ar at 87 K for the characterization. In general, characterization results show that the carbon wall structure of carbide-derived carbons (CDCs) is precursor-inherited, and Ti3SiC2-DCs have predominantly graphitic walls whose helium density is close to the true density of graphite (2.27 g/cm3), while SiC-derived carbons (SiC-DCs) have predominantly diamond-like walls whose helium density approaches the true density of diamond (3.52 g/cm3). This precursor-inherited character is also seen to give rise to two distinct evolutions of the pore structure of Ti3SiC2-DCs and SiC-DCs under chlorination temperature or post-heat-treatment conditions. In particular, both pore enlargement and opening are observed for Ti3SiC2-DCs, but only pore opening, especially in the region of smallest pores (
