Titanium carbide derived nanoporous carbon for energy-related applications

Abstract

High surface area nanoporous carbon has been prepared by thermo-chemical etching of titanium carbide TiC in chlorine in the temperature range 200-1200 °C. Structural analysis showed that this carbide-derived carbon (CDC) was highly disordered at all synthesis temperatures. Higher temperature resulted in increasing ordering and formation of bent graphene sheets or thin graphitic ribbons. Soft X-ray absorption near-edge structure spectroscopy demonstrated that CDC consisted mostly of sp 2 bonded carbon. Small-angle X-ray scattering and argon sorption measurements showed that the uniform carbon-carbon distance in cubic TiC resulted in the formation of small pores with a narrow size distribution at low synthesis temperatures; synthesis temperatures above 800 °C resulted in larger pores. CDC produced at 600-800 °C show great potential for energy-related applications. Hydrogen sorption experiments at −195.8 °C and atmospheric pressure showed a maximum gravimetric capacity of ∼ 330 cm 3 /g (3.0 wt.%). Methane sorption at 25 °C demonstrated a maximum capacity above 46 cm 3 /g (45 vol/vol or 3.1 wt.%) at atmospheric pressure. When tested as electrodes for supercapacitors with an organic electrolyte, the hydrogen-treated CDC showed specific capacitance up to 130 F/g with no degradation after 10 000 cycles.

Carbide-Derived Carbons: Effect of Pore Size on Hydrogen Uptake and Heat of Adsorption

“…Material synthesis: We synthesized CDC from commercially available powders of B 4 C, [17] ZrC, [18] TiC, [20] and SiC [19] at various temperatures in the 400-1200°C range. TiC, ZrC and B 4 C with the average particle size of ∼ 2-4 µm were obtained from Alfa Aesar, while β-SiC powder with the average particle size of ∼ 2 µm was obtained from Superior Graphite.…”

“…A gradual evolution of CDC structure as the chlorination temperature increases was revealed by Raman spectroscopy, X-Ray diffraction (XRD) [17][18][19][20] , and TEM (Fig. 4).…”

High rate performance activated carbons prepared from ginkgo shells for electrochemical supercapacitors

“…Among the researches in EDLCs, it is an important field to develop electrode materials with large specific capacitance and high electrochemical stability [4]. Activated carbons (ACs) satisfy the basic requirements for the electrode materials of EDLCs due to its low cost, high surface area and large porosity [5][6][7][8][9].…”

High selectivity of TiC-CDC for CO2/N2 separation

“…The pore size in these materials is highly influenced by the carbide precursor and reactive extraction temperature. Higher temperatures during synthesis may allow restructuring of the carbon to a higher degree of graphitization and larger pores are formed [6,15,16]. At lower synthesis temperatures carbon molecular sieves can result, which could be of interest for the application of gas separation, e.g.…”

“…The pore structure can be further analyzed by small-angle scattering techniques like X-ray scattering (SAXS) or neutron scattering (SANS), which allows also probing closed pores. For titanium carbide-derived carbon (TiC-CDC), which is subject of this study, sorption isotherm analysis [16][17][18][19][20][21][22] and scattering [16,[23][24][25] results are discussed in literature, showing that TiC-CDC synthesized below 900 °C shows pore sizes in the range of carbon molecular sieves. Equilibrium CO 2 adsorption isotherms demonstrated that with TiC-CDC high CO 2 uptakes can be realized [26].…”