Fabrication of hierarchical porous carbide-derived carbons by chlorination of mesoporous titanium carbides

Mesoporous titanium carbides were prepared via carbothermal reduction of organic-inorganic gels using titanium n-butoxide as a Ti source and sucrose as a carbon precursor. The as-made titanium carbides were used as starting materials for producing carbide-derived carbons (CDCs) through thermochemical treatment in a chlorine environment. The influence of the ratio of titanium n-butoxide to sucrose (R) on the porous structure and physical properties of the mesoporous titanium carbide and the resulting CDCs were investigated using X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, and N2 adsorption. It was found that mesoporosity and macroporosity developed in the course of the formation of the titanium carbides can be preserved and transmitted to the carbon material after chlorine treatment, while microporosity was formed by extraction titanium atoms from the carbide. The obtained CDCs have a hierarchical structure of multiscaled pores, including uniform micropores produced from carbides, mesopores with diameter of 3-4 nm original from the residual free carbon and macropores formed by interconnection and overlapping of the carbon particles. By changing the R, the Brunauer-Emmett-Teller specific surface areas and total pore volumes of the CDCs could be adjusted in the range of 1479-1 640 m2/g and 1.06-2.03 cm3/g, respectively. These hierarchical porous carbons would have potential applications for use in catalysis, adsorption, gas separation, and electrochemical energy storage.