Electrosynthesis of Two-Dimensional TiC and C Materials from Ti₃SiC₂in Molten Salt

Abstract

The two-dimensional (2-D) multilayer structured TiC and carbide-derived carbon (CDC) have been prepared by electrochemical etching of ternary layered carbide-Ti 3 SiC 2 in molten CaCl 2 at 900 • C with 2.5 V and 3.0 V, respectively. Ti 3 SiC 2 powder was pressed to form a pellet which was then served as the anode, and a graphite rod was used as the cathode. The obtained TiC product possesses a specific surface area of 653 m 2 g −1 and a total pore volume of 0.56 cm 3 g −1 with a narrow pore size distribution (average pore diameter of 2.0 nm). The obtained CDC material shows a layer graphene-like nanosheets structure, and amorphous carbon coexists with graphitic carbon ribbon in the product. The Raman analysis confirms that the I D /I G ratio of the CDC nanosheets is 1.17, indicating the lower degree of graphitization. The layered CDC nanosheets possess a specific surface area of 623 m 2 g −1 and a total pore volume of 2.06 cm 3 g −1 with an average pore diameter of 20-70 nm. It is suggested that the molten salt electrochemical etching process is a novel method for the production of 2-D multilayer material with tuned pores, and have penitential to be used for a variety of applications.

Molten salt electrolytic synthesis of porous carbon from SiC and its application in supercapacitors

“…The pellet was wrapped with porous nickel foil and attached to a Mo wire to assemble the anode. [43][44][45] A schematic of the anode fabrication process is shown in Fig. 2.…”

Tailored Electrosynthesis of Highly Porous Ti3SiC2-Derived Carbon Anodes with Excellent Lithium Storage Properties

“…Molten salt electrochemical etching (MSE) has been proved to be a promising method for the synthesis of CDCs, which shows the facile and environmentally friendly features, and the molten salt has also been proved to be beneficial for the generation of tunable mesoporous architecture. − In our recent work, SiC nanowire and its derived carbon have been successfully prepared through the facile route (SiO 2 /C → SiC → CDC) and the prepared porous carbon nanowires exhibited excellent capacitance and good stability as supercapacitors due to its unique hierarchical pore structures, which were attributed to the molten salt etching process. Subsequently, the strategy has also been extended to etch MAX (Ti 3 SiC 2 and Ti 3 AlC 2 ) for the synthesis of mesopore-rich 2D CDCs, , which shows to be promising as a general strategy for the controllable synthesis of 2D CDC with porous structures. However, the conversion process from MAX material to CDC still needs detailed investigation; in particular, the transformation from MAX to CDCs may involve complex processes such as oxidation, atomic migration, and structural evolution − and thus disclosure of detailed transformation processes is extremely needed.…”

Molten Salt Electrosynthesis of Cr2AlC-Derived Porous Carbon for Supercapacitors

“…Porous carbon materials with layered structure have already been proven to be advantageous for application of supercapacitors. , One of the most well-known cases which has been widely investigated in various electrochemical energy-storage devices is graphene. , Therefore, it is possible to design and synthesize porous CDC from MAX phase materials with a natural layered structure. In recent years, porous carbon has been successfully synthesized by the electrochemical etching process, and much attention has been paid to this method because of its energy efficiency and operability. − In fact, the electrochemical synthetic method has been utilized to synthesize micro/nanostructured metal carbides in molten salt, − which provides a facile electrochemical route to synthesize CDC through combination with the electrochemical in situ etching process . In our previous work, Cr 2 AlC (a typical M 2 AX phase material) and its derived carbon have been successfully synthesized through the facile route (Cr 2 O 3 /Al 2 O 3 /C → Cr 2 AlC → CDC), and the performance of the prepared CDC for Li-ion batteries demonstrated excellent cyclic stability.…”