Ordered mesoporous graphitized pyrolytic carbon materials: synthesis, graphitization, and electrochemical properties

Abstract

Ordered mesoporous graphitized pyrolytic carbons have been successfully synthesized via direct chemical vapor deposition from methane with mesoporous silicas as the hard templates. The synthesis procedure is quite simple without use of solvent, catalyst or carrying gas, but efficient for producing mesoporous carbon materials. The whole carbon deposition process is comprehensively studied and illustrated, and the mesostructure regularity, pore architecture, and porosity of the resultant carbon materials can be tuned by simply manipulating the deposition time. The morphological, structural, textural and framework properties of the obtained carbon materials are extensively studied, clearly demonstrating the special features including controllable mesostructures, variable mesopore arrangements, large pore volumes (up to 2.3 cm³ g⁻¹), high surface areas (up to 750 m² g⁻¹) and highly graphitized pore walls with preferred (002) crystal plane orientation. Simple thermal treatment pathways for further promoting the graphitization degree are also proposed. These mesoporous graphitic carbon materials hold promising potential for electrochemical energy storage and conversion applications. They can serve as excellent supports for platinum nanoparticles for oxygen reduction, showing greatly enhanced Pt utilization, activity, methanol tolerance and long-term stability compared to an activated-carbon-supported Pt catalyst. They can be adopted as electrode materials for lithium-ion batteries, showing a high reversible capacity up to ∼340 mAh g⁻¹ and a good cyclic stability. They can also be utilized as electrode materials without the use of any conductive additives for supercapacitors under non-aqueous systems, showing a specific capacitance of ∼40 F g⁻¹ with high Coulombic efficiency and excellent rate performance.