Converting CO2 into an Oxygenated Alkynyl Carbon Material with High Electrochemical Performance through a Mechanochemical Reaction with CaC2

Developing new uses of CO2 and renewable energy technology is crucial for CO2 mitigation, which can be realized simultaneously through the synthesis of advanced functional carbon materials using CO2 as a carbon source. Herein, an oxygenated alkynyl carbon material (OACM) was synthesized via the solvent-free mechanochemical reaction of CaC2 and CO2 under mild conditions, and its electrochemical performance as a supercapacitor electrode was investigated. The gas-solid reaction here is efficient and cost effective owing to the mechanical activation of CaC2. The resultant nanosized OACM features a 3D structure with alkynyl-linked oxygenated carbon chains, hierarchical porosity, numerous defects, high oxygen content, and polycrystalline state. The OACM exhibits high electrochemical performance, including a high specific capacitance (121.8 F g(-1) under 0.15 A g(-1)), superior electrical conductivity (1522 S m(-1)), and excellent cycling stability (above 96.6% in 5000 cycles) due to its unique structure. This work provides a new CO2 use and an innovative synthesis approach for high-performance alkynyl carbon materials.

Automated summary

This study synthesized an oxygenated alkynyl carbon material (OACM) via a solvent-free mechanochemical reaction, which exhibited high electrochemical performance as a supercapacitor electrode. The gas-solid reaction was efficient and cost effective, resulting in a nanosized OACM with a unique structure that contributed to its high specific capacitance, superior electrical conductivity, and excellent cycling stability. This work provides important insights for new uses of CO2 and innovative synthesis methods for high-performance carbon materials.