In-situ boron and nitrogen doping in flue gas derived carbon materials for enhanced oxygen reduction reaction

Highly active oxygen reduction reaction on Fe-nanoclustered hierarchical porous carbon derived from CO2

This work presents a highly active electrocatalyst of CO₂-derived hierarchical carbon. It retains a high surface area and enables homogeneous insertion of Fe-N-C active sites for the oxygen reduction reaction. The electrocatalyst with a highly interconnected porous structure provides oxygen reduction reaction activity with an E_1/2 difference of 10 mV and a high current density equivalent to Pt/C 20 wt%.

Transformation of carbon dioxide into carbon nanotubes for enhanced ion transport and energy storage

The synthesis of carbon nanotubes (CNTs) from CO₂ is an attractive strategy to reduce CO₂ emission, but involves extreme reaction conditions and has low scalability. This work introduces continuous chemical vapor deposition for the conversion of CO₂ to CNTs using the NaBH₄ reductant and NiCl₂ catalyst. Multi-walled CNT fibers were synthesized from gaseous CO₂ under mild conditions (500-700 °C and 1 atm). Based on in situ analyses, the proposed mechanism behind the formation of CO₂-derived CNTs (CCNTs) is CO₂ activation and subsequent hydroboration for the generation of methane, which can induce the growth of CCNTs on the catalyst. Their intrinsic properties give rise to an enhanced capacitive performance. The boron and oxygen of CCNTs provide a pseudo-capacitance of 302 F g^-1 at a low charging rate of 0.1 A g^-1 in 1 M TEABF₄/acetonitrile. The mesoporous networks between CCNT fibers enhance ion transport at a high current density of 205 A g^-1, leading to an outstanding energy density of 13 W h kg^-1 at a high power density of 115 kW kg^-1. A well-developed graphitized structure of CCNTs contributes to the reduction of the electrochemical resistance and leads to their superior stability at 65 °C during 10 000 cycles.

Enhanced adsorption capacity and selectivity towards strontium ions in aqueous systems by sulfonation of CO2 derived porous carbon

Sulfonated porous carbon (PC-SO₃H) shows enhanced Sr²⁺ adsorption performance in terms of removal capacity, kinetics, and selectivity.