Copper ions-assisted inorganic dynamic porogen of graphene-like multiscale microporous carbon nanosheets for effective carbon dioxide capture

Abstract

The superior ultramicroporosity and enriched surface CO₂-philic sites are simultaneously required features for high-efficiency carbon-based CO₂ adsorbents. Unfortunately, these characteristics are usually incompatible and difficult to integrate into one porous carbon material. Herein, we report a new copper ions (Cu²⁺)-assisted dynamic porogen to construct hierarchically microporous carbon nanosheets in a large scale with high heterogeneity for solving such issue. Cu²⁺ can be equably dispersed in precursor by coordination interactions of COO-Cu and Cu-N, which can anchor more N/O-containing species in final product. The reduced cuprous ions (Cu⁺) in pyrolysis process functions as a dynamic porogen to tailor uniform ultramicropores. Importantly, copper salt extracted in this synthetic procedure allows cyclic utilization, realizing a green and low-cost process. The obtained carbon sheets possess a graphene-like morphology, a high surface area and a high-proportioned multiscale microporosity, especially a high-density ultramicropores of 0.4-0.7 nm and supermicroproes of 0.8-1.5 nm. The maximized synergistic effect of morphology, high density of multi-sized ultramicroporosity and surface high heterogeneity endow the resultant microporous carbon nanosheets with the remarkable CO₂ capture property, including a high uptake, a moderate adsorption heat, a good selectivity and superior recyclability.

Keywords: CO(2) capture; Dynamic porogen; High heterogeneity; High selectivity; Tailorable ultramicropores.