Recent advances in heteroatom-doped porous carbon for adsorption of gaseous pollutants

Abstract

Due to simple and clean process, and renewable adsorbent, adsorption of gaseous pollutants using porous carbon is a research hotspot in the field of air pollution control. However, the lack of highly active sites and functional groups on porous carbon surface results in low adsorption capacity for gaseous pollutants, hindering the development of this technology. Doping heterogeneous atoms into porous carbon is one of the most effective methods to enhance the surface active sites and functional groups of porous carbon. This paper reviews the latest research progress in doping heterogeneous atoms (e.g., N, O, S, P, halogens, etc.) into porous carbons and adsorption of gaseous pollutants (e.g, SO₂, NO_x, H₂S, Hg⁰, VOCs, etc.) by heteroatom-doped porous carbons. Different heteroatom doping methods, doping effects and mechanisms, and applications are summarized. The adsorption performance and mechanism of heteroatom-doped porous carbons for different gaseous pollutants are also commented on. Results show that doping nitrogen atoms can alter the surface charge distribution and the polarity of porous carbon and produce nitrogen functional groups to improve the van der Waals, dispersive interaction, electrostatic interaction, etc. on porous carbon surface, thereby enhancing pollutants adsorption. Advanced oxidation technologies (AOTs) can induce highly active free radicals to doping oxygen atoms into porous carbon to produce rich oxygen functional groups, which have advantages of high efficiency and clean process, and thus have good development prospects. Multi-elements co-doping can achieve better enhancement effect than single element doping due to synergistic effect between multi-elements and different functional groups. Some suggestions and prospects for development of doping heterogeneous atoms and adsorption of gaseous pollutants using heteroatom-doped porous carbons are also discussed.