Nitrogen-doped porous carbon from ionic liquid@Al-metal-organic framework: A prominent adsorbent for purification of both aqueous and non-aqueous solutions

Abstract

Nitrogen-doped porous carbons were derived through direct carbonization of ionic liquid (IL)-loaded Al-based metal-organic frameworks (MOFs, or porous coordination polymers) called AlPCP (IL@AlPCP), where IL was added to increase nitrogen contents of derived carbons. Porous carbons derived from IL@AlPCP and pristine AlPCP (called CDIL@AlPCP and CDAlPCP, respectively) were characterized using various techniques and utilized in liquid-phase adsorptions for both aqueous and non-aqueous media to realize their potential application in water and fuel purifications. The adsorptive performance of CDIL@AlPCP was remarkable for the removal of several pharmaceutical and personal care products from water. For example, the adsorption capacity of CDIL@AlPCP was thus far found to be the highest for para-chloro-meta-xylenol (PCMX) as compared with any reported adsorbent (including CDAlPCP and AC). Moreover, CDIL@AlPCP was also very effective for triclosan and acetaminophen adsorptions. Similarly, the efficiency of CDIL@AlPCP for adsorptive desulfurization and denitrogenation of the model fuel was also noticeable. The remarkable adsorption efficiency of CDIL@AlPCP for both aqueous and non-aqueous phases was explained in terms of mainly H-bonding. The direction of H-bonding can also be defined (for example, PCMX contributed as an H-donor, and ample N and O species of carbon materials contributed as an H-acceptor). Moreover, CDIL@AlPCP can be regenerated through simple ethanol washing and can be reused several times. Therefore, CDIL@AlPCP is recommended as a promising adsorbent for purification of both aqueous and non-aqueous solutions.