Porous magnetic carbon sheets from biomass as an adsorbent for the fast removal of organic pollutants from aqueous solution

Abstract

A facile and scalable in situ synthetic strategy (simultaneous template–graphitization) was developed to fabricate carbon-stabilized Fe/Fe₃C nanoparticles, which were homogeneously embedded in porous carbon sheets (PMCS) as an excellent adsorbent for wastewater treatment. In the synthesis, the graphitic catalyst precursor (Fe(NO₃)₃) and template agent (Al(NO₃)₃) were introduced simultaneously into the agar hydrogel through the coordination of the metal precursor with the functional groups of agar, thus resulting in simultaneous realization of the template and graphitization of the carbon source under heat treatment. The PMCS with high surface area (1023.2 m² g⁻¹) exhibited high adsorption capacities and fast adsorption rates toward dyes. Using methylene blue (MB), methyl orange (MO) and crystal violet (CV) as model pollutants, the maximum adsorption capabilities for MB, MO, and CV reached 1615.9, 1062.4 and 1728.3 mg g⁻¹, respectively. Moreover, the possibility of magnetic separation also facilitated its application in wastewater treatment on a large scale. This multifunctional material can potentially be used as a super adsorbent to efficiently remove pollutants from wastewater.