Enhanced adsorption of Rhodamine B by magnetic nitrogen-doped porous carbon prepared from bimetallic ZIFs

Heteroatom- doped porous carbons have been proposed as promising adsorbents for wastewater treatment. Here, a nitrogen-enriched magnetic porous carbon was prepared by using bimetallic zeolitic imidazolate frameworks (ZIFs) as the precursors and polyvinyl pyrrolidone (PVP) as the auxiliary carbon/nitrogen source, with direct carbonization at 900 degrees C. The obtained carbon was applied for removing Rhodamine B (RhB) from an aqueous solution. The maximum adsorption capacity for RhB was 137.1 mg/g, which is much higher than those of PVP/ZIF-8 and PVP/ZIF-67 carbons (73.6 mg/g and 87.9 mg/g, respectively), and it could be magnetically separated from the aqueous solution after adsorption.