Facile fabrication of macroporous carbon materials with Cucurbit[6]uril as precursor/template and its application for uranium removal

Abstract

The macroporous carbon (MC) materials with different mass ratios of cucurbit[6]uril (CB[6]) as precursor/template (CB[6]-MC) have been successfully facile fabricated in strong acid medium. Taking advantage of CB [6] as precursor/template, the unique CB[6]-MC materials with the greatly increased pore size have been firstly used in U (VI) removal from aqueous solution in this study. After removal of CB[6] at 450 °C, the prepared MC materials with large-size cavitis similar as cucurbituril and residual N atoms on the macroporous carbon not only promote the rapid adsorption of the uranyl ions, but also enhance its adsorption capacity. Significantly, the 25% CB[6]-MC material exhibits extremely high maximum adsorption capacity (343.6 mg/g, 4.70mg/m 2 ) for uranyl ions at pH of 5 in aqueous solution, and its adsorption isotherm data fits well by the Langmuir model. Furthermore, it displays stable adsorption performance for uranyl ions after five cycles of recovery, which will make it a promising material in the practical application of radioactive wastewater. • Macroporous carbon (MC) materials using cucurbit[6]uril (CB[6]) as precursor/template have been facile fabricated. • The adsorption capacity of U(VI) ions is almost proportional to the addition amount of CB [6]. • 25% CB [6]-MC exhibits high adsorption capacity (343.6 mg/g, 4.70mg/m 2 ) for U(VI) ions. • MC materials have excellent strength and displays competitive recyclability for U(VI) removal.