Abstract
In this study, the hierarchical mesoporous carbon (HMC) was synthesized by the hydrothermal method. The batch adsorption experiments showed that HMC exhibited the ultrafast equilibrium fate (80 % U(VI) capture efficiency within 5 min), high UO
capture capacity (210 mg/g, pH = 4.5) and well recyclability. The investigations of XPS techniques indicated the oxygen-containing functional groups were responsible for high efficient UO
adsorption. The pH-dependent adsorption was simulated by three surface complexation modellings, revealing that UO
adsorption on HMC was excellently fitted by triple layer model using two inner-sphere complexes (i. e. SOUO
and SOUO
(CO
species) compared to constant capacitance model and diffuse layer model. These findings are crucial for expanding actual applications of HMC towards the removal of radionuclides under environmental cleanup.