Adsorption performance and mechanism of g-C3N4/UiO-66 composite for U(VI) from aqueous solution

• Published in: Journal of radioanalytical and nuclear chemistry Vol. 331; no. 1; pp. 469 - 481
• Main Authors: Wu, Jiao, Zheng, Zhouhao, Zhu, Kaihao, Xiang, Chao, Wang, Jingsong, Liu, Jinxiang
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2022; Springer Nature B.V
• Subjects: Adsorption; Aqueous solutions; Carbon nitride; Chemistry; Chemistry and Materials Science; Diagnostic Radiology; Endothermic reactions; Fourier transforms; Functional groups; Hadrons; Heavy Ions; Infrared spectroscopy; Inorganic Chemistry; Mathematical models; Nuclear Chemistry; Nuclear Physics; Physical Chemistry; Surface chemistry; Surface properties; Uranium; X ray photoelectron spectroscopy; Adsorption; UiO-66; Performance; g-C; Uranium (VI); N; Mechanism
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-021-08116-w

The uranium (VI) adsorption performance of g-C 3 N 4 /UiO-66 composite (CNUIO) was evaluated under different solution pH values, adsorbent dosages, coexisting ions, contact times, initial U(VI) concentrations, and temperatures. The surface properties and the interaction mechanism between U(VI) and CNUIO were analyzed via SEM–EDS, BET, FT-IR and XPS. CNUIO exhibited the maximum adsorption rate of 95.01% under the conditions of C U(VI)  = 10 mg/L, pH = 6, M/V = 0.4 g/L, t  = 120 min, and T  = 298 K, which was about 25% and 33.73% higher than that of g-C 3 N 4 and UiO-66, respectively. The adsorption process was found to be a spontaneous endothermic process and conformed to the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model. SEM–EDS and BET analysis revealed that increasing the specific surface area effectively improved the adsorption capacity of CNUIO. FT-IR spectroscopy and XPS indicated that the removal of U(VI) was attributed to the coordination complexation between the nitrogen-containing and the oxygen-containing functional groups of CNUIO and U(VI). Adsorption–desorption experiment demonstrated that CNUIO has a good reusability.