Enhanced uranium separation by charge enabling γ-MnO2 with oxygen vacancies.
J Hazard Mater
; 459: 132112, 2023 Oct 05.
Article
em En
| MEDLINE
| ID: mdl-37494797
ABSTRACT
Numerous efforts have been devoted to understanding the electron transfer process of uranium (UO22+) on adsorbent materials, whereas the potential oxygen vacancies (OVs) in metal oxides have long been overlooked. Once these interactions are taken into account, the emerging molecular orbital effects undoubtedly affect the adsorption process. Here, we synthesized CC/γ-MnO2 by growing MnO2 on carbon cloth (CC), followed by the creation of oxygen vacancies (OVs) through electrochemical methods to form CC/γ-MnO2-OVs. The CC/γ-MnO2-OVs shows significantly enhanced selectivity and durability for UO22+, with the maximum adsorption capacity increasing from 456.8 to 1648.1 mg/g (by a factor of 3.6). Theoretical calculations suggest that the generation of OVs leads to an increase in charge transfer and a decrease in adsorption energy between UO22+ and CC/γ-MnO2, due to the interaction between Mn 3d orbital in CC/γ-MnO2 and O 2p orbital in UO22+. The OVs in CC/γ-MnO2 provide a spatial structure for anchoring the OU=O moiety of UO22+, while the surface van der Waals forces and the formation of chemical bonds between Mn-U contribute to charge interactions. This synergistic effect allows CC/γ-MnO2-OVs to exhibit favorable selectivity, a large adsorption capacity, and rapid adsorption kinetics towards uranyl ions. This work achieves enhanced UO22+ separation by introducing OVs in CC/γ-MnO2 through a facile electrochemical strategy, highlighting the great potential for nuclear waste processing.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Hazard Mater
Ano de publicação:
2023
Tipo de documento:
Article