A composite of metal-organic framework and MXene for efficient and rapid uranium extraction from seawater
Year: 2023
Type: article
Abstract: As a novel environmentally friendly material, MXene faces challenges due to its inherent chemical instability and ineffective compensation of interlayer electrostatic repulsion. The accumulation and clustering impede its effective surface and the rate of electron and ion transport, thus limiting its practical application. Metal-organic frameworks (MOFs) have rich coordination, tunable porosity and ultra-high specific surface. In this study, composite materials of ZIF-8@MXene and ZIF-67@MXene were synthesized via hydrothermal method. These composites combine zeolitic imidazole frameworks (ZIFs) nanoparticles with MXene nanosheets and were employed for the uranium extraction from seawater. Macroscopic experiments revealed that both ZIF-8@MXene and ZIF-67@MXene exhibited excellent adsorption effects and were able to reach reaction equilibrium quickly (~30 min). The adsorption kinetics data were found to be more consistent with a pseudo-second-order kinetic model. The Freundlich model fitted the thermodynamic data of ZIF-8@MXene well, with a maximum adsorption capacity of 447.4 mg g−1, indicating that UO2(CO3)22− underwent a multiphase adsorption process on the composite surface. The Langmuir model better fitted the thermodynamic data of ZIF-67@Ti3C2Tx with a maximum adsorption capacity of 453.6 mg g−1, indicating that the adsorption process was monolayer adsorption and the active adsorption sites were uniformly dispersed on the adsorbent. According to the analysis of XPS and FTIR before and after reaction, it was found that hydroxyl groups (–OH), nitrogen groups (C=N–) and oxygen-containing functional groups (Zn/Co–O and N–O) acted together during the adsorption process, and chemisorption and surface complexation were the mechanisms for the high adsorption capacity of ZIFs@MXene. This study provided theoretical guidance for the design of high adsorption performance materials and the extraction of uranium from seawater.
Source: Scientia Sinica Chimica
Authors: Shu Zhang, Bing Zhao, Lijie Liu, Xiangxue Wang, Shujun Yu
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4385685359