The efficient enrichment and selection of Au are crucial for gold recovery. The adsorption technology is considered to have potential due to the advantages of operation simplicity and green processability. Nevertheless, the poor Au selectivity at low concentrations in complex solutions limits the further application of the adsorption technology. In this work, a novel Cr-based MOF adsorbent was successfully synthesized using 1,2,4-triazole and 4-aminobenzoic acid as ligands. Benefitting from the surface positive charge and extensive chelation and reduction sites, the novel Cr-based MOF exhibited a total adsorption capacity of up to 357 mg/g and excellent adsorption selectivity toward Au(III) in the complex metal mixed solutions, such as simulated sewage ash waste liquid and actual e-waste leachate. Furthermore, the adsorption kinetics, isotherms, and thermodynamics were discussed in depth for investigating the adsorption mechanisms of the MOF. The PXRD and XPS analyses reveal that the adsorption process involves complexation, redox, and electrostatic interactions. We believe that this study of novel Cr-based MOF adsorbents for efficient Au adsorption is meaningful for further application in the gold recovery technology from e-waste.
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http://dx.doi.org/10.1021/acs.langmuir.2c01137 | DOI Listing |
Adv Mater
November 2024
Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials (SKLPM), SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory (SKAEM-JIL), Department of Chemistry and Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China.
Talanta
December 2024
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China. Electronic address:
In the present research, Fe-based metal-organic frameworks (MIL-101(Fe)-NH) nanoparticles were synthesized by simple solvothermal methods and used to assay Cr(Ⅵ). The MIL-101(Fe)-NH performs dual functions: the 2-aminoterephthalic acid (NH-BDC) ligand endows a strong fluorescence emission, and the Fe metal nodes are able to facilitate the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB) directly, resulting in the generation of oxidized-TMB (ox-TMB). Our research results showed that reducing agents such as ascorbic acid (AA) can collapse the structures of MIL-101(Fe)-NH because of the reduction of Fe by AA, resulting in release of NH-BDC.
View Article and Find Full Text PDFDalton Trans
October 2024
Department of Chemistry, School of Basic Sciences, Central University of Haryana, Mahendergarh 123031, Haryana, India.
We present the use of an amine functionalized two-dimensional clay , aminoclay (AC), in the chemistry of a three-dimensional metal-organic framework (MOF) , MIL-101(Cr), to prepare MIL-101(Cr)/AC composites, which are exploited as catalysts for efficient conversion of CO gas into cyclic carbonates under ambient reaction conditions. Three different MOF nanocomposites, denoted as MIL-101(Cr)/AC-1, MIL-101(Cr)/AC-2, and MIL-101(Cr)/AC-3, were synthesized by an process by adding different amounts of AC to the precursor solutions of the MIL-101(Cr). The composites were characterized by various techniques such as FT-IR, PXRD, FESEM, EDX, TGA, N adsorption, as well as CO and NH-TPD measurements.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2023
College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024, Shanxi Province, China.
Porous materials with d electronic configuration open metal sites have been proved to be effective adsorbents for N capture and N /O separation. However, the reported materials remain challenging to address the trade-off between adsorption capacity and selectivity. Herein, we report a robust MOF, MIL-102Cr, that features two binding sites, can synergistically afford strong interactions for N capture.
View Article and Find Full Text PDFSmall
May 2023
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
A single-layer Cr (HITP) (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) conjugated metal-organic framework (c-MOF) is synthesized under ultrahigh vacuum conditions by substituting Cr for Ni in Ni (HITP) template. As revealed by low-temperature scanning tunneling microscopy and scanning tunneling spectroscopy, while codeposition of Cr atoms and 2,3,6,7,10,11-hexaaminotriphenylene precursors produces irregular branches, crystalline Cr (HITP) frameworks are obtained by depositing Cr atoms to the Ni (HITP) templates. The density functional theory calculations reveal that the binding energy between Cr and HITP ligands is much higher than that for Ni, which hampers the growth of crystalline Cr (HITP) frameworks through direct coordination assembly but makes the substitution reaction energetically favorable.
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