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Heavy metal cations such as Ag+, Pb2+, and Hg2+ can accumulate in living organisms, posing severe risks to biological systems, including humans. Therefore, removing heavy metal cations from wastewater is crucial before discharging them to the environment. However, trace levels and high-capacity removal of the heavy metals remain a critical challenge. This work demonstrates the synthesis and characterization of [Mo2S12]2− intercalated cobalt aluminum-layered double hydroxide, CoAl―Mo2S12―LDH (CoAl―Mo2S12), and its remarkable sorption properties for heavy metals. This material shows high efficiency for removing over 99.9% of Ag+, Cu2+, Hg2+, and Pb2+ from 10 ppm aqueous solutions with a distribution constant, Kd, as high as 107 mL/g. The selectivity order for removing these ions, determined from the mixed ion state experiment, was Pb2+ < Cu2+ ≪ Hg2+ < Ag+. This study also suggests that CoAl―Mo2S12 is not selective for Ni2+, Cd2+, and Zn2+ cations. CoAl―Mo2S12 is an efficient sorbent for Ag+, Cu2+, Hg2+, and Pb2+ ions at pH~12, with the removal performance of both Ag+ and Hg2+ cations retaining > 99.7% across the pH range of ~2 to 12. Our study also shows that the CoAl―Mo2S12 is a highly competent silver cation adsorbent exhibiting removal capacity (qm) as high as ~918 mg/g compared with the reported data. A detailed mechanistic analysis of the post-treated solid samples with Ag+, Hg2+, and Pb2+ reveals the formation of Ag2S, HgS, and PbMoO4, respectively, suggesting the precipitation reaction mechanism.
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This content will become publicly available on January 1, 2026
A Novel Fluorescent Chemosensor Based on Rhodamine Schiff Base: Synthesis, Photophysical, Computational and Bioimaging Application in Live Cells
A novel rhodamine-6G derivative, RdN, was synthesized by condensing rhodamine glyoxal and 3-hydroxy-2-naphthoic hydrazide using a microwave irradiation-assisted reaction. Colorimetric and photophysical studies have demonstrated that the molecule produced can selectively sense Pb2+ and Cu2+ ions in a solution of CH3CN/H2O (9:1, v/v). The spirolactam ring of RdN opens upon complexation with the cations, forming a highly fluorescent complex and a visible color change in the solution. The compound RdN was further studied with the help of computational methods such as the Density Functional Theory (DFT) method and time-dependent density functional theory (TD-DFT) calculations to study the binding interactions and properties of the molecule. DFT calculations and job plot data supported the 2:1 complex formation between RdN and Pb2+/Cu2+. The limit of detection for Pb2+ was determined to be 0.112 µM and 0.130 µM for Cu2+. The probe RdN was applied to the image of Pb2+ and Cu2+ ions in living cells and is safe for biomedical applications. It is used to monitor Pb2+ in environmental water samples.
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- Award ID(s):
- 2100629
- PAR ID:
- 10596067
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Inorganics
- Volume:
- 13
- Issue:
- 1
- ISSN:
- 2304-6740
- Page Range / eLocation ID:
- 5
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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