Central South University of Forestry & Technology

Malachite green (MG), a synthetic dye widely used in industrial applications and aquaculture, poses significant health hazards due to its genotoxic and carcinogenic properties.Addressing these risks requires innovative methods for the efficient MG removal and sensitive detection.In this study, we developed a novel β-cyclodextrin/carbon dots-loaded cellulose nanofibrils/MIL-100(Fe) hydrogel (βCCM) for enhanced adsorption and fluorescence detection of MG.The βCCM demonstrated an exceptional maximum adsorption capacity of 1789 mg/g.Furthermore, βCCM exhibited bright orange fluorescence, which was significantly quenched upon exposure to MG through inner filter effect and static quenching.The fluorescence detection platform exhibited high sensitivity, with a limit of detection (LOD) of 0.09 μg/L and excellent linearity.Its practical applicability was validated through successful MG removal and detection in real water samples, achieving high recoveries and reproducibility.Mechanistic investigations revealed that the enhanced adsorption performance resulted from the incorporation of MIL-100(Fe) and the formation of a three-dimensional (3D) porous structure, which also stabilized the fluorescent signal and amplified detection sensitivity.This study highlights the effectiveness of βCCM for both MG adsorption and detection, presenting a novel strategy for designing advanced β-cyclodextrin-based hydrogels tailored for water treatment.

In this study, a highly stable single-atom Pt-dispersed carbon-deficient graphitic carbon nitride (Pt_SAC/G-CN) photocatalyst with a Pt-N₃ coordination structure was synthesized (supported by X-ray absorbing near-edge structures).The incorporation of Pt atoms altered the electron distribution within the carbon-defective g-C₃N₄ (G-CN), forming a Pt-N₃ coordination structure.This Pt-N₃ coordination structure enhanced the electron transfer efficiency of the photocatalyst, which improved the activation of peroxymonosulfate (PMS) and subsequently facilitated the generation of reactive free radicals.Pt_0.1/G-CN efficiently activated PMS under visible light (λ > 400 nm), resulting in a ciprofloxacin (CIP) degradation of 96.1 % within 150 min.Notably, the turnover frequency (TOF) of Pt_0.1/G-CN is as high as 0.125 min^-1, which is 2-3 orders of magnitude higher than normal Pt-containing catalysts for CIP degradationRadicals quenching experiments and ESR (EPR) indicated that •OH playing crucial roles in the CIP degradation process.Pt_0.1/G-CN exhibited excellent stability and reusability, further emphasizing its practical application potential.Moreover, the role and mechanism of platinum atoms in efficiently activating PMS and degrading quinolone antibiotics under visible light irradiation were also elucidated.These findings provided novel insights into the design of stabilized single-atom metal catalysts for practical use, offering a feasible approach for environmental pollution remediation.

Mechanochem. elemental sulfur-modified petroleum coke (MC-ES-PC) exhibits excellent elemental mercury (Hg⁰) removal from coal-fired flue gas in previous works.However, the detailed removal process and relevant Hg⁰ uptake mechanism have not been sufficiently elucidated or discussed.In this work, kinetic and isothermal adsorption equilibrium were performed to analyze the mercury mechanism of MC-ES-PC sorbents under various flue gas components at different temperaturesThe results showed that chem. adsorption, external mass transfer, and intraparticle diffusion occurred during Hg⁰ immobilization, and they were dominated by chemisorption.Addnl., a gas-solid adsorption equilibrium model for the equilibrium Hg⁰ concentration and adsorption time was established based on the solid-liquid adsorption model, and adsorption equilibrium was divided into several reaction stages by time.The Langmuir and Freundlich models were found to be more suitable for describing Hg⁰ adsorption process of MC-ES-PC, which implies that Hg⁰ adsorption was primarily controlled by its oxidationThis work provides valuable insights into Hg⁰ adsorption mechanism of typical adsorbents.