Search Results (3,129)

The efficient recovery of highly concentrated cadmium (44.55 g/L) from zinc smelting dust leachate is recognized as a significant metallurgical challenge. In this study, we focused on the selective separation of Cd from coexisting arsenic and zinc using trioctylamine (N235) as the extractant. Accordingly, key operational parameters including initial pH, extractant concentration, phase ratio, and temperature were optimized in a systematic manner. Under the optimized conditions of 30% N235, 15% TBP, and 55% sulfonated kerosene by volume, together with an initial pH of 0.5, an organic to aqueous phase ratio of 1 to 1, and a temperature of 20 °C, a three-stage countercurrent extraction process was found to dramatically enhance the Cd extraction efficiency to 99.80% while successfully rejecting As. Subsequently, stripping with 0.7 mol/L aqueous ammonia achieved an 81.4% stripping efficiency in a single stage, and washing with 1.0 mol/L HCl ensured complete regeneration of the organic solvent. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS) analyses corroborate that the extraction proceeds via an anion exchange mechanism. Specifically, within the chloride rich acidic environment, protonated N235 was shown to preferentially coordinate with the tetrachlorocadmate anion CdCl₄²⁻ to form the highly stable and lipophilic complex (R₃NH)₂CdCl₄. Overall, this work provides a scalable technological framework and a robust theoretical foundation for the extraction of highly concentrated heavy metals from complex secondary metallurgical resources. Full article

Background/Objectives: The widespread presence of antimicrobial-resistant pharmaceutical contaminants in wastewater poses serious ecological and public health risks and remains difficult to address using conventional treatment technologies. Moreover, remediation strategies often involve overlooked environmental burdens, highlighting the need for technologies that are both efficient and environmentally sustainable. This study developed a novel GO/ZIF-60/CoNiAl -LTH (GO/ZIF-60/LTH) ternary nanocomposite adsorbent for removal of ciprofloxacin (CIP) from water matrixes while evaluating its environmental implications using Life cycle assessment (LCA). Methods: The adsorbent was synthesized by integrating graphene oxide (GO) and Ni–Al–Co layered triple hydroxide (LTH) into a ZIF-60 framework. Structural and surface characterization was conducted using XRD, FTIR, SEM–EDX, BET, and UV–Vis analyses. The adsorbent’s CIP aqueous uptake was evaluated through batch experiments supported by kinetic, isotherm, thermodynamic, and response surface methodology (RSM) analyses. Environmental performance was assessed through life cycle-based evaluation. Results: The composite achieved a maximum adsorption capacity of 291 mg g⁻¹ and 91.6% removal efficiency with adsorption following pseudo-first-order kinetics and the Freundlich isotherm. The process was spontaneous and exothermic, with 75% efficiency retained after three regeneration cycles. The LCA revealed an overall global warming impact of 0.953 kg CO₂ eq per functional unit, with the NiAlCo-LTH synthesis stage (1.04 kg CO₂ eq) as the dominant hotspot, followed by final composite formation stage (0.66 kg CO₂ eq). Adsorption and regeneration provided credits (−0.336 and −0.513 kg CO₂ eq), offsetting the upstream impacts. Conclusions: The study demonstrates a new MOF–GO–LTH hybrid adsorbent with high CIP removal efficiency combined with its environmental sustainability assessment, providing a more comprehensive basis for adsorbent evaluation. Although the NiAlCo-LTH component was primarily responsible for the enhanced adsorption performance, yet, it also constituted the major environmental hotspot during its synthesis. These findings highlight the relevance of trade-off between functionality and environmental burden for process optimization, cleaner production, and the sustainable development of advanced adsorbents for pharmaceutical-contaminated water treatment. Full article

Metal–organic frameworks (MOFs) exhibit high specific surface area and porosity, which may facilitate electron transfer during electrochemical reactions. Therefore, it is clear that MOFs are promising materials for the development of electrochemical sensors. In particular, zinc (Zn) based MOFs offer several advantages such as high specific surface area, porosity, environmental friendliness and low cost. Thus, Zn-based MOF materials and their composites have been extensively utilized in the detection of various pollutants, biomolecules and food additives. The Zn-MOF-based materials have been extensively utilized in electrochemical and fluorescence sensing applications. Previously, various Zn-MOF-based sensing systems such as pristine Zn-MOF, carbon-supported Zn-MOF composites, MXene hybrids with Zn-MOF, and bimetallic/trimetallic Zn-based MOFs were explored to enhance sensing performance. Such materials exhibit remarkable analytical performance, such as a low limit of detection (LOD) (nM to pM range), wide linear response range (LR), fast response times, and high selectivity in the presence of interfering species. In electrochemical sensing, Zn-MOF-modified electrodes demonstrated improved charge-transfer kinetics and sensitivity, enabling accurate determination of the biomolecules, drugs and heavy metal ions in real samples. Similarly, Zn-MOF-based fluorescence sensors showed high luminescent properties and displayed sensitive detection of pollutants and biomolecules. Despite such promising sensing performances, some challenges, such as low stability, reproducibility and selectivity in real-time monitoring, etc., remain that need to be overcome. This review article summarizes the previously reported literature on the fabrication of Zn-MOFs, their composites and Zn-MOF-derived materials for the development of electrochemical and fluorescence sensors. We have also discussed the future directions for the rational design of the high-performance Zn-MOF-based sensing systems for environmental and biomedical applications. We believe that the present review article would be useful for the scientific community working on the fabrication of Zn-MOF-based sensors. Full article

Geopolymers, alkali-activated aluminosilicate materials, have gained increasing attention as sustainable adsorbents for wastewater treatment due to their low-temperature synthesis, cost-effectiveness, and ease of shaping into mechanically robust structures. Their intrinsic negatively charged framework promotes the adsorption of cationic species; however, pristine geopolymers typically exhibit moderate performance, with adsorption capacities generally below ~70 mg g⁻¹ for dyes such as methylene blue (MB) and in the range of 20–100 mg g⁻¹ for divalent metal ions. To overcome these limitations, different strategies have been developed to tailor their pore structure and surface chemistry. In particular, foaming approaches enable the production of highly porous materials with tunable pore architecture, improving mass transfer and accessibility of active sites. Moreover, functionalization with carbon-based materials (e.g., activated carbon, graphene derivatives, biochar) or zeolitic phases significantly enhances adsorption performance, with reported capacities exceeding 500 mg g⁻¹ for Pb²⁺ and up to 450 mg g⁻¹ for organic dyes in optimized systems. This review provides a comprehensive overview of recent advances in geopolymer synthesis, pore engineering, and functionalization strategies, highlighting the relationships between composition, structure, and adsorption performance. Particular attention is devoted to the comparison between carbon-based and zeolitic modifications, as well as to the role of material shaping in enabling practical applications. Overall, the combination of tunable porosity, chemical versatility, and structural integrity positions functionalized geopolymers as promising candidates for the development of scalable and multifunctional adsorbents for wastewater remediation. Full article

The electrocatalytic reduction in N₂ and CO₂ into urea under ambient conditions provides a promising strategy for sustainable nitrogen fixation and carbon utilization. However, the low activity and poor selectivity toward urea limit its practical application. Herein, a dual-ligand Cu-based metal–organic framework (Cu-BTC/NH₂BDC) was constructed via ligand engineering strategy. The introduction of 2-NH₂BDC modulated the electronic structure of Cu sites, generating electron-enriched Cu centers that facilitate CO₂ activation, while the hydrogen bonding interaction between the amino and carboxyl groups promotes the activation of N₂. As a result, the optimized Cu-BTC/NH₂BDC catalyst achieved a urea yield of 6.59 mmol g⁻¹ h⁻¹ with a Faradaic efficiency of 22.85% at −0.2 V versus reversible hydrogen electrode (vs. RHE), outperforming single-ligand counterparts. In situ Raman spectroscopy measurement revealed enhanced the formation of *CO, *NN, and C-N intermediates, indicating improved C-N coupling efficiency. This work provides a feasible strategy for regulating active sites in MOF-based catalysts toward efficient urea electrosynthesis. Full article

Photocycloaddition reactions provide an efficient strategy for converting alkenes into structurally complex and high-value molecules that are often difficult to access under conventional thermal conditions. Herein, two readily accessible triarylamine-based imine molecular cages possessing distinct cavity environments were investigated as supramolecular photocatalysts for reactions of pyridinium-masked enol (PME) substrates with unactivated alkenes. Spectroscopic studies are consistent with the formation of electron donor–acceptor (EDA) interactions between the electron-rich cage frameworks and electron-deficient PME substrates. Upon blue-light irradiation (450 nm), these charge-transfer assemblies undergo photoinduced activation, likely involving single-electron transfer, N–O bond cleavage, and subsequent radical generation. The resulting radical intermediates participate in formal [4 + 2] cycloaddition reactions to afford tetralone derivatives under metal-free conditions. Comparative studies revealed that the two cages produce distinct product distributions and selectivities, suggesting that subtle variations in cage architecture and confined supramolecular environments influence the fate of reactive radical intermediates and the balance between productive cyclization and competing side pathways. While the detailed mechanistic origin of these effects remains unresolved, this work demonstrates the potential of covalent organic cages as structurally tunable platforms for modulating EDA-mediated photochemical reactivity and radical selectivity. Full article

Protected cultivation, as a core model of modern agriculture, holds a crucial strategic position in alleviating the shortage of arable land resources and increasing farmers’ income. However, due to the closed environment of protected cultivation, suitable temperature and humidity conditions for pathogen reproduction, serious continuous cropping obstacles, disease transmission easily caused by irrigation, and the lack of natural ultraviolet inhibition and crop rotation conditions, soil-borne pathogens accumulate year by year, resulting in early onset, rapid spread, and great difficulty in control. Traditional pesticide formulations often have limitations such as environmental hazards, low utilization rate, unstable active ingredients, excessive use, and short persistence in the control process. In recent years, pesticide slow-release carriers developed based on nanotechnology to regulate the slow-release behavior of pesticide active ingredients have shown great potential in improving pesticide efficacy and safety. This article reviews several commonly used materials for mineral carriers, metal oxide carriers, organic polymer carriers, and organic–inorganic hybrid carriers. With their high specific surface area, high drug loading rate, environmental friendliness, and stimulus-responsive properties, these materials can significantly improve the effective utilization rate of pesticides, extend the persistence period, and enhance targeting, thus providing strong technical support for solving the problem of soil-borne disease control in protected cultivation and promoting the green and sustainable development of protected cultivation. Full article

This article represents part of a broader research project aimed at developing predictive technologies for identifying prospective mineralized zones based on the analysis of data from an integrated subsurface use platform. The study presents a predictive modeling framework for lithium mineralization within the Kalba–Narym metallogenic zone using machine learning and geostatistical methods. The scientific novelty of the research lies in the integration of geochemical, radiometric, and geophysical data extracted from a cloud-based geospatial platform into a unified mineral prospectivity prediction system. Random Forest (RF), Gaussian Process Regression (GPR), and Empirical Bayesian Kriging (EBK) were applied to predict lithium concentration and analyze spatial patterns. The input data included geochemical indicators, radiometric data, magnetic anomalies, and gravity data. Prior to modeling, all datasets were harmonized into a unified spatial and numerical format. The calculated anisotropy ratio (AR) values revealed the presence of direction-dependent spatial continuity and directional asymmetry within the studied fields. At the same time, the overall similarity of variogram shapes across different directions indicates coherent and structured spatial organization rather than completely random variability. The RF model demonstrated greater effectiveness in identifying localized lithium enrichment anomalies, whereas EBK and GPR better represented regional spatial trends and continuity. The resulting prospectivity maps show spatial correspondence between elevated lithium concentrations and gravity, magnetic, and radiometric anomalies. Five prospective lithium mineralization zones were identified within the study area: East Kalba, Central Kalba, Yeser, Proletarsky, and Kovalevsky. The obtained results confirm the effectiveness of integrating machine learning and geostatistical approaches for rare-metal prospectivity mapping and may support future mineral exploration planning. Full article

Soil potentially toxic elements (PTEs) are crucial indicators of soil quality and ecological risk, especially in areas with complex pedogenesis and intensive anthropogenic activities. However, how soil development and land use jointly shape PTEs’ distribution across multiple scales remains unclear. A multi-scale framework encompassing catchment, sub-catchment, and regional scales was employed to examine the impacts of soil development and land use on PTEs’ (Cr, Ni, Cu, Zn, Pb, Cd, As, and Hg) distribution and their dominant drivers in the lower Yangtze River basin’s alluvial soils. Results showed significant scale-dependent variations in PTEs, with concentrations being highest on the regional scale. During pedogenesis, PTEs exhibited distinct evolutionary patterns across scales: Ni, Cu, Zn, and Cd decreased significantly at both the catchment and sub-catchment scales, whereas Cr, Ni, and As showed increasing trends at the regional scale. Land use also demonstrated scale-dependent effects, with drylands exhibiting PTEs’ enrichment at larger scales but significantly lower concentrations compared to woodlands and paddy-dryland rotation (paddies) at the regional scale. The mechanisms through which the Chemical Index of Alteration (CIA) influences PTE concentrations varied across scales, with metal oxide alteration as a key common pathway. Mantel tests showed that PTE distributions are governed by pH and total phosphorus (TP) at larger scales but by organic carbon (OC) and total nitrogen (TN) regionally. These cross-scale insights reveal how pedogenesis and human activity jointly shape HM patterns, highlighting the potential for scale-appropriate sustainable soil management—for instance, regionally tailored adjustments of pH and organic matter can mitigate metal risks while maintaining soil health. Future studies can build on this multi-scale framework by integrating long-term monitoring with predictive models to assess adaptive strategies under land-use change, thereby advancing sustainability in alluvial agroecosystems. Full article

A simple approach to sample preparation for gas phase breakthrough analysis of adsorbent materials such as metal–organic frameworks is reported. To circumvent issues related to particle size, MOF powders are coated onto glass beads using only the adhesion forces between the glass surface and the particles themselves. These coatings are sufficiently stable for the coated beads to be packed into columns and used for breakthrough measurements of the pure solids. Samples prepared in this manner are compared to analogous samples coated using a binder to attach the MOF to the surface of the beads. In many cases, the approach reported here achieves higher uptake capacities and longer breakthrough times than when a binder is used, presumably because the binder partially clogs the porous structure of the MOF. In addition, an example is discussed that highlights the possibility of a reaction between the sorbent and the binder, highlighting the advantage of a simplified sample preparation method that does not require additional chemical additives. Full article

Given its high energy density and environmentally benign nature, hydrogen has emerged as a sustainable alternative to conventional fossil fuels. Consequently, water electrolysis has attracted considerable attention as a hydrogen production method, with the design of efficient and durable catalytic materials representing a crucial research focus. Herein, we design a two-dimensional metal–organic framework (MOF) for hydrogen evolution electrocatalysis using density functional theory calculation. V₃(C₆O₆)₂, Cr₃(C₆O₆)₂ and Co₃(C₆O₆)₂ emerge as potentially viable, meeting dual criteria of thermodynamic stability and optimal catalytic activity. Notably, Cr₃(C₆O₆)₂ demonstrates unexpectedly high hydrogen evolution reaction (HER) activity comparable to Pt-based catalysts, owing to the moderate H-s/Cr-d-orbital hybridization that fine-tunes H binding. The findings provide substantial theoretical guidance for developing advanced electrocatalysts for sustainable hydrogen evolution. Full article

Metal–organic frameworks (MOFs) offer unique opportunities for drug delivery due to their high porosity and the possibility of hosting large drug molecules within well-defined pore systems. In this work, the zirconium-based MOF NU-1000 was investigated as a carrier for the antineoplastic drug mitoxantrone (MTX). NU-1000 particles were synthesized and characterized by PXRD, SEM, and DLS, confirming their crystallinity, morphology, and size distribution. MTX loading was achieved by aqueous incubation and quantified by UV-Vis spectroscopy and thermogravimetric analysis, yielding a high loading capacity of ~40–43 wt%, with most of the uptake occurring within the first three hours. Structural characterization demonstrated that the MOF preserves its crystallinity and morphology after drug incorporation, while the DLS results suggest that MTX is mainly accommodated within the internal pore system. To improve stability under physiological conditions, the composite was coated with NH₂-PEG-NH₂, resulting in PEG@MTX@NU-1000 particles with enhanced stability in phosphate-buffered saline. Cytotoxicity assays in HeLa cells showed that the PEGylated carrier is largely biocompatible, while PEG@MTX@NU-1000 exhibits a significantly enhanced antiproliferative effect compared to free MTX at short incubation times. These results demonstrate that NU-1000 is a promising platform for MTX delivery, combining high loading capacity, structural stability after PEGylation, and improved short-term therapeutic performance. Full article

Shallow groundwater in the Dongting Lake area is an important resource for domestic, agricultural, and industrial use, and its quality is essential for regional sustainable development and public health. Therefore, effective protection of this resource is urgently needed. In this paper, we integrate Positive Matrix Factorization (PMF) and Self-Organizing Map (SOM) machine-learning algorithms to conduct an in-depth analysis of the distribution, sources, and risks of toxic elements in shallow groundwater along the southern shore of Dongting Lake. The results indicate that Fe and Mn in the groundwater of the study area are at a severe pollution level, while As is at a light pollution level. The model analysis identified four pollution sources: natural sources (Fe, Mn) accounting for 31.33%, agricultural production (Zn) for 18.96%, traffic-mining mixed source (Pb, Cu, Cd) for 32.67%, and mineral dissolution-redox driven (As) for 17.04%. The average concentrations of Fe and Mn exceeded the standard limits. Although the carcinogenic metal Cd did not pose a health risk, the health risk value of As exceeded the maximum acceptable level, which requires serious attention. The PMF model quantified four potential sources of toxic elements, while SOM was used as a complementary nonlinear clustering tool to examine the consistency of the PMF-derived source contribution patterns. The integrated PMF–SOM framework, together with spatial distribution and geochemical evidence, improved the interpretability and robustness of source identification. Full article

High-performance polyethersulfone (PES) ultrafiltration membranes integrating antibacterial activity and antifouling performance were fabricated via the in situ construction of bimetallic polyphenol networks (BMPNs) throughout the membrane architecture. Tannic acid (TA) functioned as a multifunctional molecular bridge, functionalizing silver metal–organic frameworks (Ag-MOFs) to yield hydrophilic T-Ag-MOFs and chelating Fe³⁺ ions from the coagulation bath to form a polyphenol network during phase inversion. T-Ag-MOF incorporation generated asymmetric morphologies featuring highly porous surfaces and sponge-like cross-sections, improving pure water permeability, mechanical integrity, and bovine serum albumin (BSA) rejection. TA-mediated functionalization increased hydrophilicity, imparted a negative surface charge, suppressed nonspecific protein adhesion, and enhanced flux recovery with low irreversible fouling. At an optimal loading of 0.4 wt%, the resultant T-Ag-MOF/Fe³⁺/PES composite membrane achieved a pure water permeability of 593.4 L m⁻² h⁻¹ bar⁻¹—1.77-fold higher than that of the pristine PES control—while sustaining a BSA rejection of 96.5%. Notably, interfacial compatibility between the T-Ag-MOFs and PES matrix was enhanced, facilitating strong, covalent-like filler–matrix adhesion. Moreover, the composite membrane delivered synergistic multifunctionality, including exceptional long-term aqueous stability, precisely tuned Ag⁺ release kinetics, and potent antibacterial activity, as evidenced by negligible uncontrolled ion leaching and a lack of structural degradation under prolonged hydration. Full article

Hierarchical functionalisation of the UiO-66(Zr)-NH₂ metal–organic framework with cysteine, poly(ethylene glycol) (PEG), and the SARS-CoV-2 spike receptor-binding domain (RBD) was developed to enable receptor-specific interaction with the angiotensin-converting enzyme 2 receptor (ACE2) in model cells. Post-synthetic modification using cysteine and heterobifunctional PEG linkers allowed controlled bioconjugation of SpyTag-labelled RBD via SpyTag/SpyCatcher chemistry, while preserving the crystallinity, microporosity, and intrinsic optical properties of the UiO-66(Zr)-NH₂ framework. Comprehensive physicochemical characterisation confirmed successful surface functionalisation, tunable aggregation behaviour, and retention of multimodal optical characteristics. Cellular studies in HEK293T and HeLa cells overexpressing EGFP-tagged ACE2 demonstrated enhanced and selective association and uptake of RBD-functionalised nanoparticles compared with non-targeted analogues. Multimodal fluorescence imaging, fluorescence lifetime imaging microscopy, flow-cytometry, and electron microscopy indicated ACE2-dependent endocytic internalisation, with predominant localisation in endosomal and autophagosomal compartments, while both amine- and cysteine-modified formulations exhibited good biocompatibility. Overall, this study establishes a virus-mimetic, ACE2-targeted UiO-66(Zr)-based nanosystem as a proof-of-concept biointerface platform for receptor-specific cellular delivery and imaging, providing a foundation for future MOF-based nanocarriers exploiting ligand–receptor interactions. Full article