Heterostructured Photocatalytic Fabric Composed of Ag₃PO₄ Nanoparticle-Decorated NH₂‑MIL-88B (Co/Fe) Crystalline Wires for Rhodamine B Adsorption and Degradation

As an effective and robust wastewater treatment method, a photocatalytic fabric featuring the Z-scheme heterojunction was developed by combining a Co/Fe bimetallic metal–organic framework (NH2-MIL-88B) and Ag3PO4 catalysts. This study reveals that by controlling the Co/Fe molar ratio of NH2-MIL-88B (Co/Fe) (noted as MILx), the nanocrystal structures of the bimetallic MILx and the associated heterojunction with Ag3PO4 (noted as Ag/MILx) were manipulated to perform higher adsorption and accelerated photocatalytic reaction for removing Rhodamine B (RhB) pollutant in water. Photoelectrochemical investigation and scavenging experiments revealed that heterojunction catalysts with bimetallic MILx (Ag/MILx) followed the charge transfer pathways of the Z-scheme, facilitating the generation of •O2– by increasing the conduction band energy position. As a result, at the optimal Co/Fe molar ratio of 0.2 in the heterojunction cocatalyst, RhB adsorption performance was improved by 28% and the RhB degradation was accelerated by 1.5 times compared to the heterojunction formed with Ag3PO4 and single-metal NH2-MIL-88B (Fe). The material developed in this study offers a unique advantage compared to other catalytic materials by strategically utilizing both crystal defects and heterojunction design to enhance the photocatalytic performance. This study is significant in providing crucial empirical evidence that is insightful for designing an effective photocatalytic self-cleaning material composed of complex cocatalytic nanocrystals for enhanced wastewater remediation

Cooperative Design of the Ag₃PO₄/NH₂‑MIL-88B (Fe/Co) Heterojunction Integrated with Conductive Polypyrrole for Advanced Photocatalytic Water Purification

Wastewater treatments using photocatalysts and metal–organic frameworks (MOFs) have gained increasing importance due to their catalytic reactions leading to the decomposition of dyes and organic pollutants without generating secondary pollutants. This work aims at developing an advanced photocatalytic fabric by conceiving a heterojunction of NH2-MIL-88B (Fe/Co) (n-type) and Ag3PO4 (p-type) and increasing the electrical conductivity to facilitate charge transfer at the heterojunction. Of particular interest is the design of a conductive Z-scheme heterophotocatalytic fabric by implementing polypyrrole (PPy) between the heterocatalysts and to investigate the role of the heterojunction and increased conductivity in the generation of reactive species and the photocatalytic mechanism. The electrochemical characterization evinces that the enhanced photocatalytic reaction by the conductive heterojunction is attributed to the efficient electron–hole separation and the increased redox power by the Z-scheme construction. Notably, the implementation of PPy not only accelerated the photocatalytic reactivity by the promoted charge mobility but also improved the structural stability of the catalysts by gluing them on the fabric substrate. The developed photocatalytic system demonstrated significantly enhanced purification performance compared with a single photocatalytic system and showed consistent performance with repeated use cycles. The result of this study implicates that electrical conductivity in a photocatalytic system plays a crucial role in the photocatalytic mechanism, charge mobility, and photocatalytic reactivity

Computational Modeling of Multiscale Air Filter Media Consisting of Nano- and Microfibers

With regard to air filtration, computational work has been performed to predict filter performance outcomes in different particulate scenarios, yet comparative verification of different modeling methods is rarely studied. In this study, computational simulations with different modeling techniques are demonstrated for filter media with various fiber diameters, thicknesses, and basis weights. For a microscale meltblown (Micro) filter web, a resolved model reconstructed by X-ray micro-computed tomography (Xμ-CT) is generated. The representative volume elements and the number of voxels are determined by examining the simulation accuracy and the computational time. For a multiscale dual-layer web composed of nanofibers (Nano) and microscale spunbond fibers (SB), a parametric model and a porous plane model are generated. The accuracy of the models is verified in terms of the morphological parameters and flow resistance in comparison, with actual test results. The parametric model and porous plane model suitably predict the characteristics of multiscale filter media. Simulated filtration is conducted for particles of different sizes (0.05–1 μm) in an effort to understand the relationships among the filter morphology, face velocity (71 and 142 mm/s), and particle size. This study presents relevant modeling methods, specifically a resolved model, a parametric model, and a porous plane model for virtualizing filter media on various scales. It provides an informative discussion of various modeling parameters for accurate predictions of filtering behaviors with potential applicability to the reverse-engineering of filter products

Copper 2‑Methylimidazole Nanostructure-Based Colorimetric Fabric Sensor for Real-Time Monitoring of Ambient Sulfur Oxides

For effective protection from exposure to hazardous gases, a facile strategy of real-time gas monitoring is highly needed. In this study, a novel colorimetric indicator that allows the visual detection of ambient sulfur oxides (SOx) is developed, applying copper 2-methylimidazole [Cu(mIm)] nanocrystals to a cellulose fabric. By optimization of the molar ratio of copper to mIm, the properties of the treated fabric are improved for the Cu(mIm) loading capacity, gas adsorption performance, and colorimetric response. It is revealed that the role of environmental humidity is crucial for effective adsorption and chromatic reaction of Cu(mIm) because the hydrated Cu(mIm) surface facilitates SO2 adsorption, producing reactive species of HSO3– or SO42–. Those reactive SOx species cause the structural transformation of Cu(mIm) and ultimately lead to a chromatic response. The chromatic reaction takes place close to the breakthrough concentration of 5 ppm, demonstrating that the Cu(mIm) fabric can be applied as a practical service-life indicator, timely signaling the replacement time of protective materials. It is anticipated that the proposed strategy offers an effective SOx monitoring solution for application in various fields that call for facile gas detection

Facile Recycling Strategy of Dyed Polyester Waste by Template-Based Synthesis of UiO-66 for Value-Added Transformation into Self-detoxifying Fabrics

Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal–organic framework (MOF) directly on a dyed PET fabric is reported. The advantage of this process lies in its simplicity, where the partial hydrolysis of PET followed by a zirconium chloride treatment results in the successful growth of UiO-66 on a dyed PET fabric with the concurrent removal of the dye without additional steps. The catalytic performance of the UiO-66-grown fabric was evaluated through the degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a nerve agent simulant. The fabric produced by the simple metal treatment (Zr@PEThyd) exhibited excellent DMNP degradation performance with t1/2 = 43.3 min and maintained functional stability after a harsh washing procedure, an outcome attributed to the surface-assisted UiO-66 growth that ensured good bonding stability. The developed process is innovative in that it uses dyed PET waste as a template for the direct growth of UiO-66, simplifying the process without compromising the catalytic functionality. This research provides an informative option for a sustainable textile recycling strategy by transforming dyed PET waste into an advanced self-detoxifying material

Reusable and Biodegradable Separation Membranes Prepared from Common Mushrooms for the Removal of Oily and Particulate Contaminants from Water

Mushroom chitin membranes with controllable pore structures were fabricated through a simple process with naturally abundant Agaricus bisporus mushrooms. A freeze-thaw method was applied to alter the pore structures of the membranes, which consist of chitin fibril clusters within the glucan matrix. With tunable pore size and distribution, mushroom chitin membranes could effectively separate stable oil/water emulsions (dodecane, toluene, isooctane, and chili oil) with various chemical properties and concentrations and particle contaminants (carbon black and microfibers) from water. Chitin fibrils tightly pack with each other to form a dense membrane, leading to no permeation of contaminants or water. An increasing number of applied freeze-thaw cycles confers more tortuous pore structures throughout the mushroom chitin membranes, leading to higher flux while maintaining rejection performance. The 3D simulation constructed by the X-ray computed tomography and GeoDict software also demonstrated capturing a considerable amount of contaminants within the membranes’ pores, which can be easily removed by water rinsing for further successive filtration. Furthermore, mushroom chitin membranes were almost completely biodegraded after approximately a month of being buried in the soil or kept in a lysozyme solution while possessing mechanical durability demonstrated by consistent filtration performance for repeated usage up to 15 cycles under ambient and external pressure. This research is a proof of concept that mushroom-derived chitin develops functional and biodegradable materials for environmental applications with scalability

Reusable and Biodegradable Separation Membranes Prepared from Common Mushrooms for the Removal of Oily and Particulate Contaminants from Water

Mushroom chitin membranes with controllable pore structures were fabricated through a simple process with naturally abundant Agaricus bisporus mushrooms. A freeze-thaw method was applied to alter the pore structures of the membranes, which consist of chitin fibril clusters within the glucan matrix. With tunable pore size and distribution, mushroom chitin membranes could effectively separate stable oil/water emulsions (dodecane, toluene, isooctane, and chili oil) with various chemical properties and concentrations and particle contaminants (carbon black and microfibers) from water. Chitin fibrils tightly pack with each other to form a dense membrane, leading to no permeation of contaminants or water. An increasing number of applied freeze-thaw cycles confers more tortuous pore structures throughout the mushroom chitin membranes, leading to higher flux while maintaining rejection performance. The 3D simulation constructed by the X-ray computed tomography and GeoDict software also demonstrated capturing a considerable amount of contaminants within the membranes’ pores, which can be easily removed by water rinsing for further successive filtration. Furthermore, mushroom chitin membranes were almost completely biodegraded after approximately a month of being buried in the soil or kept in a lysozyme solution while possessing mechanical durability demonstrated by consistent filtration performance for repeated usage up to 15 cycles under ambient and external pressure. This research is a proof of concept that mushroom-derived chitin develops functional and biodegradable materials for environmental applications with scalability

Reusable and Biodegradable Separation Membranes Prepared from Common Mushrooms for the Removal of Oily and Particulate Contaminants from Water

Mushroom chitin membranes with controllable pore structures were fabricated through a simple process with naturally abundant Agaricus bisporus mushrooms. A freeze-thaw method was applied to alter the pore structures of the membranes, which consist of chitin fibril clusters within the glucan matrix. With tunable pore size and distribution, mushroom chitin membranes could effectively separate stable oil/water emulsions (dodecane, toluene, isooctane, and chili oil) with various chemical properties and concentrations and particle contaminants (carbon black and microfibers) from water. Chitin fibrils tightly pack with each other to form a dense membrane, leading to no permeation of contaminants or water. An increasing number of applied freeze-thaw cycles confers more tortuous pore structures throughout the mushroom chitin membranes, leading to higher flux while maintaining rejection performance. The 3D simulation constructed by the X-ray computed tomography and GeoDict software also demonstrated capturing a considerable amount of contaminants within the membranes’ pores, which can be easily removed by water rinsing for further successive filtration. Furthermore, mushroom chitin membranes were almost completely biodegraded after approximately a month of being buried in the soil or kept in a lysozyme solution while possessing mechanical durability demonstrated by consistent filtration performance for repeated usage up to 15 cycles under ambient and external pressure. This research is a proof of concept that mushroom-derived chitin develops functional and biodegradable materials for environmental applications with scalability

MIL-100(Fe)-Hybridized Nanofibers for Adsorption and Visible Light Photocatalytic Degradation of Water Pollutants: Experimental and DFT Approach

As rapid industrial growth spawns severe water contamination and a far-reaching impact on environmental safety, the development of a purification system is in high demand. Herein, a visible light-induced photocatalytic adsorbent membrane was developed by growing a porous metal–organic framework (MOF), MIL-100­(Fe) crystals, onto electrospun polyacrylonitrile (PAN) nanofibers, and its purification capability by adsorption and the photocatalytic effect was investigated. As water-soluble organic foulants, a cationic dye, rhodamine B (RhB), and an anionic dye, methyl orange (MO), were employed, and the adsorption/desorption characteristics were analyzed. Since MIL-100­(Fe) possesses positive charges in aqueous solution, MO was more rapidly adsorbed onto the MIL-100­(Fe) grown PAN membrane (MIL-100­(Fe)@PAN) than RhB. Under visible light, both photocatalytic degradation and adsorption occurred concurrently, facilitating the purification process. The reusability of MIL-100­(Fe)@PAN as an adsorbent was explored by cyclic adsorption–desorption experiments. Density functional theory (DFT) calculations corroborated higher binding energy of charged MO over RhB and demonstrated the possible steric hindrance of RhB to adhere in MOF pores. The emphasis of the study lies in the combined investigation of the experimental approach and DFT calculations for the fundamental understanding of adsorption/desorption phenomena occurring in the purification process. This study provides theoretical support for the interaction between MOF–hybrid complexes and contaminants when MOF-hybridized composites adsorb or photodegrade water-soluble pollutants of different charges and sizes

Sequential Multiscale Simulation of a Filtering Facepiece for Prediction of Filtration Efficiency and Resistance in Varied Particulate Scenarios

This study explores a novel approach of multiscale modeling and simulation to characterize the filtration behavior of a facepiece in varied particulate conditions. Sequential multiscale modeling was performed for filter media, filtering facepiece, and testing setup. The developed virtual models were validated for their morphological characteristics and filtration performance by comparing with the data from the physical experiments. Then, a virtual test was conducted in consideration of a time scale, simulating diverse particulate environments with different levels of particle size distribution, particle concentration, and face velocity. An environment with small particles and high mass concentration resulted in a rapid buildup of resistance, reducing the service life. Large particles were accumulated mostly at the entrance of the filter layer, resulting in a lower penetration and slower buildup of resistance. This study is significant in that the adopted virtual approach enables the prediction of filtration behavior and service life, applying diverse environmental conditions without involving the costs of extra setups for the physical experiments. This study demonstrates a novel and economic research method that can be effectively applied to the research and development of filters