Cellulose–metal organic frameworks (CelloMOFs) hybrid materials and their multifaceted Applications: A review

Modification of cellulose substrate by in situ synthesis of metal-organic framework-5 for thin film microextraction of some non-steroidal anti-inflammatory drugs and their measurement by high-performance liquid chromatography-ultraviolet detector

This work, reports the successful preparation a thin film by a simple and inexpensive process for quantification of a model analytes in the urine sample using HPLC-UV. To this end, cellulose paper was employed as a substrate for the in-situ synthesis of MOF-5, to increase the resistance of the prepared film. The prepared film can be reused 26 times with no reduction in its performance. The thin film prepared by MOF-5 modified cellulose substrate was utilized in thin film microextraction (TFME) method for the extraction and preconcentration of naproxen, aspirin, tolmetin, and celecoxib. Under optimal conditions, the linear dynamic range of the target analytes was 2-500 µg L-1 with correlation coefficients (R2) ranging from 0.9961 to 0.9990. Also, the limits of detection (LODs), the limits of quantification (LOQs) and relative standard deviation (RSD%) of the proposed method for selected analytes ranged between 0.57 and 0.77 µg L-1, 1.7 to 2.3 and 3.5 % to 6.2 %, respectively. Moreover, relative recoveries varied from of 94 % to 108 %, indicating the absence of matrices effect in the proposed method. Eventually, the TFME was successfully used for the extraction of selected analytes from urine samples.

Optimization of cobalt-based MOFs for super-capacitor electrode materials of new energy vehicle

Super-capacitors (SCs), as new energy conversion storage elements, have attracted much attention, but there is still a research gap in the design of electrode materials. In this study, the optimization scheme of Metal-Organic Frameworks (MOFs) and cobalt-based MOF composites as electrode materials for SCs in new energy vehicles is explored, and a series of experiments are conducted to evaluate their performance. Scanning Electron Microscope (SEM) images reveal that the cobalt-based MOF composites have a surface morphology of particles with uniform distribution. The electrochemical performance test results show that the specific capacitance of the cobalt-based MOF composites is much higher than the sum of the two individual electrode materials and presents a remarkable increase with the scanning rate. Additionally, in the constant current charge-discharge test, cobalt-based MOF composites exhibit the longest charge-discharge time and good symmetry. Electrolyte particle contact tests for samples at different preparation temperatures display that high-temperature samples have better structural stability and electrolyte ion contact. In Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests, the 250 °C sample demonstrates the best electrochemical properties and the highest specific capacitance (269 F/g). Moreover, as the current density increases, the specific capacitance of the 600 °C sample decreases at a lower rate, showing stronger stability. However, the use of cobalt-based MOF materials may pose environmental and safety risks, such as the environmental impact of cobalt resource mining, instability under high-temperature conditions, and the possible production of hazardous substances. Therefore, these factors need to be fully considered when designing and using SCs to ensure the environmental friendliness and safety of cobalt-based MOFs. These results provide an important reference for selecting and optimizing electrode materials for SCs in new energy vehicles. Furthermore, this study offers research suggestions for improving new energy materials, filling the research gaps in related fields, and supporting the further development of SC technology.

Two-step extraction for the evaluation of metal-organic framework impregnated materials

Metal-organic frameworks (MOFs) are widely used for gas adsorption, separation, and sensing materials. In most cases, MOFs are not used in their crystal form but as impregnated materials because the fine crystals result in high-pressure drops. One key characteristic of MOF-impregnated materials is the amount of MOF in the material. This is evaluated using the wet digestion method; however, it is limited to determining only the metal content. Moreover, some metal, denoted as free metal, will not react with ligands to form MOFs. Additionally, it is crucial to determine the ligand amount, which cannot be determined using wet digestion. In the present study, a two-step extraction method for copper (II) benzene-1,3,5-tricarboxylate (Cu-BTC MOF) impregnated materials was developed to determine the MOF formed and free metals and ligands. Various solvents were applied to evaluate the extraction efficiencies. The results led to the selection of ethanol (EtOH) for extracting free Cu2+ and BTC, while 0.3 M HNO3 was chosen to extract MOF-formed Cu2+ and BTC. The MOF-impregnated sample material was first extracted using EtOH and then 0.3 M HNO3. The Cu2+ and BTC in the obtained extract solutions, as well as EtOH and HNO3, were analyzed using flame atomic absorption spectroscopy and high-performance liquid chromatography, respectively. In standard addition tests, free and MOF-formed Cu2+ and BTC were quantitatively extracted from MOF-impregnated materials. The developed two-step analysis method was successfully applied to Cu-BTC-impregnated materials used in gas sensing.

Theoretical investigation on the solid-liquid phase transition of gallium through free energy analysis

CONTEXT

Gallium, renowned for its notably low melting point and unique property of becoming liquid at room temperature, is a valuable constituent in phase change materials. In this study, we investigate the solid-liquid phase transition of gallium using the modified embedded atom method (MEAM) potential. It addresses the technique to compute the free energy difference between the solid and liquid without using a reference state. We examine various thermodynamic and dynamic properties, including density, specific heat capacity, diffusivity, and radial distribution functions. We compute the coexistence temperature of the solid-liquid phase transitions of gallium from free energy analysis. This information is crucial for understanding the behavior of the material under different pressure conditions and can be valuable for various applications, such as materials processing and high-pressure studies. The analysis, findings, and insights of the present work will be of great significance to the broad scientific and engineering communities in the field of phase transformation of materials.

METHODS

A series of molecular dynamics(MD) simulations were conducted using the LAMMPS software packages. The gallium atoms are modeled using the modified embedded atom method (MEAM) potential. To accurately predict the solid-liquid phase transitions of gallium, we calculated free energy by employing the "constrained λ integration" method, coupled with multiple histogram reweighting (MHR). The solid-liquid coexistence line is determined through the Gibbs-Duhem integration technique.

In situ growth of Zr-based metal-organic frameworks on cellulose sponges for Hg2+ and methylene blue removal

Metal-organic frameworks (MOFs) are characterised by high porosity levels and controllable structures, making them ideal adsorbents for wastewater. However, obtaining substrate materials with mechanical stability, excellent pore accessibility, and good processability for compositing MOF crystal powders to adsorb multiple pollutants in complex aqueous environments is challenging. In this study, porous MOFs@ modified cellulose sponge (MCS) composites were fabricated using MCS as a scaffold to provide anchoring sites for the coordination of Zr4+ ions and further in situ synthesis of MOFs, namely UiO-66@MCS and UiO-66-NH2@MCS, which effectively removed heavy metal ions and organic dyes. MOFs@MCS composites exhibit excellent water and dimensional stability, maintaining the pore structure by ambient drying during reuse. Compared with UiO-66@MCS composite, UiO-66-NH2@MCS composite exhibited a higher adsorption capacity of 224.5 mg·g-1 for Hg2+ and 400.9 mg·g-1 for methylene blue (MB). The adsorption of Hg2+ onto the MOFs@MCS composites followed the Langmuir and pseudo-second-order models, whereas the Freundlich and pseudo-second-order models were more suitable for MB adsorption. Moreover, the MOFs@MCS composites exhibited excellent reusability and were selective for the removal of Hg2+. Overall, this approach effectively combines Zr-based MOFs with mechanically and dimensionally stable porous cellulose sponges, rendering the approach suitable for purifying complex wastewater.

Support Platform of Functionalized Sustainable Cellulose Self-Entanglement Monolithic Adsorbents for Efficient Adsorption of Cadmium(II) Ions

Serious water contamination induced by massive discharge of cadmium(II) ions is becoming an emergent environmental issue due to high toxicity and bioaccumulation; thus, it is extremely urgent to develop functional materials for effectively treating with Cd2+ from wastewater. Benefiting from abundant binding sites, simple preparation process, and adjustable structure, UiO-66-type metal-organic frameworks (MOFs) had emerged as promising candidates in heavy metal adsorption. Herein, monolithic UiO-66-(COOH)2-functionalized cellulose fiber (UCLF) adsorbents were simply fabricated by incorporating MOFs into cellulose membranes through physical blending and self-entanglement. A two-dimensional structure was facilely constructed by cellulose fibers from sustainable biomass agricultural waste, providing a support platform for the integration of eco-friendly UiO-66-(COOH)2 synthesized with lower temperature and toxicity solvent. Structure characterization and bath experiments were performed to determine operational conditions for the maximization of adsorption capacity, thereby bringing out an excellent adsorption capacity of 96.10 mg/g. UCLF adsorbent holding 10 wt % loadings of UiO-66-(COOH)2 (UCLF-2) exhibited higher adsorption capacity toward Cd2+ as compared to other related adsorbents. Based on kinetics, isotherms, and thermodynamics, the adsorption behavior was spontaneous, exothermic, as well as monolayer chemisorption. Coordination and electrostatic attraction were perhaps mechanisms involved in the adsorption process, deeply unveiled by the effects of adsorbate solution pH and X-ray photoelectron spectroscopy. Moreover, UCLF-2 adsorbent with good mechanical strength offered a structural guarantee for the successful implementation of practical applications. This study manifested the feasibility of UCLF adsorbents used for Cd2+ adsorption and unveiled a novel strategy to shape MOF materials for wastewater decontamination.

Plasmonic photocatalytic nanocomposite of in-situ synthesized MnO2 nanoparticles on cellulosic fabric with structural color

The textile industry produces 20 % of the industrial water pollution containing toxic substances mostly dyes. Reducing material consumption and developing more efficient and scalable textile waste-water treatment methods such as photocatalytic degradation is essential. In this work, manganese dioxide nanoparticles (MnO2 NPs) were synthesized on the cotton fabric via a facile in-situ process. The preparation process was optimized for the highest photocatalytic activity under sunlight and color change originating from the plasmonic structural color of the nanoparticles. This promotes the photocatalytic activity by delocalization of the hot electrons while demonstrating the best washing and light fastness by using the least chemicals, and energy in a short time. In this way, the fabric was colored without any dye and possessed robust photocatalytic activity. Further, no dye-containing waste-water is made, and also accomplished to degrade dyes in a few hours under sunlight which is substantial for sustainable development. The treated fabrics indicated favorable mechanical properties, enhanced thermal stability, and perfect biocompatibility.

Physiochemical characterization of metal organic framework materials: A mini review

Metal-organic frameworks (MOFs) are promising materials offering exceptional performance across a myriad of applications, attributable to their remarkable physicochemical properties such as regular porosity, crystalline structure, and tailored functional groups. Despite their potential, there is a lack of dedicated reviews that focus on key physicochemical characterizations of MOFs for the beginners and new researchers in the field. This review is written based on our expertise in the synthesis and characterization of MOFs, specifically to provide a right direction for the researcher who is a beginner in this area. In this way, experimental errors can be reduced, and wastage of time and chemicals can be avoided when new researchers conduct a study. In this article, this topic is critically analyzed, and findings and conclusions are presented. We reviewed three well-known XRD techniques, including PXRD, single crystal XRD, and SAXS, which were used for XRD analysis depending on the crystal size and the quality of crystal morphology. The TGA profile was an effective factor for evaluating the quality of the activation process and for ensuring the successful investigation for other characterizations. The BET and pore size were significantly affected by the activation process and selective benzene chain cross-linkers. FTIR is a prominent method that is used to investigate the functional groups on pore surfaces, and this method is successfully used to evaluate the activation process, characterize functionalized MOFs, and estimate their applications. The most significant methods of characterization include the X-ray diffraction, which is utilized for structural identification, and thermogravimetric analysis (TGA), which is used for exploring thermal decomposition. It is important to note that the thermal stability of MOFs is influenced by two main factors: the metal-ligand interaction and the type of functional groups attached to the organic ligand. The textural properties of the MOFs, on the other hand, can be scrutinized through nitrogen adsorption-desorption isotherms experiments at 77 K. However, for smaller pore size, the Argon adsorption-desorption isotherm at 87.3 K is preferred. Furthermore, the CO2 adsorption isotherm at 273 K can be used to measure ultra-micropore sizes and sizes lower than these, which cannot be measured by using the N2 adsorption-desorption isotherm at 77 K. The highest BET was observed in high-valence MOFs that are constructed based on the metal-oxo cluster, which has an excellent ability to control their textural properties. It was found that the synthesis procedure (including the choice of solvent, cross-linker, secondary metal, surface functional groups, and temperature), activation method, and pressure significantly impact the surface area of the MOF and, by extension, its structural integrity. Additionally, Fourier-transform infrared spectroscopy plays a crucial role in identifying active MOF functional groups. Understanding these physicochemical properties and utilizing relevant characterization techniques will enable more precise MOF selection for specific applications.

Three-Dimensional Printing of Cellulose/Covalent Organic Frameworks (CelloCOFs) for CO2 Adsorption and Water Treatment

The development of porous organic polymers, specifically covalent organic frameworks (COFs), has facilitated the advancement of numerous applications. Nevertheless, the limited availability of COFs solely in powder form imposes constraints on their potential applications. Furthermore, it is worth noting that COFs tend to undergo aggregation, leading to a decrease in the number of active sites available within the material. This work presents a comprehensive methodology for the transformation of a COF into three-dimensional (3D) scaffolds using the technique of 3D printing. As part of the 3D printing process, a composite material called CelloCOF was created by combining cellulose nanofibrils (CNF), sodium alginate, and COF materials (i.e., COF-1 and COF-2). The intervention successfully mitigated the agglomeration of the COF nanoparticles, resulting in the creation of abundant active sites that can be effectively utilized for adsorption purposes. The method of 3D printing can be described as a simple and basic procedure that can be adapted to accommodate hierarchical porous materials with distinct micro- and macropore regimes. This technology demonstrates versatility in its use across a range of COF materials. The adsorption capacities of 3D CelloCOF materials were evaluated for three different adsorbates: carbon dioxide (CO2), heavy metal ions, and perfluorooctanesulfonic acid (PFOS). The results showed that the materials exhibited adsorption capabilities of 19.9, 7.4-34, and 118.5-410.8 mg/g for CO2, PFOS, and heavy metals, respectively. The adsorption properties of the material were found to be outstanding, exhibiting a high degree of recyclability and exceptional selectivity. Based on our research findings, it is conceivable that the utilization of custom-designed composites based on COFs could present new opportunities in the realm of water and air purification.

Fiber Integrated Metal-Organic Frameworks as Functional Components in Smart Textiles

Owing to high modularity and synthetic tunability, metal-organic frameworks (MOFs) on textiles are poised to contribute to the development of state-of-the-art wearable systems with multifunctional performance. While these composite materials have demonstrated promising functions in sensing, filtration, detoxification, and biomedicine, their applicability in multifunctional systems is only beginning to materialize. This review highlights the multifunctionality and versatility of MOF-integrated textile systems. It summarizes the operational goals of MOF@textile composites, encompassing sensing, filtration, detoxification, drug delivery, UV protection, and photocatalysis. Building upon these recent advances, this review concludes with an outlook on emerging opportunities for the diverse applications of MOF@textile systems in the realm of smart wearables.

Preparation of dopamine-modified sea squirt cellulose hydrogel dust-fixing agent to prevent raising of dust

Sea squirts, a tunicate, are found in all oceans and can foul marine ports and aquaculture, mainly affecting shipping and biodiversity. In this study, cellulose was extracted from sea squirts, and its hydrophilic properties were improved by substituting the hydrogen ions of the cellulose -OH with dopamine. The modified cellulose was used to prepare a hydrogel for use as a dust-fixing agent (CDP) to reduce air pollution caused by dust. After response surface method optimization, the proportions of binder, water-retaining agent, wetting agent, and antifreeze in CDP were 0.97, 1.44, 0.23, and 6.32%, respectively. This composition improved the wetting ability and permeability of CDP on particle surfaces. CDP exhibited good water retention at -11-50 °C. CDP reduced the wind erosion rate of dust at a wind speed of 12 m/s to 1.18%. The molecular dynamics method was used to analyze the wetting process and mechanism of CDP, revealing that hydrogen bonds were the dominant force at the solid-liquid interface. The adsorption of CDP onto the surface of coal increased the number of hydrophilic points. Water molecules were adsorbed on these hydrophilic points through hydrogen bonding, improving the binding energy between the solid and liquid interfaces. The application of ascidian cellulose in dust control makes full use of the biological value of ascidians, promoting sustainable development of the global biological economy.

Bionanocomposite based on immobilization of Burkholderia cepacian on GO/MOF and its removal of malachite green from river water

Bio-nanocomposites have attracted increasing research attention because they are able to integrate bio- and nano-related functions, and subsequently demonstrate potentially beneficial environmental applications. Here, a functional bionanomaterial based on Burkholderia cepacian (FZ) immobilized on GO/ZIF-8 was developed and used to remove malachite green (MG), with functions based on both biodegradation and adsorption. XRD and FTIR results showed that in situ production of GO/ZIF-8 by combining Zn2+ in ZIF-8 with the carboxyl group on the GO surface, led to FZ immobilized in GO/ZIF-8 through covalent bonding. Zeta analysis showed that the surface of FZ and GO/ZIF-8 had different charges under pH = 9.12, suggesting immobilization also occurred via electrostatic action. BET results confirmed that the specific surface area of GO/ZIF-8 was much larger than that of GO and ZIF-8, but the reduced specific surface area of FZ@GO/ZIF-8 could be due to FZ loading on its surface. The efficiency of FZ@GO/ZIF-8 in the removal of MG reached 99% and furthermore retained good stability after five cycles. The efficiency in removing multiple ions in river water reached more than 80%, which is evidence strongly suggesting that FZ@GO/ZIF-8 is an environmental bionanomaterial with effective application potential.

Catalytic ozonation of multi-VOCs mixtures over Cr-based bimetallic oxides catalysts from simulated flue gas: Effects of NO/SO2/H2O

Different Cr-based bimetallic oxides were prepared, and their catalytic performance was evaluated on the simultaneous removal of multi-VOCs mixtures (acetone, benzene, toluene, and o-xylene) by ozonation. Among them, Co-Cr catalyst stood out in catalytic ozonation of aromatic VOCs, and its activity on acetone conversion was promoted by raising the temperature and ozone concentrations, owing to lower crystallization, larger surface area, excellent redox and VOCs/CO2 desorption ability. Above 95% conversion of all multi-VOCs was achieved over the Co-Cr catalyst when the temperature was 100 °C and an excess ozone ratio λ (the ratio of actual moles of ozone to theoretical moles of ozone needed) was equal to 3. A competitive relationship was noticed during the removal process of four multiple VOCs, with significant inhibition of acetone conversion in the presence of aromatic VOCs, conceivably due to adsorption competition and byproducts accumulation. Effects of NO/SO2/H2O and respective reversibility were also investigated. The inhibition effects of NO/SO2/H2O on aromatic VOCs were far less than those on acetone. Further, the retarding effect of NO was reversible, attributing to physical adsorption competition, but the inhibition effect of SO2/H2O was irreversible, due to the blockage of active sites for VOCs removal. With the combination of scrubbing, multi-VOCs and NO/SO2 could be removed by catalytic ozonation simultaneously and efficiently. In-situ DRIFTS measurement was also conducted to investigate the adsorption and catalytic ozonation process of multi-VOCs mixtures, as well as under the presence of SO2/H2O, discovering the major intermediates, surface carboxylates and carboxylic acids.

Cellulose-based adsorbents for solid phase extraction and recovery of pharmaceutical residues from water

Cellulose has attracted interest from researchers both in academic and industrial sectors due to its unique structural and physicochemical properties. The ease of surface modification of cellulose by the integration of nanomaterials, magnetic components, metal organic frameworks and polymers has made them a promising adsorbent for solid phase extraction of emerging contaminants, including pharmaceutical residues. This review summarizes, compares, and contrasts different types of cellulose-based adsorbents along with their applications in adsorption, extraction and pre-concentration of pharmaceutical residues in water for subsequent analysis. In addition, a comparison in efficiency of cellulose-based adsorbents and other types of adsorbents that have been used for the extraction of pharmaceuticals in water is presented. From our observation, cellulose-based materials have principally been investigated for the adsorption of pharmaceuticals in water. However, this review aims to shift the focus of researchers to the application of these adsorbents in the effective pre-concentration of pharmaceutical pollutants from water at trace concentrations, for quantification. At the end of the review, the challenges and future perspectives regarding cellulose-based adsorbents are discussed, thus providing an in-depth overview of the current state of the art in cellulose hybrid adsorbents for extraction of pharmaceuticals from water. This is expected to inspire the development of solid phase exraction materials that are efficient, relatively cheap, and prepared in a sustainable way.

Cellulose/Zeolitic Imidazolate Framework (ZIF-8) Composites with Antibacterial Properties for the Management of Wound Infections

Metal-organic frameworks (MOFs) are a class of crystalline porous materials with outstanding physical and chemical properties that make them suitable candidates in many fields, such as catalysis, sensing, energy production, and drug delivery. By combining MOFs with polymeric substrates, advanced functional materials are devised with excellent potential for biomedical applications. In this research, Zeolitic Imidazolate Framework 8 (ZIF-8), a zinc-based MOF, was selected together with cellulose, an almost inexhaustible polymeric raw material produced by nature, to prepare cellulose/ZIF-8 composite flat sheets via an in-situ growing single-step method in aqueous media. The composite materials were characterized by several techniques (IR, XRD, SEM, TGA, ICP, and BET) and their antibacterial activity as well as their biocompatibility in a mammalian model system were investigated. The cellulose/ZIF-8 samples remarkably inhibited the growth of Gram-positive and Gram-negative reference strains, and, notably, they proved to be effective against clinical isolates of Staphylococcus epidermidis and Pseudomonas aeruginosa presenting different antibiotic resistance profiles. As these pathogens are of primary importance in skin diseases and in the delayed healing of wounds, and the cellulose/ZIF-8 composites met the requirements of biological safety, the herein materials reveal a great potential for use as gauze pads in the management of wound infections.

Nanostructured copper-organic frameworks for the generation of sulphate radicals: application in wastewater disinfection

In recent years, the presence of pathogens in the environment has become an issue of widespread concern in society. Thus, new research lines have been developed regarding the removal of pathogens and persistent pollutants in water. In this research, the efficacy of nanostructure copper-organic framework, HKUST-1, has been evaluated for its ability to eliminate Escherichia coli and generate sulphate radicals as catalyst for the treatment of effluents with a high microbiological load via peroxymonosulphate (PMS) activation. The disinfection process has been optimized, achieving complete elimination of Escherichia coli growth after 30 min of testing using a concentration of 60.5 mg/L HKUST-1 and 0.1 mM of PMS. To overcome the operational limitations of this system and facilitate its handling and reutilization in a flow disinfection process, HKUST-1 has been efficiently encapsulated on polyacrylonitrile as a novel development that could be scaled up to achieve continuous treatment.

Cellulose-Based Metallogels-Part 2: Physico-Chemical Properties and Biological Stability

Metallogels represent a class of composite materials in which a metal can be a part of the gel network as a coordinated ion, act as a cross-linker, or be incorporated as metal nanoparticles in the gel matrix. Cellulose is a natural polymer that has a set of beneficial ecological, economic, and other properties that make it sustainable: wide availability, renewability of raw materials, low-cost, biocompatibility, and biodegradability. That is why metallogels based on cellulose hydrogels and additionally enriched with new properties delivered by metals offer exciting opportunities for advanced biomaterials. Cellulosic metallogels can be either transparent or opaque, which is determined by the nature of the raw materials for the hydrogel and the metal content in the metallogel. They also exhibit a variety of colors depending on the type of metal or its compounds. Due to the introduction of metals, the mechanical strength, thermal stability, and swelling ability of cellulosic materials are improved; however, in certain conditions, metal nanoparticles can deteriorate these characteristics. The embedding of metal into the hydrogel generally does not alter the supramolecular structure of the cellulose matrix, but the crystallinity index changes after decoration with metal particles. Metallogels containing silver (0), gold (0), and Zn(II) reveal antimicrobial and antiviral properties; in some cases, promotion of cell activity and proliferation are reported. The pore system of cellulose-based metallogels allows for a prolonged biocidal effect. Thus, the incorporation of metals into cellulose-based gels introduces unique properties and functionalities of this material.

Gasoil removal from aqueous solution using magnetic metal-organic framework adsorbent based on the cellulosic fibrous of Prosopis farcta plant

Recently, the leakage of Gasoil and other petroleum substances into the seas, surface water, and wastewater has become a global problem; therefore, providing a solution to remove these pollutants seems vital. In the current research, we investigated the removal of floating Gasoil from aqueous solutions. First, the magnetic metal-organic framework was prepared as a new adsorbent based on the cellulosic fibrous of the Prosopis farcta plant (magnetic- cellulose@MIL-53(Fe) carbon aerogel). Using design of experiment, the effect of parameters pH, Gasoil concentration, and adsorbent weight on Gasoil removal were investigated. The adsorbent prepared under optimal parameters can remove 100% floating Gasoil from the aqueous solution. The adsorption capacity of the magnetic- cellulose@MIL-53 (Fe) carbon aerogel is 7.48 g.g-1, which is almost 100 times more than other Fe-based adsorbents. The study of the effect of time showed that the adsorption of Gasoil by the adsorbent is not dependent on time. Gasoil adsorption on magnetic- cellulose@MIL-53(Fe) carbon aerogel follows the Freundlich isotherm with a correlation coefficient of 0.9933. Thermodynamic factors Gibbs free energy, enthalpy, and entropy changes have been calculated. Accordingly, magnetic- cellulose @MIL-53(Fe) carbon aerogel has rapid separation and high stability, and it could be used as a good adsorbent to remove Gasoil from an aqueous solution. With good cycling stability of 86% retention of the initial adsorption value after ten adsorption/desorption cycles.

Novel sensor for the determination of CA 15-3 in serum of breast cancer patients based on Fe-gallic acid complex doped in modified cellulose polymer thin films

Fe-gallic acid MOF embedded in an epoxy methyl cellulose polymer (CMC) thin film was synthesized and characterized by different micro-analytical tools such as: FE-SEM/EDX, XPS analysis, XRD analysis, FT-IR, and fluorescence spectroscopy. Fe-gallic acid MOF doped in a stable CMC polymer thin film is used as a novel sensor to identify CA 15-3 in the sera of patients suffering breast malignancy. The presence of appropriate functional groups in aqueous CA 15-3 solutions enables it to interact with the Fe-gallic acid MOF embedded in the thin film. The Fe-gallic acid MOF was found to absorb energy at 350 nm (λex) and emits radiation at 439 nm which was specifically quenched in the presence of CA 15-3 over a working concentration range of 0.05-570 U mL-1. In contrast to other CA 15-3 detection methods which suffered from electronic noise, interference and slowness, the Fe-gallic acid MOF proved its sensitivity as an economic, stable and reliable probe for the detection and determination of CA 15-3 in patients' serum samples with a detection limit of 0.01 U mL-1 at pH 7.2.

An introductory review on advanced multifunctional materials

This review summarizes the applications of some of the advanced materials. It included the synthesis of several nanoparticles such as metal oxide nanoparticles (e.g., Fe₃O₄, ZnO, ZrOSO₄, MoO_3-x, CuO, AgFeO₂, Co₃O₄, CeO₂, SiO₂, and CuFeO₂); metal hydroxide nanosheets (e.g., Zn₅(OH)₈(NO₃)₂·2H₂O, Zn(OH)(NO₃)·H₂O, and Zn₅(OH)₈(NO₃)₂); metallic nanoparticles (Ag, Au, Pd, and Pt); carbon-based nanomaterials (graphene, graphene oxide (GO), graphitic carbon nitride (g-C₃N₄), and carbon dots (CDs)); biopolymers (cellulose, nanocellulose, TEMPO-oxidized cellulose nanofibers (TOCNFs), and chitosan); organic polymers (e.g. covalent-organic frameworks (COFs)); and hybrid materials (e.g. metal-organic frameworks (MOFs)). Most of these materials were applied in several fields such as environmental-based technologies (e.g., water remediation, air purification, gas storage), energy (production of hydrogen, dimethyl ether, solar cells, and supercapacitors), and biomedical sectors (sensing, biosensing, cancer therapy, and drug delivery). They can be used as efficient adsorbents and catalysts to remove emerging contaminants e.g., inorganic (i.e., heavy metals) and organic (e.g., dyes, antibiotics, pesticides, and oils in water via adsorption. They can be also used as catalysts for catalytic degradation reactions such as redox reactions of pollutants. They can be used as filters for air purification by capturing carbon dioxide (CO₂) and volatile organic compounds (VOCs). They can be used for hydrogen production via water splitting, alcohol oxidation, and hydrolysis of NaBH₄. Nanomedicine for some of these materials was also included being an effective agent as an antibacterial, nanocarrier for drug delivery, and probe for biosensing.

Green Nanomaterials for Smart Textiles Dedicated to Environmental and Biomedical Applications

Smart textiles recently reaped significant attention owing to their potential applications in various fields, such as environmental and biomedical monitoring. Integrating green nanomaterials into smart textiles can enhance their functionality and sustainability. This review will outline recent advancements in smart textiles incorporating green nanomaterials for environmental and biomedical applications. The article highlights green nanomaterials' synthesis, characterization, and applications in smart textile development. We discuss the challenges and limitations of using green nanomaterials in smart textiles and future perspectives for developing environmentally friendly and biocompatible smart textiles.

Electrochemical detection of ornidazole in commercial milk and water samples using an electrode based on green synthesis of silver nanoparticles using cellulose separated from Phoenix dactylifera seed

The widespread use of antibiotics has contributed to the control of disease and the nutritional well-being of livestock. Antibiotics reach the environment via excretions (urine and feces) from human and domestic animals, through non proper disposal or handling of unused drugs. The present study describes a green method for the synthesis of silver nanoparticle (AgNPs) using cellulose extracted from Phoenix dactylifera seed powder via mechanical stirrer method for the electroanalytical determination of ornidazole (ODZ) in milk and water samples. The cellulose extract is used as the reducing and stabilizer agent for the synthesis of AgNPs. The obtained AgNPs were characterized by UV-Vis, SEM and EDX, presenting a spherical shape and an average size of 48.6 nm. The electrochemical sensor (AgNPs/CPE) was fabricated by dipping a carbon paste electrode (CPE) in the AgNPs colloidal solution. The sensor shows acceptable linearity with ODZ concentration in the linear range from 1.0 × 10^-5 to 1.0 × 10^-3 M with a limit of detection (LOD =3S/P) and quantification (LOQ =10S/P) of 7.58 × 10^-7 M and 2.08 × 10^-6 M respectively.

Nanoparticle-Embedded Polymers and Their Applications: A Review

There has been increasing interest in the study and development of nanoparticle-embedded polymeric materials and their applications to special membranes. Nanoparticle-embedded polymeric materials have been observed to have a desirable compatibility with commonly used membrane matrices, a wide range of functionalities, and tunable physicochemical properties. The development of nanoparticle-embedded polymeric materials has shown great potential to overcome the longstanding challenges faced by the membrane separation industry. One major challenge that has been a bottleneck to the progress and use of membranes is the balance between the selectivity and the permeability of the membranes. Recent developments in the fabrication of nanoparticle-embedded polymeric materials have focused on how to further tune the properties of the nanoparticles and membranes to improve the performance of the membranes even further. Techniques for improving the performance of nanoparticle-embedded membranes by exploiting their surface characteristics and internal pore and channel structures to a significant degree have been incorporated into the fabrication processes. Several fabrication techniques are discussed in this paper and used to produce both mixed-matrix membranes and homogenous nanoparticle-embedded polymeric materials. The discussed fabrication techniques include interfacial polymerization, self-assembly, surface coating, and phase inversion. With the current interest shown in the field of nanoparticle-embedded polymeric materials, it is expected that better-performing membranes will be developed soon.

Nanoscale pores introduced into paper via mesoporous silica coatings using sol-gel chemistry

Mesopores, with diameters between 2 and 50 nm, not only increase the specific surface area, but also generate hierarchically porous materials with specific properties such as capillary fluid transport, ion specific pore accessibility, or size exclusion. Paper is a strongly hierarchical, porous material with specific properties, such as capillary force-driven fluid transport. However, paper fibers change their morphology during the initial step of wood disintegration. This results in changes of the porous fiber structure. In particular paper fibers loose their mesopores during the final drying step in the fabrication process. Here, we investigate silica mesopore formation in paper by sol-gel chemistry and evaporation induced self-assembly to specifically introduce and rationally design mesopore formation and distribution in cotton linter and eucalyptus sulfate paper sheets. We demonstrate the importance of synchronizing the solvent evaporation rate and capillary fluid velocity to ensure mesopore formation as well as the influence of the fiber type and sol-gel solution composition. The combination of argon and krypton sorption, SAXS, TEM and CLSM provides systematic analysis of the porous structure and the silica distribution along the cellulose paper fiber length and cross-section. These results provide a deeper understanding of mesopore formation in paper and how the latter is influenced by paper fluidic properties.

The accumulation and toxicity of ZIF-8 nanoparticles in Corbicula fluminea

Metal-organic frameworks (MOFs) are promising new materials that have been intensively studied and possibly applied to various environmental remediation. However, little is known about the fate and risk of MOFs to living organisms in the water environment. Here, the toxic effects of ZIF-8 nanoparticles (NPs) on benthic organisms were confirmed by sub-chronic toxicity experiments (7 and 14 days) using Corbicula fluminea as the model organism. With exposure doses ranging from 0 to 50 mg/L, ZIF-8 NPs induced oxidative stress behaviors similar to the hormesis effect in the tissues of C. fluminea. The oxidative stress induced by ZIF-8 NPs and the released Zn²⁺ was the crucial cause of the toxic effects. Besides, we also found that the ZIF-8 NPs and dissolved Zn²⁺ may result in different mechanisms of toxicity and accumulation depending on the dosages. The Zn²⁺ release rate of ZIF-8 NPs was high at low dosages, leading to a higher proportion of Zn²⁺ taken up by C. fluminea than the particulate ZIF-8. Conversely, at high dosages, C. fluminea mainly ingested the ZIF-8 NPs and resulted in increased mortality. The results have important implications for understanding the fate and biological effects of ZIF-8 in natural aquatic environments.

Metal organic framework-loaded polyethersulfone/polyacrylonitrile photocatalytic nanofibrous membranes under visible light irradiation for the removal of Cr(vi) and phenol from water

In this work, various amounts of the UiO-66-NH₂ and UiO-66-NH₂/TiO₂ MOFs have been loaded into polyacrylonitrile (PAN) nanofibers supported on polyethersulfone (PES). The visible light irradiation was used to investigate the influence of pH (2-10), initial concentration (10-500 mg L^-1), and time (5-240 min) on the removal efficiency of phenol and Cr(vi) in the presence of MOFs. The reaction time: 120 min, catalyst dosage: 0.5 g L^-1, pH: 2 for Cr(vi) ions and pH: 3 for phenol molecules were optimum to degrade phenol and to reduce Cr(vi) ions. The characterization of the produced samples was performed using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller analysis. The capability of synthesized photocatalytic membranes was investigated for the removal of phenol and Cr(vi) ions from water. The water flux, Cr(vi) and phenol solutions fluxes and their rejection percentages were evaluated under pressure of 2 bar in the presence of visible light irradiation and in the dark. The best performance of the synthesized nanofibers was obtained for UiO-66-NH₂/TiO₂ MOF 5 wt% loaded-PES/PAN nanofibrous membranes at temperature of 25 °C and pH of 3. Results demonstrated the high capability of MOFs-loaded nanofibrous membranes for the removal of various contaminants such as Cr(vi) ions and phenol molecules from water.

Advances in Application of Cellulose-MOF Composites in Aquatic Environmental Treatment: Remediation and Regeneration

Metal organic frameworks (MOFs) have gained remarkable interest in water treatment due to their fascinating characteristics, such as tunable functionality, large specific surface area, customizable pore size and porosity, and good chemical and thermal stability. However, MOF particles tend to easily agglomerate in nanoscale, thus decreasing their activity and processing convenience. It is necessary to shape MOF nanocrystals into maneuverable structures. The in situ growth or ex situ incorporation of MOFs into inexpensive and abundant cellulose-family materials can be effective strategies for the stabilization of these MOF species, and therefore can make available a range of enhanced properties that expand the industrial application possibilities of cellulose and MOFs. This paper provides a review of studies on recent advances in the application of multi-dimensional MOF-cellulose composites (e.g., aerogels, membranes, and bulk materials) in wastewater remediation (e.g., metals, dyes, drugs, antibiotics, pesticides, and oils) and water regeneration by adsorption, photo- or chemocatalysis, and membrane separation strategies. The advantages brought about by combining MOFs and cellulose are described, and the performance of MOF-cellulose is described and compared to its counterparts. The mechanisms of relative MOF-cellulose materials in processing aquatic pollutants are included. Existing challenges and perspectives for future research are proposed.

Cocatalyst loaded Al-SrTiO3 cubes for Congo red dye photo-degradation under wide range of light

The continued pollution, waste, and unequal distribution of the limited amount of fresh water on earth are pushing the world into water scarcity crisis. Consequently, development of revolutionary, cost-effective, and efficient techniques for water purification is essential. Herein, molten flux method was used for the preparation of micro-sized Al-doped SrTiO₃ photocatalyst loaded with RhCr₂O₃ and CoOOH cocatalysts via simple impregnation method for the photo-assisted degradation of Congo red dye under UV and visible irradiation compared with P25 standard photocatalyst. In addition, photoelectrochemical analysis was conducted to reveal the separation and transfer efficiency of the photogenerated e^-/h⁺ pairs playing the key role in photocatalysis. SEM and TEM analyses revealed that both P25 and the pristine SrTiO₃ have spherical shapes, while Al-doped SrTiO₃ and the sample loaded with cocatalysts have cubic shapes with a relatively higher particle size reaching 145 nm. In addition, the lowest bandgap is due to Al⁺³ ion doping and excessive surface oxygen vacancies, as confirmed by both UV-Vis diffuse-reflectance and XPS analyses. The loading of the cocatalysts resulted in a change in the bandgap from n-type (pristine SrTiO₃ and Al-SrTiO₃) into p-type (cocatalyst loaded sample) as exhibited by Mott-Schottky plots. Besides, the cocatalyst-loaded sample exhibited good performance stability after 5 cycles of the photocatalytic removal of Congo red dye. OH^· radical was the primary species responsible for CR degradation as confirmed by experiments with radical scavengers. The observed performance of the prepared samples under both UV and visible light could foster the ongoing efforts towards more efficient photocatalysts for water purification.

Metal-organic frameworks/cellulose hybrids with their modern technological implementation towards water treatment

Metal-organic frameworks (MOFs) are amongst the most attractive porous polymeric networks with appealing properties. However, their inherent fragility, powder nature, low processibility, and handling present some exceptional challenges for high-tech commercial applications. Currently, economic and environmental concerns drive the development of some bioinspired polymeric matrices containing MOFs. As an artifact, the availability of previously unattainable properties is negotiated by conjugating cellulosic materials with crystalline MOFs. Thus, multi-dimensional organic-inorganic hybrid composites are formed with high electrical, optical, mechanical, and thermal features. These MOF/cellulose hybrids, known as CelloMOFs (cellulose MOFs), have remarkable mechanical properties with tunable porosities, specific surface area and accessible active sites, making them ideal for real-world troubleshooting applications such as wastewater treatment, chemical sensing, energy storage, and so on. In this review, current state-of-the-art strategic synthesis routes for fabrication of MOF/cellulose composites with a specific focus on CelloMOFs as a potential tool for mitigation of the targeted emerging water contaminants have been done under the same umbrella, which has previously been less explored. Streamlining discussions on general properties such as raw material selection, structural analysis of cellulose, availability of surface functional groups, cellulose-metal node interactions, cellulose charging, and so on have been emphasized, as has integration with robust MOFs. A better understanding of these fundamental properties is critical because they will have a significant impact on the performance of MOF/cellulose composites in a variety of applications. Furthermore, at the end of this review, the challenges and perspectives of using CelloMOFs have been discussed in a concise manner in order to improve their practical utility rather than just concept mapping.

Cellulose Nanocrystals (CNCs) and Cellulose Nanofibers (CNFs) as Adsorbents of Heavy Metal Ions

The isolation of nanocellulose has been extensively investigated due to the growing demand for sustainable green materials. Cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs), which have the same chemical composition but have different morphology, particle size, crystallinity, and other properties depending on the precursor and the synthesis method used. In comparison, CNC particles have a short rod-like shape and have smaller particle dimensions when compared to CNF particles in the form of fibers. CNC synthesis was carried out chemically (hydrolysis method), and CNF synthesis was carried out mechanically (homogenization, ball milling, and grinding), and both can be modified because they have a large surface area and are rich in hydroxyl groups. Modifications were made to increase the adsorption ability of heavy metal ions. The Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric (TG), and dynamic light scattering (DLS) can reveal the characteristics and morphology of CNCs and CNFs. The success and effectiveness of the heavy metal adsorption process are influenced by a few factors. These factors include adsorbent chemical structure changes, adsorbent surface area, the availability of active sites on the adsorbent’s surface, adsorption constants, heavy metal ionic size differences, pH, temperature, adsorbent dosage, and contact time during the adsorption process. In this review, we will discuss the characteristics of CNCs and CNFs synthesized from various precursors and methods, the modification methods, and the application of CNCs and CNFs as heavy metal ion adsorbents, which includes suitable isotherm and kinetics models and the effect of pH on the selectivity of various types of heavy metal ions.

Cellulose: A Review of Water Interactions, Applications in Composites, and Water Treatment

Cellulose is known to interact well with water, but is insoluble in it. Many polysaccharides such as cellulose are known to have significant hydrogen bond networks joining the molecular chains, and yet they are recalcitrant to aqueous solvents. This review charts the interaction of cellulose with water but with emphasis on the formation of both natural and synthetic fiber composites. Covering studies concerning the interaction of water with wood, the biosynthesis of cellulose in the cell wall, to its dispersion in aqueous suspensions and ultimately in water filtration and fiber-based composite materials this review explores water-cellulose interactions and how they can be exploited for synthetic and natural composites. The suggestion that cellulose is amphiphilic is critically reviewed, with relevance to its processing. Building on this, progress made in using various charged and modified forms of nanocellulose to stabilize oil-water emulsions is addressed. The role of water in the aqueous formation of chiral nematic liquid crystals, and subsequently when dried into composite films is covered. The review will also address the use of cellulose as an aid to water filtration as one area where interactions can be used effectively to prosper human life.

3D printing of cellulose/leaf-like zeolitic imidazolate frameworks (CelloZIF-L) for adsorption of carbon dioxide (CO2) and heavy metal ions

Metal-organic frameworks (MOFs) have advanced several technologies. However, it is difficult to market MOFs without processing them into a commercialized structure, causing an unnecessary delay in the material's use. Herein, three-dimensional (3D) printing of cellulose/leaf-like zeolitic imidazolate frameworks (ZIF-L), denoted as CelloZIF-L, is reported via direct ink writing (DIW, robocasting). Formulating CelloZIF-L into 3D objects can dramatically affect the material's properties and, consequently, its adsorption efficiency. The 3D printing process of CelloZIF-L is simple and can be applied via direct printing into a solution of calcium chloride. The synthesis procedure enables the formation of CelloZIF-L with a ZIF content of 84%. 3D printing enables the integration of macroscopic assembly with microscopic properties, i.e., the formation of the hierarchical structure of CelloZIF-L with different shapes, such as cubes and filaments, with 84% loading of ZIF-L. The materials adsorb carbon dioxide (CO₂) and heavy metals. 3D CelloZIF-L exhibited a CO₂ adsorption capacity of 0.64-1.15 mmol g^-1 at 1 bar (0 °C). The materials showed Cu²⁺ adsorption capacities of 389.8 ± 14-554.8 ± 15 mg g^-1. They displayed selectivities of 86.8%, 6.7%, 2.4%, 0.93%, 0.61%, and 0.19% toward Fe³⁺, Al³⁺, Co²⁺, Cu²⁺, Na⁺, and Ca²⁺, respectively. The simple 3D printing procedure and the high adsorption efficiencies reveal the promising potential of our materials for industrial applications.

Collaboration of two-star nanomaterials: The applications of nanocellulose-based metal organic frameworks composites

Nanocellulose, as the star nanomaterial in carbohydrate polymers, has excellent mechanical properties, biodegradability, and easy chemical modification. However, further practical applications of nanocellulose are limited by their inadequate functionalization. Metal-organic frameworks (MOFs), as the star nanomaterial in functional polymers, have a large surface area, high porosity, and adjustable structure. The collaboration of nanocellulose and MOFs is a desirable strategy to make composites especially interesting for multifunctional and multi-field applications. What sparks will be produced by the collaboration of two-star nanomaterials? In this review article, we highlight an up-to-date overview of nanocellulose-based MOFs composites. The sewage treatment, gas separation, energy storage, and biomedical applications are mainly summarized. Finally, the challenges and research trends of nanocellulose-based MOFs composites are prospected. We hope this review may provide a valuable reference for the development and applications of carbohydrate polymer composites soon.

In situ growth of UiO-66-NH2 in wood-derived cellulose for iodine adsorption

The capture of radioactive iodine is an inevitable requirement in nuclear industry for environmental protection. Metal-organic frameworks (MOFs) are a new generation of sorbents that have wide applications for iodine adsorption and recovery. Although the loading of MOFs on wood can avoid the drawbacks of the powder form of MOFs in implementation, the dense structure of wood results in the lower loading, even after delignification, which limits the adsorption capacity. Herein, a hierarchically porous UiO-66-NH₂ @WCA composite was fabricated by in-situ synthesis of UiO-66-NH₂ in wood-derived cellulose aerogel (WCA) that was further removed hemicellulose from delignified wood. UiO-66-NH₂ @WCA exhibited a high loading (36 wt%) of UiO-66-NH₂ crystals and a high adsorption capacity of 704 mg/g for iodine vapor and 248 mg/g for iodine aqueous solution. The adsorption behavior in iodine aqueous solution was well predicted by the Freundlich isotherm and pseudo-second-order kinetic model. The adsorption capacity of UiO-66-NH₂ @WCA was highest in solution when the pH was 6, while the ionic strength had little effect. The hydroxyl groups on the WCA matrix had a charge transfer effect with iodine, providing additional sites for iodine capture. Furthermore, a packed column system was applied to demonstrate the excellent recyclability and potential for practical application.

Cellulose/inorganic nanoparticles-based nano-biocomposite for abatement of water and wastewater pollutants

Nanostructured materials offer a significant role in wastewater treatment with diminished capital and operational expense, low dose, and pollutant selectivity. Specifically, the nanocomposites of cellulose with inorganic nanoparticles (NPs) have drawn a prodigious interest because of the extraordinary cellulose properties, high specific surface area, and pollutant selectivity of NPs. Integrating inorganic NPs with cellulose biopolymers for wastewater treatment is a promising advantage for inorganic NPs, such as colloidal stability, agglomeration prevention, and easy isolation of magnetic material after use. This article presents a comprehensive overview of water treatment approaches following wastewater remediation by green and environmentally friendly cellulose/inorganic nanoparticles-based bio-nanocomposites. The functionalization of cellulose, functionalization mechanism, and engineered hybrid materials were thoroughly discussed. Moreover, we also highlighted the purification of wastewater through the composites of cellulose/inorganic nanoparticles via adsorption, photocatalytic and antibacterial approach.

A review of environmental friendly green composites: production methods, current progresses, and challenges

The growing concern about environmental damage and the inability to meet the demand for more versatile, environmentally friendly materials has sparked increasing interest in polymer composites derived from renewable and biodegradable plant-based materials, mainly from forests. These composites are mostly referred to as "green" and they can be widely employed in many industrial applications. Green composites are less harmful to the environment and could be potential substitutes for petroleum-based polymeric materials. It is helpful to limit usage of fossil oil assets by developing biopolymer matrices such as cellulose-reinforced biocomposites using renewable assets such as plant oils, carbohydrates, and proteins. This paper focuses on green composites processing utilizing a variety of naturally available resources, sustainable materials which are not detrimental to the environment, new scientific signs of progress in achieving green sustainable development, as well as nanotechnology and its environmental consequences. Additionally, the environmental impacts of different composite materials are examined in this paper, along with their production from eco-friendly materials. Moreover, the manufacturing aspects of green composites and some concerns related to their production are also discussed. The merits of green composite materials and valid reasons why they are a valuable substitute for the traditionally used composite materials are also covered.

Overview on recent advances of magnetic metal-organic framework (MMOF) composites in removal of heavy metals from aqueous system

Developing a novel, simple, and cost-effective analytical technique with high enrichment capacity and selectivity is crucial for environmental monitoring and remediation. Metal-organic frameworks (MOFs) are porous coordination polymers that are self-assembly synthesized from organic linkers and inorganic metal ions/metal clusters. Magnetic metal-organic framework (MMOF) composites are promising candidate among the new-generation sorbent materials available for magnetic solid-phase extraction (MSPE) of environmental contaminants due to their superparamagnetism properties, high crystallinity, permanent porosity, ultrahigh specific surface area, adaptable pore shape/sizes, tunable functionality, designable framework topology, rapid and ultrahigh adsorption capacity, and reusability. In this review, we focus on recent scientific progress in the removal of heavy metal ions present in contaminated aquatic system by using MMOF composites. Different types of MMOFs, their synthetic approaches, and various properties that are harnessed for removal of heavy metal ions from contaminated water are discussed briefly. Adsorption mechanisms involved, adsorption capacity, and regeneration of the MMOF sorbents as well as recovery of heavy metal ions adsorbed that are reported in the last ten years have been discussed in this review. Moreover, particular prospects, challenges, and opportunities in future development of MMOFs towards their greener synthetic approaches for their practical industrial applications have critically been considered in this review.

Recent advances in cellulose supported photocatalysis for pollutant mitigation: A review

In recent times, green chemistry or "green world" is a new and effective approach for sustainable environmental remediation. Among all biomaterials, cellulose is a vital material in research and green chemistry. Cellulose is the most commonly used natural biopolymer because of its distinctive and exceptional properties such as reproducibility, cost-effectiveness, biocompatibility, biodegradability, and universality. Generally, coupling cellulose with other nanocomposite materials enhances the properties like porosity and specific surface area. The polymer is environment-friendly, bioresorbable, and sustainable which not only justifies the requirements of a good photocatalyst but boosts the adsorption ability and degradation efficiency of the nanocomposite. Hence, knowing the role of cellulose to enhance photocatalytic activity, the present review is focused on the properties of cellulose and its application in antibiotics, textile dyes, phenol and Cr(VI) reduction, and degradation. The work also highlighted the degradation mechanism of cellulose-based photocatalysts, confirming cellulose's role as a support material to act as a sink and electron mediator, suppressing the charge carrier's recombination rate and enhancing the charge migration ability. The review also covers the latest progressions, leanings, and challenges of cellulose biomaterials-based nanocomposites in the photocatalysis field.

Fenton-like Cerium Metal–Organic Frameworks (Ce-MOFs) for Catalytic Oxidation of Olefins, Alcohol, and Dyes Degradation

A metal–organic framework (MOF) of cerium (Ce) ions and 4,4′,4′′-nitrilotribenzoic acid linker was synthesized via a hydrothermal method. Ce-MOF consists of a Lewis acid moiety, i.e. Ce3+ and triphenylamine cores. It showed Fenton-like properties with excellent catalytic oxidation activity for olefins, primary/secondary alcohols, and water pollutants e.g., organic dyes. It displayed high oxidation conversion of cinnamyl alcohol and styrene of 100% and 53%, respectively. It offered good selectivity towards styrene oxide and benzaldehyde (i.e. 75% and 100%, respectively). It was applied for the oxidative degradation of dyes e.g. rhodamine B (RhB), methyl blue (MeB), Congo red (CR), and direct blue (DB) using hydrogen peroxide (H2O2) as an oxidant. It exhibited high efficiency in the oxidative degradation of these water pollutants. The mechanistic study of oxidation involves the formation of radical hydroxyl (•OH) species. This study revealed the possibility of enhancing the oxidative catalytic performance, including oxidative degradation of organic pollutants, by employing advanced oxidation processes (AOPs) using Ce-MOF. The catalyst is recyclable five times without significantly decreasing of the material’s catalytic performance.

Covalent organic frameworks@ZIF-67 derived novel nanocomposite catalyst effectively activated peroxymonosulfate to degrade organic pollutants

Metal organic frameworks-Covalent organic frameworks (MOFs-COFs) nanocomposites could improve the catalytic performance. Herein, a novel nanocomposite catalyst (CC@Co₃O₄) derived from MOFs-COFs (COF@ZIF-67) was prepared on peroxymonosulfate (PMS) activation for bisphenol A (BPA) and rhodamine B (RhB) degradation. Owing to the Co species, oxygen vacancy (O_V), surface hydroxyl (-OH), graphite N and ketone groups (C=O), the CC@Co₃O₄ exhibited higher catalytic degradation performance and total organic carbon (TOC) for BPA (93.8% and 22.3%) and RhB (98.2% and 82.5%) with a small quantity of catalyst (0.10 g/L) and low concentration of PMS (0.20 g/L) even without pH adjustment. Sulfate radicals (•SO₄^-), hydroxyl radicals (•OH), single oxygen (¹O₂), superoxide radicals (•O₂^-) and electron transfer process were all involved in the degradation of BPA and RhB. Among them, the degradation of BPA and RhB mainly depended on •O₂^- and ¹O₂, respectively. Meanwhile, the degradation pathways of BPA and RhB were proposed, and the biotoxicity of the degradation products was evaluated by freshwater chlorella. The results illustrated that the degradation products were environmentally friendly to organisms. In addition, the role of COF in the nanocomposites was also studied. The addition of COF remarkably improved the catalytic performance of CC@Co₃O₄ due to the faster electron transfer, more graphite N and C=O. Overall, this work may open the door to the development of COF-based catalysts in the field of water pollutant remediation.

Application of bacterial nanocellulose decorated with zeolitic imidazolate framework (ZIF-L) as a platform for food freshness monitoring

Recently, the food freshness indicator (FFI) has garnered great interest from consumers and food producers. A novel FFI based on bacterial nanocellulose (BNC)/zeolitic imidazolate framework-L (ZIF-L) and grape anthocyanins was developed and characterized using field emission scanning electron microscopy, Fourier-transform infrared, X-ray diffraction, water contact angle, and BET techniques. The results confirmed that the BNC fibrils were decorated by in situ growth of ZIF-L, with a 3D flower-shaped structure and randomly multiple sharp-edged petals, and hydroxyl and oxygenated heterocycle aromatic ring functional groups on its surface. The reversibility, color stability performance, and moisture sorption of FFI were studied and its applicability in a two-layer arrangement as a visual freshness monitoring of shrimp and minced beef was evaluated. The FFI was able to distinguish (ΔE > 5) the fresh, medium fresh, and spoiled minced meat and shrimp visually during 10 and 4 days of storage at 4 °C, respectively. Also, monitoring of food chemical and microbiological parameters approved the correlation of food spoilage with the color parameters of FFI. These results confirmed the function of ZIF-L in the fabrication of highly pH-sensitive food intelligent packaging material.

Fabrication of Multifunctional Electronic Textiles Using Oxidative Restructuring of Copper into a Cu-Based Metal-Organic Framework

This paper describes a novel synthetic approach for the conversion of zero-valent copper metal into a conductive two-dimensional layered metal-organic framework (MOF) based on 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) to form Cu₃(HHTP)₂. This process enables patterning of Cu₃(HHTP)₂ onto a variety of flexible and porous woven (cotton, silk, nylon, nylon/cotton blend, and polyester) and non-woven (weighing paper and filter paper) substrates with microscale spatial resolution. The method produces conductive textiles with sheet resistances of 0.1-10.1 MΩ/cm², depending on the substrate, and uniform conformal coatings of MOFs on textile swatches with strong interfacial contact capable of withstanding chemical and physical stresses, such as detergent washes and abrasion. These conductive textiles enable simultaneous detection and detoxification of nitric oxide and hydrogen sulfide, achieving part per million limits of detection in dry and humid conditions. The Cu₃(HHTP)₂ MOF also demonstrated filtration capabilities of H₂S, with uptake capacity up to 4.6 mol/kg_MOF. X-ray photoelectron spectroscopy and diffuse reflectance infrared spectroscopy show that the detection of NO and H₂S with Cu₃(HHTP)₂ is accompanied by the transformation of these species to less toxic forms, such as nitrite and/or nitrate and copper sulfide and S_x species, respectively. These results pave the way for using conductive MOFs to construct extremely robust electronic textiles with multifunctional performance characteristics.

Tannic Acid as a Versatile Template for Silica Monoliths Engineering with Catalytic Gold and Silver Nanoparticles

Tannic acid in alkaline solutions in which sol-gel synthesis is usually performed with tetraethoxysilane is susceptible to various modifications, including formation of reactive radicals, oxidation under the action of atmospheric oxygen, self-association, and self-polymerization. Here, a precursor with ethylene glycol residues instead of ethanol was used, which made it possible to synthesize bionanocomposites of tannic acid and silica in one stage in neutral media under normal conditions without the addition of acid/alkali and organic solvents. Silica was fabricated in the form of optically transparent monoliths of various shapes with 2-4 nm pores, the radius of which well correlated with the size of a tannic acid macromolecule in a non-aggregated state. Polyphenol, which was remained in pores of silica matrix, served then as reducing agent to synthesize in situ gold and silver nanoparticles. As shown, these Au@SiO₂ and Ag@SiO₂ nanocomposites possessed localized surface plasmon resonance and high catalytic activity.