Employable metal (Ag & Pd)@MIL-125-NH2@cellulose acetate film for visible-light driven photocatalysis for reduction of nitro-aromatics

Anion vacancy engineered Cu/ZnIn2S4-VS/TiO2-VO S-scheme heterojunction for enhancing photocatalytic overall water splitting

Heterojunction materials for photocatalytic overall water splitting (POWS) become popular in recent times. However, even in the superior S-scheme heterojunction, the two semiconductor materials still do not have an efficient activity to separate and migrate photogenerated carriers. To further improve the charge separation and enhance the activity of POWS, a novel S-scheme heterojunction photocatalyst, Cu/ZnIn2S4-VS/TiO2-VO, was synthesized using solvothermal and calcination methods. The photocatalyst consists of Cu/ZnIn2S4 with sulfur vacancies (Cu/ZIS-VS) and TiO2 with oxygen vacancies (TiO2-VO). The resultant photocatalyst exhibited optimal hydrogen and oxygen evolution rates of 1245.3 μmol/g/h and 621.4 μmol/g/h, respectively. The apparent quantum efficiency reached 5.8 % at 365 nm. The corresponding characterization and theoretical calculations demonstrated the S-scheme heterojunction between Cu/ZIS-VS and TiO2-VO was successfully synthesized and resulted in a notable enhancement in the effective separation of carriers. Sulfur and oxygen vacancies in ZIS and TiO2, respectively, led to a reduction in their band gaps, which is beneficial for electron migration. Moreover, copper doping augmented the light absorption capabilities. Sulfur vacancies caused charge delocalization which facilitated the transfer of electrons and consequently enhanced the photocatalytic activity. This research provided an innovative perspective on the exploration and development of S-scheme heterojunctions aimed at POWS.

Water-Stable MIL-MOFs Developed Through a Novel Sacrifice-Protection Strategy Inspired by Butterfly Wings' Scales for Long-Term Turn-On Fluorescence Sensing of H2S

Metal-organic frameworks, which are the desired candidates for biosensing application due to their tunable properties, are significantly hindered by their rapid degradation in aqueous solutions, as well as the loss of their inherent fluorescence. Most studies aim to improve the hydrophobicity of materials by modifying their contact angle, thereby enhancing water stability. However, water droplets poorly adhere to the surface of hydrophobic materials, limiting their application for direct contact and detection in aqueous environments. Drawing inspiration from the sacrificial protection mechanism of butterfly wings used to evade predation and entanglement, a universal approach is successfully developed to protect water-sensitive MIL-MOFs from water molecule attack while preserving good hydrophilicity. Using the organic ligand 2,2'-bipyridine-5,5'-dicarboxylic acid (bpydc) as sacrificial protection scales, the MIL-125-NH2-bpydc demonstrated broad pH structural stability (pH 2-12) and fluorescence stability increased by 10.17 time in aqueous solutions, achieving the highest performance in MILMOFs. The MIL-125-NH2-bpydc is biocompatible enabling it to perform long-term fluorescence imaging in living cells and zebrafish, further detecting hydrogen sulfide (H2S) in the aqueous and biological systems via turn-on fluorescence emission. This study offers a novel and universal sacrifice-protection strategy for the design and development of the luminescent biocompatible MOFs tailored for biosensing applications.

Mechanism of cooperative migration and transformation of nitrobenzene and iron co-contaminated water and soil

Zero-valent iron (ZVI) has found extensive application in the remediation of contaminated soil and groundwater. However, it is essential to remain vigilant about its potential adverse impacts. This study is based on a real field pollution incident, supplemented by experimental simulations. A chemical plant's leakage of nitrobenzene and ZVI led to contamination at the site, with some of the nitrobenzene transforming into aniline, a compound with increased mobility and toxicity. The peak concentrations of nitrobenzene and aniline in the soil were recorded at 2710 mg/kg and 145 mg/kg, respectively. In groundwater, the highest concentrations of nitrobenzene and aniline reached 132 mg/L and 723 μg/L, respectively, exhibiting similar pollution plume distributions. Laboratory simulations were conducted to examine the transformation process of nitrobenzene in both aqueous and soil media in the presence of ZVI and its oxidation products. These investigations also explored the influence of various factors on the conversion of nitrobenzene and the yield of aniline. The column experiment methodology was employed to investigate the migration and transformation pathways of nitrobenzene in simulated media and actual field soils augmented with iron. Upon introducing iron powder, the maximum concentrations of aniline in quartz sand columns and silty clay columns were observed to be 694 mg/L and 1068 mg/L, respectively. During the reaction process, elemental iron primarily acted as a reductant, converting nitrobenzene to aniline, while being oxidized to Fe3O4 and γ-Fe2O3. This finding provides deeper insights into the mechanism underlying the synergistic transformation of iron and nitrobenzene within the contaminated site's aquifer.

Functionalization strategy of carboxymethyl cotton gauze fabrics with zeolitic imidazolate framework-67 (ZIF-67) as a recyclable material for biomedical applications

The accumulation of uremic toxins in the human body poses a deadly risk because it causes chronic kidney disease. To increase the effectiveness of hemodialysis and raise the survival rate, these toxins must be effectively removed from the bloodstream. Developing effective materials for removing these dangerous substances requires a thorough understanding of the interactions between an adsorbent and the uremic toxins. Thankfully, metal-organic frameworks (MOFs) have shown considerable promise for the identification and treatment of kidney disorders. Herein, cotton gauze fabrics (CGF) were carboxylated using monochloroacetic acid to produce carboxymethylated cotton gauze fabrics (CM-CGF). CM-CGF was subsequently decorated in situ with zeolitic imidazolate framework-67, resulting in carboxymethylated cotton gauze fabrics-zeolitic imidazolate framework-67 (CM-CGF-ZIF). The CGF, CM-CGF, and CM-CGF-ZIF were evaluated for potential kidney applications by removing uric acid and creatinine from mimic blood. The results showed that CM-CGF-ZIF had the highest adsorption of uric acid and creatinine. The maximum adsorption capacity of uric acid and creatinine was 164 and 222 mg/g for CM-CGF-ZIF, respectively, compared to 45 and 67 mg/g for CGF. CM-CGF-ZIF showed excellent antibacterial activity, good antifungal activity, low cytotoxicity, and a satisfactory level of blood compatibility.

Active site-exposed Bi2WO6@BiOCl heterostructures for photocatalytic hydrogenation of nitroaromatic compounds

Constructing heterostructured photocatalysts with highly exposed active sites proves to be an efficient strategy to improve the photocatalytic performance of bismuth-based photocatalysts. In this work, active site-exposed Bi2WO6@BiOCl (BWO@BOC) heterostructure composites based on two bismuth-based materials were fabricated by an in situ growth method for improving the photocatalytic hydrogenation of 4-aniline (4-NA) to p-phenylenediamine (PPD). BWO@BOC exhibited enhanced photoactivity for 4-NA hydrogenation compared to pure BWO and BOC. The optimal BWO@BOC composites displayed the highest conversion rate of 4-NA to PPD up to 99.3% within 12 min, with an apparent reaction rate constant of 0.414 min-1, which is 3.3 times that of pure BOC. The photoactivity enhancement is mainly ascribed to the construction of a tight Z-scheme heterostructure with improved light harvesting properties and charge carrier transport efficiency, which were revealed by optical and photoelectrochemical characterization, respectively. Furthermore, the products of the hydrogenation process were monitored by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to gain a better insight into the 4-NA hydrogenation mechanism.

Efficient adsorption of flavonoids on amino-functionalized ZIF-8/chitosan aerogels

Covalent organic structures (MOFs), known for their exceptional properties in separation and purification, have garnered significant attention. However, applying MOF-based adsorbents in complex flavonoid separation scenarios remains challenging. In this study, we successfully synthesized adsorbent materials capable of efficiently adsorbing flavonoids using a vacuum freeze-drying method. The materials were derived from a cross-linked chitosan aerogel functionalized with amino-substituted zeolite imidazolium ester skeleton (ZIF-8). The ZIF-8-NH2, synthesized via in situ substitution of 2-aminobenzimidazole within the ZIF-8 framework, exhibits a smaller pore size than mono ligand ZIF-8. Due to its synergistic interaction with chitosan's biocompatibility and porous structure, the aerogel material (ZIF-8-NH2/CS) exhibited outstanding adsorption capacities (183.37 mg/g, 226.34 mg/g, and 187.16 mg/g) in standard solutions (T = 318 K, rpm = 200) of luteolin, quercetin, and rutin, along with high adsorption rates (71.3 ± 2.3 %, 72.4 ± 1.4 %, and 70.7 ± 3.5 %). And showed rapid adsorption in the first 60 min. After 5 cycles, the adsorption capacity of ZIF-8-NH2/CS aerogel remained at 80.5 % of the adsorption capacity of the initial cycle, and therefore, ZIF-8-NH2/CS aerogel has a good potential for reusability. Additionally, the adsorption process adhered to pseudo-first-order and pseudo-second-order kinetic models, alongside Langmuir and Freundlich isothermal adsorption models. This study introduces novel ideas and methods for the extraction and separation of flavonoids. Furthermore, the developed ZIF-8-NH2/CS aerogels with amino functionality hold promise for diverse applications in separating and purifying bioactive substances.

Dual modification of reverse osmosis membranes with NH2-MIL-125 and functionalised multiwalled carbon nanotubes for enhanced nanoplastic removal

The present study describes a novel double-modified strategy for developing high-performance thin-film composite reverse osmosis (TFC-RO) membranes by incorporating titanium-based metal organic frameworks (NH2-MIL-125) and functionalised multiwalled carbon nanotubes (MWCNTs) into the support layer and selective layer, respectively. Initially, the support layer was subjected to successive modifications using NH2-MIL-125 mixed with polysulfone (PSF) in dimethylformamide DMF solution to investigate their impact on the performance and properties of the support layer and resultant TFC-RO membranes. Results indicated that the new structure of the modified support layer had significant influences on the developed TFC-RO membranes. Notably, the pristine PSF support exhibited a large surface pore size, medium porosity, and strong hydrophobicity, resulting in a low-flux TFC-RO membrane. However, after modification with NH2-MIL-125, the optimal blend support demonstrated a small surface pore size, high porosity, and improved hydrophilicity, favouring the formation of a high performance TFC-RO membrane. The incorporation of functionalised MWCNTs nanochannels into the selective layer, using the optimal NH2-MIL-125-PSF blended support, resulted in a smoother and more hydrophilic TFC-RO membrane with enhanced negative charge to improve antifouling properties against negative foulants (i.e., nanoplastics (NPs) and bovine serum albumin (BSA)). The double-modified membrane (TFC-RO-DM) exhibited superior performance over the conventional PSF-TFC-RO membrane. Notably, the maximum water flux reached 39 L m-2.h-1 with 98.4% NaCl rejection. The membrane exhibited a high flux recovery rate of 92% following a 30-min physical cleaning process. Additionally, the TFC-RO-DM membrane displayed reduced fouling against NPs suggesting the great promise of this innovative double-modification approach for the advancement of high-performance TFC-RO membranes.

Urea production via photocatalytic coupling of mixed gases (CO2/NH3) using Mo(MnO4)5 supported on Ce-BTC as nano-composite catalyst

Urea used in fertilization and feed supplement, as well as a starting material for the manufacture of plastics and drugs. Urea is most commonly produced by reacting carbon dioxide with ammonia at high temperature. Photocatalysis has gained attention as a sustainable pathway for performing urea. This work focus on designing very active photocatalysts based on cerium organic framework (Ce-BTC) doped with metal oxide nanoparticles (molybdenum permanganate, Mo(MnO4)5) for production of urea from coupling of ammonia with carbon dioxide. The prepared materials were characterized using different spectral analysis and the morphology was analysed using microscopic data. The effect of catalyst loading on the production rate of urea was investigated and the obtained results showed speed rate of urea production with high production yield at low temperature. The recyclability tests confirmed the sustainability of the prepared photocatlysts (Mo(MnO4)5@Ce-BTC) which supported the beneficial of the photocatalysis process in urea production.

Decoration of viscose fibers with silver nanoparticle-based titanium-organic framework for use in environmental applications

To effectively remove pharmaceuticals, nitroaromatic compounds, and dyes from wastewater, an efficient multifunctional material was created based on silver nanoparticles (Ag) and MIL-125-NH2 (MOF) immobilized on viscose fibers (VF) as a support substrate. Firstly, silver nanoparticles (Ag) were immobilized on the surface of viscose fibers (VF) via in situ synthesis using trisodium citrate (TSC) as a reducing agent to create (VF-Ag). Then, VF and VF-Ag were decorated with the titanium metal-organic framework MIL-125-NH2 (MOF) to create VF-MOF and VF-Ag-MOF. The influence of VF-Ag, VF-MOF, and VF-Ag-MOF on the sonocatalytic or sonophotocatalytic degradation of sulfa drugs was investigated. The results show that VF-Ag-MOF showed excellent sonocatalytic and sonophotocatalytic activity towards the degradation of sulfa drugs compared to VF-Ag and VF-MOF. Furthermore, sonophotodegradation showed a dramatic enhancement in the efficiency of degradation of sulfa drugs compared to sonodegradation. The sonophotodegradation degradation percentage of sulfanilamide, sulfadiazine, and sulfamethazine drugs in the presence of VF-Ag-MOF was 65, 90, and 95 after 45 min of ultrasonic and visible light irradiation. The catalytic activity of VF-Ag, VF-MOF, and VF-Ag-MOF was evaluated through the conversion of p-nitrophenol (4-NP) to p-aminophenol (4-AP). The results demonstrate that VF-Ag-MOF had the highest catalytic activity, followed by VF-Ag and VF-MOF. The conversion percentage of 4-NP to 4-AP was 69%. The catalytic or photocatalytic effects of VF-Ag, VF-MOF, and VF-Ag-MOF on the elimination of methylene blue (MB) dye were investigated. The results demonstrate that VF-Ag-MOF showed high efficiency in removing the MB dye through the reduction (65%) or photodegradation (71%) after 60 min. VF-Ag-MOF composites structure-activity relationships represent that doping within silver NPs enhanced the photocatalytic activity of MIL-125-NH2, which could be explained as follows: (i) Due to the formation of a Schottky barrier at the junction between MIL-125-NH2 and Ag NPs, the photogenerated electrons in the conduction band of MIL-125-NH2 were supposed to be quickly transferred to the valence band of the Ag NPs, and subsequently, the electrons were transferred to the conduction band of Ag NPs. This considerable electron transferring process, which is reported as Z scheme heterojunction, can efficiently suppress the recombination of electron/hole pairs in VF-Ag-MIL-125-NH2 composites. (ii) Sufficient separation between the photogenerated charge carriers (holes and electrons) and avoiding their recombination enhanced the photocatalytic activity of composites.

Spotlight on therapeutic efficiency of green synthesis metals and their oxide nanoparticles in periodontitis

Periodontitis, one of the most prevalent dental diseases, causes the loss of bone and gum tissue that hold teeth in place. Several bacteria, commonly present in clinically healthy oral cavities, may induce and perpetuate periodontitis when their concentration rises in the gingival sulcus. Antibacterial effect against various Gram-negative and Gram-positive bacteria, including pathogenic and drug-resistant ones, has been shown for several distinct transient metal and metal oxide NPs. Therefore, NPs may be used in biomedicine to treat periodontal problems and in nanotechnology to inhibit the development of microorganisms. Instead of using harmful chemicals or energy-intensive machinery, biosynthesis of metal and metal oxide nanoparticles (NPs) has been suggested. To produce metal and metal oxide NPs, the ideal technique is "Green" synthesis because of its low toxicity and safety for human health and the environment. Gold NPs (AuNPs) appear to be less toxic to mammalian cells than other nanometals because their antibacterial activity is not dependent on reactive oxygen species (ROS). AgNPs also possess chemical stability, catalytic activity, and superior electrical and thermal conductivity, to name a few of their other advantageous characteristics. It was observed that zinc oxide (ZnO) NPs and copper (Cu) NPs exhibited discernible inhibitory effects against gram-positive and gram-negative bacterial strains, respectively. ZnO NPs demonstrated bactericidal activity against the microorganisms responsible for periodontitis. Medications containing magnetic NPs are highly effective against multidrug-resistant bacterial and fungal infections. The titanium dioxide (TiO2) NPs are implicated in elevating salivary peroxidase activity in individuals diagnosed with chronic periodontitis. Furthermore, specific metallic NPs have the potential to enhance the antimicrobial efficacy of periodontitis treatments when combined. Therefore, these NPs, as well as their oxide NPs, are only some of the metals and metal oxides that have been synthesized in environmentally friendly ways and shown to have therapeutic benefits against periodontitis.

Selective separation of chlorophyll-a using recyclable hybrids based on Zn-MOF@cellulosic fibers

Chlorophyll-a as pigments, exist in the green organelles for plants that act in photosynthesis. Different studies were considered with demonstration of an effective separation technique of Chlorophyll-a without decomposition; however, the reported methods were disadvantageous with expensiveness and low quantum yield. The current work uniquely represents an investigative method for the separation of Chlorophyll-a from spinach extract using cellulosic hybrids based on ZIF-8 @cellulosic fibers (Zn-zeolitic imidazolate frameworks@cellulosic fibers) as a cost effective and recyclable absorbents. To obtain hybrids, ZIF-8 was in-situ prepared over the cellulosic fibers (bamboo, modal and cotton). The untreated and treated fibers were well characterized via FTIR, SEM, EDX, XRD, in order to approve the successive impregnation of ZIF-8. Whereas, the microscopic images showed that, microcrystalline ZIF-8 rods with length of 1.3-4.4 µm were grown over the cellulosic fibers. The obtained hybrids and the untreated fibers were exploited in the separation of Chlorophyll-a via the adsorption/desorption process. The chlorophyll-adsorption was followed Langmuir isotherm and pseudo-second order model. The Langmuir maximum capacities of Chlorophyll-a onto hybrids were followed the order of ZIF-8@cotton (583.6 mg/g) > ZIF-8@modal (561.3 mg/g) > ZIF-8@bamboo (528.7 mg/g). After incorporation of ZIF-8, the maximum adsorption capacities of cellulosic fibers were enhanced by 1.4-1.9 times. Adsorption of chlorophyll onto the applied hybrids was lowered by 27-28%, after five repetitive washing cycles. The data summarized that; chlorophyll was effectively separated by the synthesized ZIF-8@cellulosic fibers hybrids, whereas, the prepared hybrids showed good reusability for application on wider scaled purposes.

Construction of BiOCl/Ti-MOFs type-II heterojunction photocatalyst for enhanced photocatalytic performance for multiple antibiotics removal

The increased threats to environmental and human health caused by the widespread use of antibiotics have increased the need for efficient technologies for removing antibiotic remnants from wastewater after production. Photocatalysis, which is non-toxic, highly efficient, and low energy consumption, has played a vital role in wastewater treatment among the aforementioned technologies. Therefore, a MIL-125(Ti)/BiOCl type-II heterojunction photocatalyst was fabricated using solvothermal method. Investigations remarkably revealed that the enhanced photocatalytic performance of the photocatalyst for multiple antibiotics degradation (tetracycline and ofloxacin) was attributed to the construction of a heterojunction, which inhibits carrier recombination and enhances visible-light absorption. Furthermore, the radical trapping experiments and electron spin resonance determined superoxide radicals and holes to be the main species in the photocatalytic process. Finally, we presented a potential photocatalytic mechanism that could account for the observations. Overall, this study offered guidelines for developing more photocatalysts with visible-light responses and removing multiple antibiotics from water more efficiently.

Ag-Doped Metal-Organic Frameworks' Heterostructure for Sonodynamic Therapy of Deep-Seated Cancer and Bacterial Infection

Metal-organic frameworks (MOF) have attracted great potential in sonodynamic therapy (SDT) owing to large sonosensitizers' loading and fast reactive oxygen species' (ROS) diffusion; however, the low ligand-to-metal charge transfer efficiency sharply impairs the SDT effect. Herein, we report the design of MIL@Ag heterostructures with high electron-hole pairs separation efficiency and enhanced diverse ROS generation ability for deep-seated cancer treatment and bacterial infection. The MIL@Ag heterostructure is composed of Ti-based MOFs (named MIL), on which are in situ assembled silver nanoparticles (Ag NPs). The electrochemical experiments and density functional theory calculations verify that the introduction of Ag NPs can significantly improve the electron transfer efficiency and O2 adsorption capacity of MIL. Under ultrasound irradiation, the doped Ag NPs can trap the activated electrons from MIL to reduce surrounding O2 and produce superoxide radicals (•O2-), while the activated holes enable oxidizing H2O to produce hydroxyl radicals (•OH). Thus, they efficiently improve the therapeutic efficiency of SDT. MIL@Ag-PEG-mediated SDT implements A549 cancer cells' killing under a tissue barrier of 2 cm and eradicates the bacterial infection of Staphylococcus aureus, thus promoting wound healing. Therefore, MIL@Ag-PEG provides a promising strategy for augmenting SDT performance by rational heterostructure design of sonosensitizers.

Affinity of carbon quantum dots anchored within metal organic framework matrix as enhancer of plant nourishment

Nano-fertilizers were ascribed to be significantly advantageous with minimizing the negative effects of requiring excessive contents in the soil and reducing the number of times for fertilization. Herein, the superior affinity of carbon quantum dots (CQDs) anchored within metal organic framework (Cu-BTC) matrix was investigated for the first time as a fertilizer for sunflower. CQDs were nucleated from alkali-hydrolyzed carboxymethyl cellulose (CMC) via the hydrothermal technique. The synthesized CQDs (6.8 ± 3.7 nm) were anchored within Cu-BTC (crystalline rod-like structure) matrix, to produce CQDs@Cu-BTC composite. The obtained CQDs and CQDs@Cu-BTC were applied as nutrients for the sunflower plant. The chlorophyll a and carotenoids contents were 0.465 & 0.497 and 0.350 & 0.364 mg/g after treatment with CQDs & CQDs@Cu-BTC, respectively. The shoot length of sunflower sample was increased after feeding with CQDs and CQDs@Cu-BTC to be 38.7 and 46.5 cm, respectively. The obtained results confirmed that, the synthesized CQDs@Cu-BTC showed superiority as nutrient material via enhancing the growth and physiological properties of sunflower and consequently could be used as fertilizer for plants instead of the commercial nutrient.

Recent Progress on Tailoring the Biomass-Derived Cellulose Hybrid Composite Photocatalysts

Biomass-derived cellulose hybrid composite materials are promising for application in the field of photocatalysis due to their excellent properties. The excellent properties between biomass-derived cellulose and photocatalyst materials was induced by biocompatibility and high hydrophilicity of the cellulose components. Biomass-derived cellulose exhibited huge amount of electron-rich hydroxyl group which could promote superior interaction with the photocatalyst. Hence, the original sources and types of cellulose, synthesizing methods, and fabrication cellulose composites together with applications are reviewed in this paper. Different types of biomasses such as biochar, activated carbon (AC), cellulose, chitosan, and chitin were discussed. Cellulose is categorized as plant cellulose, bacterial cellulose, algae cellulose, and tunicate cellulose. The extraction and purification steps of cellulose were explained in detail. Next, the common photocatalyst nanomaterials including titanium dioxide (TiO2), zinc oxide (ZnO), graphitic carbon nitride (g-C3N4), and graphene, were introduced based on their distinct structures, advantages, and limitations in water treatment applications. The synthesizing method of TiO2-based photocatalyst includes hydrothermal synthesis, sol-gel synthesis, and chemical vapor deposition synthesis. Different synthesizing methods contribute toward different TiO2 forms in terms of structural phases and surface morphology. The fabrication and performance of cellulose composite catalysts give readers a better understanding of the incorporation of cellulose in the development of sustainable and robust photocatalysts. The modifications including metal doping, non-metal doping, and metal-organic frameworks (MOFs) showed improvements on the degradation performance of cellulose composite catalysts. The information and evidence on the fabrication techniques of biomass-derived cellulose hybrid photocatalyst and its recent application in the field of water treatment were reviewed thoroughly in this review paper.

Preparation and characterization of novel Niln2S4/UiO-66 photocatalysts for the efficient degradation of antibiotics in water

Photocatalysis is considered an economical, environmentally friendly, and effective technology for removing pollutants. The construction of Z-Scheme heterojunctions has been identified as one of the feasible solutions capable of enhancing the photocatalytic activity. Herein, a series of visible light responsive photocatalysts (NiIn₂S₄/UiO-66 composites) with excellent activity and stability were prepared by using a solvothermal process. It is found that 20 mg L^-1 of tetracycline (TC) could be almost completely degraded under visible light irradiation within 1 h, when the mass ratio of NiIn₂S₄ to UiO-66 is 0.5:1 (NISU-0.5) and the solution pH = 11. In addition, after six cycles, the degradation rate of tetracycline photocatalyzed by NISU-0.5 still reach up to 90%. Ultraviolet photoelectron spectra (UPS), X-ray photoelectron spectra (XPS) and electron spin resonance measurements (ESR) confirm the formation of the Z-Scheme heterostructure between NiIn₂S₄ and UiO-66. The synergistic effect between built-in electric field, energy band bending and coulomb interactions in interface of Z-Scheme heterojunction is conducive to restrain the recombination of photogenerated electrons and holes, which greatly improve the photocatalytic activity. In conclusion, this study offers a new thought for design and synthesis of Z-Scheme heterojunctions and provides a cost-effective strategy for solving environmental pollution and energy problems in the future.

Cellulose-Derived Carbon Dot-Guided Growth of ZnIn2 S4 Nanosheets for Photocatalytic Oxidation of 5-Hydroxymethylfurfural into 2,5-Diformylfuran

Cellulose-derived carbon (CC) dot-directed growth of ZnIn₂ S₄ was achieved through hydrothermal treatment of carboxylated cellulose followed by in situ growth of ZnIn₂ S₄ nanosheets. The carbon dots inherited from carboxylated cellulose equip plenty of surface carboxyl groups, which induce the ionic interaction with Zn²⁺ and In³⁺ and the guided growth of ZnIn₂ S₄ . As a result, the nanosheets of ZnIn₂ S₄ are evenly and intimately grown on the small carbon dots, providing high-speed channels for charges transfer. In conjunction with the reinforced visible-light capture and good conductivity of carbon dots, the resultant CC/ZnIn₂ S₄ shows an outstanding photocatalytic activity. As a proof-of-concept, visible-light-driven 5-hydroxymethylfurfural oxidation into 2,5-diformylfuran was conducted. The evolution of 2,5-diformylfuran over the optimal CC/ZnIn₂ S₄ sample can reach ∼2980 μmol g^-1 , about 3.4 times that of pristine ZnIn₂ S₄ . Additionally, the apparent quantum yield could attain 3.4 % at a wavelength of 400 nm.

Photocatalytic Multielectron Reduction of Nitroarenes to Anilines by Utilizing an Electron-Storable Polyoxometalate-Based Metal-Organic Framework

A powerful approach to generate photocatalysts for the highly selective reduction of nitrobenzene using light as the driving force is a combination of photosensitizers and electron-storable components in a cooperative photocatalysis fashion. Herein, a new precious metal-free photocatalyst, {ZnW-TPT}, was prepared by incorporating a Zn-substituted monovacant Keggin polyanion [SiZnW₁₁O₃₉]^6- and a photoactive organic bridging link 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) into a framework. In this structure, the direct coordination bond between [SiZnW₁₁O₃₉]^6- and the TPT ligand and the π-π interactions between TPT molecules help separate and migrate photogenerated carriers, which improves the photocatalytic activity of {ZnW-TPT}. The photoelectrochemical properties of {ZnW-TPT} were well studied by solid UV-vis absorption, fluorescence, transient photocurrent response, and electrochemical impedance spectroscopy tests. {ZnW-TPT} efficiently converts using hydrazine hydrate with 99% conversion and 99% selectivity for anilines under mild conditions.

Carbon Quantum Dots-Based Fluorescent Hydrogel Hybrid Platform for Sensitive Detection of Iron Ions

In this study, we prepared novel fluorescent carbon quantum dots/hydrogel nanocomposite material (CQDsHG) with good adsorption and stable fluorescence detection of Fe3+. The materials were subsequently characterized according to their morphological features, chemical composition, adsorption, and optical properties. The carbon quantum dots (CQDs) were prepared using a microwave-assisted hydrothermal method in no more than 15 min, and the as-prepared CQDs exhibited excellent water solubility, as well as emitted strong bright blue fluorescence with an ultrahigh quantum yield of 93.60%. The CQDs were then loaded into a hydrogel (HG) using the sol-gel method to obtain a functional CQDsHG. The CQDsHG exhibited high adsorption amounts (31.94 mg/g) and a good quenching response for Fe3+, thus, it could be used as a sensor to selectively detect Fe3+ in the linear range of 0–150 μM with a detection limit of 0.24 μM. We observed minimal difference in the fluorescence lifetimes between the CQDsHG with and without a quencher (Fe3+), with values of 5.816 ns and 5.824 ns, respectively, confirming that Fe3+ was statically quenched on CQDsHG. The results indicated that the innovative combination of CQDs and HG can improve the synergistic performance of each component for the adsorption and quantitative detection of heavy metal ions in the aqueous environment.

The Potential Application of Green-Synthesized Metal Nanoparticles in Dentistry: A Comprehensive Review

Orodental problems have long been managed using herbal medicine. The development of nanoparticle formulations with herbal medicine has now become a breakthrough in dentistry because the synthesis of biogenic metal nanoparticles (MNPs) using plant extracts can address the drawbacks of herbal treatments. Green production of MNPs such as Ag, Au, and Fe nanoparticles enhanced by plant extracts has been proven to be beneficial in managing numerous orodental disorders, even outperforming traditional materials. Nanostructures are utilized in dental advances and diagnostics. Oral disease prevention medicines, prostheses, and tooth implantation all employ nanoparticles. Nanomaterials can also deliver oral fluid or pharmaceuticals, treating oral cancers and providing a high level of oral healthcare. These are also found in toothpaste, mouthwash, and other dental care products. However, there is a lack of understanding about the safety of nanomaterials, necessitating additional study. Many problems, including medication resistance, might be addressed using nanoparticles produced by green synthesis. This study reviews the green synthesis of MNPs applied in dentistry in recent studies (2010–2021).

Single-step Synthesis and Characterization of Zr-MOF onto Wool Fabric: Preparation of Antibacterial Wound Dressing with High Absorption Capacity

Improvement of curative herbal extracts effectiveness through novel drug delivery systems is a field of study for the researches nowadays. Zirconium-based metal-organic frameworks (Zr-MOFs) are one of the most capable porous nanocarriers that need a biocompatible template to be used in biomedical applications. In this work, Zr-MOF was synthesized into the wool fabric through in-situ one-pot method with different molar ratios. The final fabrics were characterized thoroughly using various techniques and the effect of components on monodispersity and nucleation tendency of Zr-MOF onto the surface of wool were explained. The resultant fabric stablished absolute wash durability, increased air-permeability up to twice and reasonable hydrophilicity. Tensile strength and young modulus decreased 30 and 1244 % and strain increased 66 %. Salvia Officinalis (SO) and Calendula Officinalis (CO) extracts were loaded onto the modified fabrics with 1154 and 1842 % increased absorption capacity. The release profiles showed domination of diffusion mechanism. The wool-MOF-SO and CO displayed both 100 % antibacterial activity against Escherichia coli and 60.95 and 64.64 % against Staphylococcus aureus because of diverse antibacterial components. Calendula Officinalis proved biocompatibility with human skin however Salvia Officinalis exhibited high toxicity.

Pore-size control of chitin nanofibrous composite membrane using metal-organic frameworks

Herein, environmentally benign chitin nanofiber (ChNF) membranes were fabricated by regulating suspension behavior. The introduction of zeolitic imidazole frameworks (ZIF-8) into the composite membranes led to the domain formation of ChNF derived by coordinative interaction, resulting in pore size-tunable membranes. Based on the rheological, morphological, and structural characterizations, the driving force of pore-size control was studied in the aqueous suspension of ChNF and ZIF-8 according to the relative concentration. At critical concentration, the 30-ChNF membrane presents superior water permeance (40 LMH h^-1) while maintaining a high rejection rate (>80% for all organic dyes). Moreover, the molecular size cut-off of the composite membranes for dyes can be controlled in the range of less than 1 nm to 2 nm. The experimental results provide a simple strategy for the preparation of pore tunable ChNF membranes using MOF with high mechanical strength, good durability, high flux, dye rejection, and antifouling ability.

A new 3D 8-connected Cd(ii) MOF as a potent photocatalyst for oxytetracycline antibiotic degradation

1 exhibits the best photocatalytic decomposition efficiency towards antibiotic OXY. The plausible photocatalytic mechanism has been explained with the help of the density of states calculations and Hirshfeld surface analysis.

In Search of Effective UiO-66 Metal-Organic Frameworks for Artificial Kidney Application

The removal of uremic toxins from patients with acute kidney injury is a key issue in improving the quality of life for people requiring peritoneal dialysis. The currently utilized method for the removal of uremic toxins from the human organism is hemodialysis, performed on semipermeable membranes where the uremic toxins, along with small molecules, are separated from proteins and blood cells. In this study, we describe a mixed-linker modulated synthesis of zirconium-based metal-organic frameworks for efficient removal of uremic toxins. We determined that the efficient adsorption of uremic toxins is achieved by optimizing the ratio between -amino functionalization of the UiO-66 structure with 75% of -NH2 groups within organic linker structure. The maximum adsorption of hippuric acid and 3-indoloacetic acid was achieved by UiO-66-NH2 (75%) and by UiO-66-NH2 (75%) 12.5% HCl prepared by modulated synthesis. Furthermore, UiO-66-NH2 (75%) almost completely adsorbs 3-indoloacetic acid bound to bovine serum albumin, which was used as a model protein to which uremic toxins bind in the human body. The high adsorption capacity was confirmed in recyclability test, which showed almost 80% removal of 3-indoloacetic acid after the third adsorption cycle. Furthermore, in vitro cytotoxicity tests as well as hemolytic activity assay have proven that the UiO-66-based materials can be considered as potentially safe for hemodialytic purposes in living organisms.

Melt intercalation technique for synthesis of hetero-metallic@chitin bio-composite as recyclable catalyst for prothiofos hydrolysis

The compatibility of homo-metallic and hetero-metallic bio-composite was promisingly investigated as recyclable catalyst for prothiofos hydrolysis. Chitin as water insoluble biopolymer was functionalized as a template for generation of homo-metallic (Ag@chitin, Au@chitin and Pd@chitin) and hetero-metallic (Au@Ag@chitin, Pd@Ag@chitin and Pd@Au@Ag@chitin) composites, by using melt intercalation technique. Investigation of the compatibility of the synthesized homo-metallic and hetero-metallic bio-composites in hydrolysis of prothiofos was performed and affirmed via HPLC results. Immobilization of Pd in the composites showed perfection in the catalytic performance for prothiofos hydrolysis. Pd@Au@Ag@chitin exhibited the highest hydrolysis result of 99% for prothiofos was hydrolyzed within 150 min with rate constant (k₁) of 24.48 min^-1. After five recycles for Pd@Au@Ag@chitin, the hydrolysis of prothiofos was lowered from 346 mg/g to 269 mg/g with reduction percentage of 22%. The synthesized bio-composite was highly effective as recyclable catalyst and can be easily served in the remediation of pesticides.