Search Results (2,013)

Metal–organic frameworks (MOFs) are unique microporous materials being explored for a wide range of applications. Their porosity and high surface areas can readily be exploited for guest–host interactions, separations, and photochemical catalysis, but many suffer from poor charge separation and fast electron–hole recombination. Introducing structural defects, such as missing linkers or metal nodes, can create unsaturated metal sites and alter band structure, conductivity, and light absorption, improving photocatalytic performance. UiO-66-NH₂ and MIL-125-NH₂ are water-stable, visible-light-absorbing MOFs well suited for photocatalytic degradation of organic dyes. In this work, the influence of defect engineering on photocatalytic properties of MOFs was investigated using formic and acetic acid modulators with UiO-66-NH₂ and variable temperature with MIL-125-NH₂ during synthesis. The resulting materials were characterized by XRD, FTIR and SEM/EDS. Defect states were tracked using N₂ adsorption/BET analysis and UV–Vis spectroscopy. Photocatalytic activity was evaluated by monitoring Rhodamine B (RhB) degradation in aqueous solution under simulated solar irradiation. It was found that increased temperature beyond 120 °C during synthesis promotes mesopore formation and decreases the bandgap in MIL-125-NH₂, resulting in a more photoactive material. Defective MIL-125-NH₂ synthesized at 150 °C showed the most defects and proved to be the best photocatalyst investigated in this study. Formic acid modulation in UiO-66-NH₂ generated smaller crystallites that slightly increased the bandgap; however, the surface area decreased proportionally with the amount of formic acid used. The decreased surface area and observed enhancement in photocatalytic degradation of RhB suggest that formic acid introduces defects into the UiO-66-NH₂ framework that enhance photocatalytic properties. UiO-66-NH₂ treated with acetic acid resulted in larger crystals, increased bandgaps, and increased surface areas, suggesting that acetic acid simply modulates growth rather than imparting defects to the framework. Full article

Wood is the quintessential material for musical instruments due to its superior acoustic properties. However, its inherent susceptibility to environmental degradation—including moisture-induced dimensional changes, photodegradation, and biological attack—presents a fundamental challenge that treatment strategies must address. This critical review systematically examines recent advances in wood modification and surface protection technologies for musical instruments, encompassing chemical and thermal modification, protective coatings, physical densification, and biological treatments. Drawing on studies published over the past two decades, this review synthesizes current knowledge on how these interventions affect wood’s acoustic performance, dimensional stability, mechanical integrity, and long-term durability. A central finding is that treatment outcomes are highly species-specific and involve complex performance trade-offs: acoustic optimization often comes at the expense of mechanical strength or dimensional stability, and the optimal solution varies depending on the functional requirements of specific instrument components (e.g., soundboards versus fingerboards). Emerging bio-based and nanocomposite coatings show promise for enhancing environmental resistance, but their acoustic implications remain largely unexplored. Furthermore, most research remains at the laboratory scale, with limited validation on full instruments and a notable absence of long-term performance data under natural aging conditions. To advance the field from empirical trial-and-error toward predictive, knowledge-based design, this review identifies three priority areas for future research: (1) establishing cross-scale “treatment-structure-performance” correlation models that bridge molecular-level modifications to instrument-level acoustic outcomes; (2) developing intelligently engineered surface systems capable of multi-objective synergistic optimization; and (3) creating comprehensive assessment standards that encompass acoustics, durability, and sustainability. By systematically synthesizing current knowledge and identifying critical gaps, this review provides a foundation for more targeted, interdisciplinary research in instrument wood protection. Full article

A synergistic and magnetically recoverable NiFe₂O₄–MWCNT–CA nanocomposite was developed for efficient UV-driven photodegradation of hazardous organic pollutants. Biogenic NiFe₂O₄ nanoparticles synthesized using Costus speciosus extract exhibited a crystallite size of 32.5 nm, which increased to 83.6 nm upon incorporation into the MWCNT–cellulose acetate matrix. XRD confirmed the preservation of the cubic spinel structure, while VSM analysis showed maintained ferrimagnetic behavior with a saturation magnetization of 9.64 emu/g, enabling rapid magnetic separation. Although BET analysis revealed a reduction in surface area from 112.46 to 30.99 m²/g due to hybridization, the conductive MWCNT network significantly enhanced charge separation and interfacial electron transport. The composite displayed a widened optical bandgap of 5.3 eV, necessitating UV excitation for photocatalytic activity. Under UV irradiation, it achieved rapid degradation of methylene blue (97%) and Congo red (91%) at 20 mg/L, with corresponding rate constants of 0.119 and 0.076 min⁻¹. Scavenger experiments confirmed hydroxyl radicals (•OH) as the dominant reactive species, followed by photogenerated holes (h⁺). These results demonstrate a robust and synergistically engineered photocatalyst with high efficiency in removing organic pollutants under UV illumination. Full article

Growing concerns about environmental pollution and the sustainability of conventional nanomaterial synthesis have accelerated interest in plant-based routes for nanoparticle production. This review provides an in-depth analysis of more than 290 peer-reviewed research and review articles published between 2010 and 2025, extracted from the Web of Science and Scopus databases, on the green synthesis of metallic and metal oxide nanoparticles using plant extracts, with particular emphasis on their characterization and application in water treatment. Plant-derived phytochemicals serve as natural reducing and stabilizing agents, enabling nanoparticle formation without hazardous reagents. Key physicochemical characterization techniques, including UV–Visible spectroscopy, X-ray diffraction, Fourier Transform Infrared spectroscopy, scanning and transmission electron microscopy, and energy-dispersive X-ray analysis, are evaluated for their roles in confirming nanoparticle structure, morphology, surface chemistry, and optical behavior. The review focuses on water purification applications, highlighting adsorption and photocatalytic degradation as the most extensively investigated removal pathways. Particular attention is given to widely studied material classes such as silver, zinc oxide, titanium dioxide, and iron-based nanoparticles, which demonstrate effective removal of heavy metals, synthetic dyes, pesticides, and pharmaceutical residues. Current limitations related to synthesis reproducibility, mechanistic understanding, stability, and scalability are critically discussed. The review concludes by identifying priority research directions, including standardized synthesis protocols, deeper chemical analysis of plant extracts, and the integration of green nanoparticles into immobilized and membrane-based systems to advance their practical implementation in sustainable water treatment technologies. Full article

This study investigates pure and Ag-doped SrMoO₄ powders (Sr_1−xAg_xMoO₄, x = 0, 0.01, 0.07), focusing on structural, optical, and functional properties. We evaluate its photocatalytic performance, capacitance response in lactate solution and water, and antimicrobial activity in textiles. The diffraction patterns could be indexed to the pure tetragonal phase SrMoO₄. The doping of SrMoO₄ with Ag⁺ ions affects the morphology and particle size of the samples designed by co-precipitation. SrMoO₄ pure and Ag⁺-doped samples exhibited promising results in detecting water and lactate solutions, as well as photocatalysis. Pure SrMoO₄ was more efficient in the photodegradation of methylene blue (MB) than the sample doped with Ag⁺. Among the bactericidal test results, sample SMO:0.01-P4, without light, in S. aureus, and SMO:0.07-P3, with light in E. coli, showed a slight distance from the inhibition halo. These results suggest that the treated textile may possess a characteristic bactericidal capacity that deserves further exploration. This comprehensive analysis offers insights into the structure–function relationship of SrMoO₄:Ag and advances the development of multifunctional materials. Full article

In the current investigation, the solar photocatalytic degradation of two cationic model dyes (methyl green (MG) and crystal violet (CV)) was studied using α-Fe₂O₃/ZnFe₂O₄ nanocomposite. The fine powder of nanoparticles was obtained by co-precipitation method at pH = 10 and characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and UV-vis spectroscopy. The surface properties were further examined through temperature-programmed desorption (TPD) and point of zero charge (PZC) measurements to assess the acid–base characteristics and surface charge behavior of the material. Adsorption and photocatalytic performance were systematically evaluated in both single and binary systems. Dark adsorption experiments showed a better affinity of the α-Fe₂O₃/ZnFe₂O₄ heterosystem towards MG dye in both cases. Under natural sunlight irradiation in the individual system, the photocatalytic activity of the nanoparticles was significantly higher for MG (81.67% removal) compared to CV (41.70%). Kinetics analysis revealed that the photodegradation of both dyes followed a pseudo-first-order model. In binary systems, competitive adsorption effects strongly influenced the degradation behavior, with MG showing preferential adsorption and higher degradation rates. Moreover, the MG discoloration kinetics followed a second-order model, while CV kinetics transitioned from second- to zero-order with increased initial concentration. Full article

Titanium dioxide (TiO₂) nanotube arrays (NTAs) were constructed on Ti foil to immobilize Cu₂ZnSnS₄-TiO₂ (CZTS-T/NTAs) via the sol–gel dip-coating technique. The films were characterized by X-ray diffraction (XRD) patterns, field-emission scanning electron microscope–energy dispersive spectroscopy (FESEM-EDX), ultraviolet–visible diffuse reflectance spectra (UV–Vis/DRS), and electrochemical impedance spectroscopy (EIS) techniques. The photocatalytic property of CZTS-T/NTAs was evaluated by the photodegradation of Basic Blue 41 under visible light irradiation. We show that CZTS-T/NTAs have an energy band gap of 2.23 eV, which leads to excellent potential trapping or facilitates the transition of charge carriers under visible light. The parameters R₀ and C₀ of the experimental EIS data, by fitting the proposed electrical circuit, were also discussed. Decreasing R₀ led to an increase in cell capacitance, which resulted in increased carrier generation at the interface between the catalyst and solution and thus an increased photodegradation yield. The response surface methodology (RSM) and central composite rotatable design (CCRD) were used to optimize the effects of the experimental parameters in the degradation process by four key variables (pH, dye concentration, irradiation time, and hydrogen peroxide (H₂O₂) concentration). As a result, the optimized conditions attained a considerable degradation of 95.25%. We also proposed the possible photodegradation mechanism of the photocatalyst. Notably, the proposed catalyst after six consecutive reuse runs retained activity. Full article

PrFeTiO₃ perovskite composite was synthesized, and its structural, morphological, chemical, and optical properties were comprehensively characterized. X-ray diffraction (XRD) and a selected area electron diffraction (SAED) confirm the formation of an orthorhombic distorted perovskite phase with no secondary impurities. Transmission electron microscope (TEM) observations show aggregated nanocrystalline domains, while EDS mapping reveals homogeneous cation distribution (Pr, Fe, Ti, O), confirming successful incorporation of Fe and Ti into the perovskite lattice. X-ray photoelectron spectroscopy (XPS) analysis identifies Pr³⁺, Fe³⁺, and Ti⁴⁺ as the dominant oxidation states, supporting charge-compensated B-site substitution. Optical analysis reveals a bandgap of ~2.0 eV, significantly narrower than pristine titanates, indicating enhanced visible-light absorption. This multi-modal characterization verifies the successful formation of PrFeTiO₃ and highlights its potential as a visible-light-active photocatalyst. Although PrTiO₃ showed little reactivity to visible light, PrFeTiO₃ showed excellent efficiency in visible light photocatalytic reactions. PrFeTiO₃ showed more than 20 times better performance than PrTiO₃ in the photodegradation of methylene blue in the liquid phase and formaldehyde in the gas phase. Furthermore, PrFeTiO₃ showed more than 95% superior bactericidal activity against the pathogenic bacterium Staphylococcus aureus than PrTiO₃. Its high photocatalytic efficiency can be attributed to its strong photosensitivity to visible light and small band gap energy. Full article

Background: In this study, we aimed to compare metabolomic profiles, biodistribution, and detoxification patterns of the novel SN-38 derivative NMe with irinotecan (IR), and to identify NMe-specific metabolites to evaluate its preclinical pharmacokinetic advantages. Methods: In vivo ADME studies were conducted for NMe, a 9-aminomethyl SN-38 derivative, and IR following a single intraperitoneal dose of 40 mg/kg in mice. Additionally, ADMET properties were predicted using ADMETlab and SwissADME tools for comparison. Levels of NMe and irinotecan absorbed into plasma, distributed to tissues, and metabolized were monitored in liver, lung, spleen, kidney, and stool samples at 15, 30, and 60 min post-administration. Tissue extracts were analysed using high-performance liquid chromatography (HPLC), liquid chromatography–electrospray ionization quadrupole time-of-flight-tandem mass spectrometry (LC-ESI-QTOF-MS), and nuclear magnetic resonance (NMR) techniques after lyophilization and reconstitution. We compared the metabolomic profiles of irinotecan and NMe. Results: We identified and confirmed NMe-specific metabolites, including 9-CH₂-S-cysteine conjugate, 9-CH₂OH, and NMe-formyl. Notably, novel irinotecan metabolites (IR-OH and IR-ΔE) were detected in small amounts in kidney samples. In some cases, two literature-known photodegradation products of irinotecan were present. NMe was found to quickly metabolize with different distribution to tissues, significantly greater to kidney and liver. Two SN-38 glucuronides, SN-38G(α) and SN-38G(β), were detected corresponding to α- and β-anomers. Where it was possible, NMe, IR and SN-38 were quantified using external calibration curves. In IR group, controlled and prolonged release of SN-38 was confirmed in all samples, yet SN-38G was observed in minority only in plasma, kidney, or lungs. In NMe groups, great relative amounts of SN-38 and SN-38G were detected. Greater content of SN-38G in NMe group than in irinotecan is expected to contribute to modulation and alleviation of some side effects in irinotecan-involved therapies, such as gastrointestinal toxicities (GIT). Conclusions: NMe shows a distinct metabolic profile characterized by rapid biotransformation, higher systemic glucuronidation of SN-38, and formation of unique metabolites, suggesting a potentially wider therapeutic window and reduced toxicity compared with IR. Full article

Water purification and treatment methods are becoming increasingly complex due to the use of new additives, solvents, pesticides, dyes, and other emerging pollutants in industry, agriculture, and households. Consequently, the search for new water treatment techniques and materials that can help reduce this environmental impact has become a major focus in the field of green chemistry. In this work, the photocatalytic degradation capacity of composites containing TiO₂ nanoparticles (TNPs) for the removal of organic pollutants in water was studied. The TNPs were immobilized in bio-based hydrogel microparticles, which were prepared using microfluidic techniques. The composition of the dispersed phase was optimized with a lab-on-a-chip device, resulting in composite microparticles with a narrow size distribution. UV–visible spectroscopy results indicated that increasing the concentration of TNPs in the hydrogel microparticles enhanced the photodegradation performance of the new composite. Remarkably, it was able to efficiently degrade nearly 90% of reference dyes after four adsorption–desorption cycles. Full article

Emerging pharmaceutical pollutants such as acetaminophen (ACE) pose health and environmental risks. Solar photocatalysis provides a sustainable and efficient treatment option. In this study, UiO-66-NH₂ metal–organic framework was immobilized on cotton fabrics to enable their application in both batch and continuous flow systems. Cotton, a biodegradable and low-cost support, was first functionalized by two strategies: hydroxylation (-OH) and carboxylation (-COOH), to promote MOF anchoring. Cotton fabric functionalization and MOF growth were confirmed by ATR and X-ray diffraction, while SEM and EDX analyses revealed that carboxylated fibers achieved higher MOF loading. Photocatalytic experiments under simulated solar irradiation demonstrated significantly higher degradation of acetaminophen when the carboxylated cotton fabric-based catalyst (F-COOH-UiO-66-NH₂) was used. Mott–Schottky analysis and band alignment revealed that, under the applied reaction conditions, hydroxyl radical generation was not favored due to the position of the valence band. Studies with scavengers identified the superoxide radical as the dominant oxidative agent responsible for the photodegradation process. In particular, the F-COOH-UiO-66-NH₂ system demonstrated its suitability for application in continuous flow systems, achieving acetaminophen conversion of up to 50% under simulated solar irradiation. This confirms its potential for scalable application in practical water treatment technologies. These results reinforce the feasibility of immobilizing MOF-based photocatalysts on functionalized textile waste, offering a dual-purpose solution that combines the removal of pharmaceutical pollutants with the valorization of waste materials. The synergistic integration of high photocatalytic efficiency, sunlight harvesting and recyclability of the materials underlines the eco-friendly and cost-effective nature of the proposed strategy. Full article

The environmental degradation of plastics results not only in their mechanical fragmentation into microplastics (MPs), but also in polymer main-chain scission processes, causing continuous leaching and/or volatilization of low-molecular-weight species, often characterized by a hazardous profile. In this study, we investigated the hydrophilic photooxidation products (HyPOPs) generated upon UV irradiation of polystyrene (PS) and their transformation catalyzed by the enzyme laccase from the fungus Trametes versicolor. Through a series of enzymatic tests, the enzyme was found to promote coupling and conjugation reactions of HyPOPs into poorly soluble compounds mimicking natural humic acids. The enzymatic activity of laccase was studied under different experimental conditions to simulate those found in environmental matrices. Due to their oligomeric nature, these humic acid-like products of metabolic transformation by the fungal laccase are here nicknamed “mycoplastics” (i.e., polymers from fungi). This enzymatic biodegradation and biotransformation of xenobiotic HyPOPs highlights the role of specific enzymes as biological tools for environmental self-repair of polluted ecosystems. Moreover, it opens new perspectives for remediation strategies targeting elusive micro- and nanoplastics and their continuously generated hazardous molecular degradation by-products. Humic acid-like products resulting from laccase conversion of HyPOPs could contribute to the rehabilitation of contaminated sites by promoting the removal of toxic contaminants from soil and water. Full article

Plastics are highly persistent materials, and their environmental degradation can potentially exacerbate, rather than alleviate, pollution. The degradation of plastic materials releases toxic monomers and additives, such as bisphenol A (BPA), styrene, and dioxins, which are more reactive, harmful, and persistent than intact plastics. With half-lives ranging from weeks to decades, they bioaccumulate in food chains, disrupt ecosystems, and contribute to endocrine disruption and mutagenicity. Natural degradation pathways, like microbial metabolism and photodegradation, are slow and incomplete, often leaving toxic intermediates such as microplastics. Artificial strategies, including bioremediation and advanced oxidation processes (AOPs), show potential to address the problems of plastic pollution but face additional challenges like secondary pollution and scalability. Sustainable alternatives, including bioplastics and renewable non-plastic substitutes, present promising solutions. However, their widespread adoption is hindered by challenges such as high production costs and the need for specific conditions to facilitate degradation, necessitating further research and development. A combined approach of reducing plastic production, advancing recycling, and implementing effective remediation strategies is critical to mitigating plastic pollution’s long-term impacts on ecosystems, biodiversity, and human health. This review provides a critical analysis of the current understanding of plastic degradation processes and the toxic byproducts they generate. It highlights the paradox wherein increased degradability may exacerbate environmental hazards. Additionally, the review assesses innovative, eco-friendly alternatives designed to mitigate plastic pollution. Full article

Cannabinoids are of considerable current interest for use in pharmaceutical and non-medical consumer products. While there have been significant efforts to understand their chemical stability under ambient conditions, only sparse attention has been paid to characterising their photostability. Here, we present UVA (365 nm) and UVB (280 nm) photolysis measurements of eight representative cannabinoids, including natural compounds (THC, CBD, THCA, CBDA), metabolites (THC-COOH, THC-OH), and synthetic analogues (JWH-018, MDMB-FUBINACA). Measurements were performed using a novel online-electrospray mass spectrometry (MS) approach, where online photolysis of cannabinoid solutions was conducted with laser light-emitting diodes. MS detection was used to monitor precursor compound decay and photoproduct formation. Complementary results obtained via UV–Vis spectroscopy of photolysed cannabinoid solutions are also presented. For THC, CBD, THC-COOH, THC-OH, THCA and CBDA, significant photodegradation was observed with 280 nm photolysis, both through the appearance of photoproducts detected by MS and via time-dependent changes in the solution UV–Vis absorption profiles. In contrast, the synthetic cannabinoids (JWH-018 and MDMB-FUBINACA) showed negligible degradation with UVB photolysis, consistent with their relatively low absorbance propensity through the mid-UV region. No significant photodegradation was observed for UVA (365 nm) photolysis of any of the cannabinoids. The results presented here constitute the first directly comparable set of photolysis measurements for key phytocannabinoids. Full article

Desert oases and river systems are complex and dynamic ecosystems featuring unique hydrological patterns. The system significantly influences the production, degradation, and transformation of dissolved organic matter (DOM), thereby further regulating DOM in the desert oasis. However, the molecular composition and significance of DOM in rivers within desert oases are rarely studied. In this paper, the optical properties and spatial variation in molecular characteristics of surface water DOM in the Aksu River were investigated using three-dimensional fluorescence spectroscopy (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results indicated that the rivers possess distinct molecular compositional characteristics of DOM, with high spatial heterogeneity (variations in optical parameters and molecular compounds). Diversity in DOM is revealed at the molecular level primarily through S- and N-containing functional groups. Unlike large rivers (e.g., the Yangtze) dominated by terrestrial inputs or algal blooms, our study reveals that the DOM in the Aksu River (a desert-oasis river) is characterized by highly unsaturated and phenolic compounds and is primarily driven by intense photodegradation and evaporation rather than by microbial or terrestrial allochthonous inputs. This highlights a distinct photochemical signature unique to arid river systems. The findings will deepen the understanding of the DOM in desert-oasis river systems. Based on this research, seasonal variation in DOM in the Aksu River under different hydrological conditions can be further studied, thereby enriching the understanding of the carbon cycle in desert-oasis river systems. Full article