Search Results (1,621)

The catalytic removal of toluene, a representative aromatic volatile organic compound (VOC), requires efficient and stable catalysts. This study systematically investigated the effect of B-site doping with transition metals (Fe, Cu, and Ni) on the catalytic performance of LaMnO₃ perovskite for toluene oxidation. The LaMn_0.5X_0.5O₃ catalysts were synthesized via a sol–gel method and evaluated. The LaMn_0.5Ni_0.5O₃ catalysts exhibited the optimal catalytic performance, achieving toluene conversion temperatures of 243 °C at 50% conversion (T₅₀) and 296 °C at 90% conversion (T₉₀). Comprehensive characterization revealed that Ni doping effectively refined the catalyst’s microstructure (grain size decreased to 19.21 nm), increased the concentration of surface-active oxygen species (142.7%), elevated the Mn⁴⁺/Mn³⁺ ratio to 0.65, and enhanced lattice oxygen mobility. These modifications collectively contributed to its outstanding catalytic activity. The findings demonstrate that targeted B-site doping, particularly with Ni, is a promising strategy for engineering efficient perovskite catalysts for VOC abatement. Full article

Transition metal (TM)-doped zinc oxide (ZnO) and zirconium dioxide (ZrO₂) nanocrystals exhibit complex correlations between crystal structure, defect chemistry, vibrational properties, and magnetic behavior that are strongly governed by synthesis route and dopant incorporation mechanisms. This review critically summarizes recent progress on Fe-, Mn-, and Co-doped ZnO and ZrO₂ nanocrystals synthesized by wet chemical, hydrothermal, and microwave-assisted hydrothermal methods, with emphasis on synthesis-driven phase evolution and apparent solubility limits. ZnO and ZrO₂ are treated as complementary host lattices: ZnO is a semiconducting, piezoelectric oxide with narrow solubility limits for most 3d dopants, while ZrO₂ is a dielectric, polymorphic oxide in which transition metal doping may stabilize tetragonal or cubic phases. Structural and microstructural studies using X-ray diffraction, electron microscopy, Raman spectroscopy, and Mössbauer spectroscopy demonstrate that at low dopant concentrations, TM ions may be partially incorporated into the host lattice, giving rise to diluted or defect-mediated magnetic behavior. When solubility limits are exceeded, nanoscopic secondary oxide phases emerge, leading to superparamagnetic, ferrimagnetic, or spin-glass-like responses. Magnetic measurements, including DC magnetization and AC susceptibility, reveal a continuous evolution from paramagnetism in lightly doped samples to dynamic magnetic states characteristic of nanoscale magnetic entities. Vibrational spectroscopy highlights phonon confinement, surface optical phonons, and disorder-activated modes that sensitively reflect nanocrystal size, lattice strain, and defect populations, and often correlate with magnetic dynamics. Rather than classifying these materials as diluted magnetic semiconductors, this review adopts a synthesis-driven and correlation-based framework that links dopant incorporation, local structural disorder, vibrational fingerprints, and magnetic response. By emphasizing multi-technique characterization strategies required to distinguish intrinsic from extrinsic magnetic contributions, this review provides practical guidelines for interpreting magnetism in TM-doped oxide nanocrystals and outlines implications for applications in photocatalysis, sensing, biomedicine, and electromagnetic interference (EMI) shielding. Full article

This study investigates the valorisation of mixed municipal waste glass (MMWG; EWC 20 01 02) as a sustainable supplementary material in cement mortars. In contrast to most existing studies, which focus almost exclusively on homogeneous container glass, this work addresses a heterogeneous waste stream derived from municipal selective collection, containing flat glass, mirrors, ceramics, porcelain, and metallic residues. Such mixed household glass has not previously been systematically evaluated in cement mortars, thereby addressing a clear research gap. The MMWG was washed, dried, and ground in a Los Angeles drum with corundum abrasives to obtain a fine glass powder (FGP < 63 µm) with a median particle size of approximately 20 µm and a Blaine fineness of 360 m²/kg. Microstructural and chemical characterisation of the milled glass confirmed its highly amorphous nature and angular particle morphology resulting from grinding. In addition, coarse glass granules (0–4 mm) were used as partial replacements for natural sand in mortar mixtures. The incorporation of FGP led to a 4–12% reduction in flowability, attributable to the angular shape and increased specific surface area of the ground-glass particles. At 28 days, mortars containing 5–10% FGP exhibited mechanical properties comparable to the reference mix, while at 56 days their compressive strength increased by up to 8%, indicating delayed pozzolanic activity typical of finely milled, amorphous glass. Mortars containing coarse glass primarily reflected a filler and aggregate-replacement effect. Leaching tests conducted in accordance with PN-EN 12457-4 demonstrated that all mortars, both reference and MMWG-modified, complied with the non-hazardous waste limits defined in Council Decision 2003/33/EC. Minor exceedances of Ba and Cr relative to inert-waste thresholds were observed; however, these values remained within the permissible range for non-hazardous classification and were attributed to ceramic and metallic contaminants inherently present in the mixed glass fraction. Overall, this study demonstrates that mixed municipal waste glass—a widely available yet rarely valorised heterogeneous waste stream—can be effectively utilised as a finely ground supplementary material and as a partial aggregate replacement in cement mortars, provided that particle fineness is adequately controlled and durability-related effects are monitored. The findings extend the applicability of glass waste beyond container cullet and support the development of circular-economy solutions in construction materials. Full article

Ruthenium-based catalysts supported on TiO₂, SnO₂, and WO₃ were synthesized via a microwave-assisted rapid reduction method and evaluated for the hydrogen evolution reaction (HER) in acidic media. The Ru species existed as highly dispersed nanoclusters, as confirmed by XRD and TEM, and the catalytic activity was strongly dependent on the oxide support. Ru/TiO₂ exhibited the best HER performance, achieving an overpotential of 187 mV at 10 mA·cm⁻² and a Tafel slope of 97.56 mV·dec⁻¹. While particle size differences (1.8–3.7 nm) did not account for the activity trend, XPS revealed distinct metal–support interactions that modulated the electronic state of Ru. Ru/TiO₂ showed an intermediate electron depletion that optimizes the Ru-H binding strength, explaining its superior kinetics. Regulation of Ru loading further identified Ru/15TiO₂ as the optimal catalyst, exhibiting low charge transfer resistance and excellent stability over 17 h. This study highlights the critical role of support-induced electronic modulation and loading engineering in designing efficient Ru-based electrocatalysts for acidic HER. Full article

Although carbon filters (CF) can exhibit limited adsorption/selectivity for certain emerging pollutants and operating conditions, incorporating carbon–metal-oxide composites provides a platform to study how surface chemistry, charge distribution and oxide dispersion influence adsorption behavior. This study investigates the incorporation of metal oxides (Fe₃O₄, TiO₂ and CaO) into a commercial carbon filter via mechanical milling, focusing on fundamental changes in surface properties and methylene blue (MB) adsorption mechanisms. The synthesized oxides were characterized by X-ray diffraction and scanning electron microscopy, confirming crystalline structures with crystalline sizes between 11 and 23 nm. Composite filters with varying oxide contents (10–30 wt%) were evaluated for point of zero charge (PZC), surface charge distribution and methylene blue (MB) adsorption. The kinetic experiments were adjusted to pseudo-second order (PSO). Although the maximum adsorption capacity (2.75 mg·g⁻¹ for CaO-modified filters) is lower than commercially activated carbons, this work clarifies how oxide type and dispersion control adsorption performance and interaction mechanisms. Langmuir and Freundlich models revealed monolayer adsorption with favorable dye-surface interactions. These models provide key insights into the role of oxide type and pH in the dye removal process. Full article

Metal-organic frameworks (MOFs) offer high porosity for water remediation but face challenges in handling as powders. We address these limitations by physically immobilizing Fe–BTC MOF within calcium-crosslinked low-methoxyl pectin matrices (PE–Ca–MOF). Solvent-cast films and freeze-dried foams were fabricated using water-based and polyvinylpyrrolidone (PVP)-assisted Fe–BTC dispersions, preserving MOF and pectin structures confirmed by FT–IR. PVP improved Fe–BTC dispersion and reduced particle size, enhancing distribution and plasticizing the matrix proved by DSC. Incorporation of water-dispersed Fe–BTC increased the equilibrium adsorption capacity but reduced the initial adsorption rate, while the PVP-assisted foam further enhanced uptake in comparative batch tests through its more open porous structure. At pH 7, PE–Ca–5%MOF films showed high adsorption capacities and removal efficiencies for paraquat (35.5 mg/g, 70.6%) and tetracycline (14.5 mg/g, 46.8%), while maintaining Zn²⁺ uptake compared to calcium-pectin films without MOF. Adsorption followed pseudo-first-order kinetics and Langmuir isotherms. Green regeneration with acetic acid enabled >80% capacity retention over five adsorption–desorption cycles. Foam architectures increased porosity and active-site accessibility (SEM), improving performance even at lower MOF loadings. Overall, controlling MOF dispersion and composite morphology enables efficient, reusable, and environmentally friendly bio-based adsorbents for water purification. Full article

Background: Minimally invasive approaches for managing complications of acute necrotizing pancreatitis have advanced significantly in recent decades. When extensive walled-off pancreatic or peripancreatic necrosis is present, a single transluminal access may be insufficient. This study aimed to prospectively evaluate the effectiveness and safety of a novel percutaneous endoscopic necrosectomy technique used as an adjunct to transmural drainage in patients with symptomatic walled-off necrosis. Methods: A total of 513 consecutive patients with symptomatic walled-off pancreatic or peripancreatic necrosis treated between 2018 and 2025 at a single tertiary center in Poland were included. All patients underwent minimally invasive endoscopic management. Among them, a subgroup required additional percutaneous drainage. The innovative technique involved creating retroperitoneal percutaneous access to the necrotic cavity, enlarging the tract, and placing a self-expanding metal stent to allow passage of the endoscope for percutaneous endoscopic necrosectomy. Results: Additional percutaneous drainage was necessary in 39/513 patients (7.6%). Of these, 9/39 (23.1%) patients (2 women, 7 men; mean age 46.7 years) underwent percuaneous endoscopic necrosectomy. The mean size of the necrotic collection was 25.96 cm. Active percutaneous drainage during ongoing transmural endotherapy lasted a median of 15 days. Patients underwent an average of 3.12 necrosectomy sessions. Treatment-related complications occurred in 2/9 patients (22.22%). Clinical and long-term success were each achieved in 8/9 patients (88.89%). Conclusions: Percutaneous endoscopic necrosectomy is a promising minimally invasive therapeutic option for extensive walled-off pancreatic and peripancreatic necrosis, particularly when necrosis extends into the pelvic region. However, clinical evidence remains limited and further studies are needed. Full article

The use of e-fuels, such as methanol (MeOH), is considered an alternative for the reduction of carbon emissions. MeOH can be produced from captured CO₂ and green H₂, with the exothermic (equilibrium-limited) reaction favoured at low temperatures and high pressures. However, CO₂ is a very stable molecule and requires high temperature (>200 °C) to overcome the slow activation kinetics. In this study, MeOH was synthesized from CO₂ and H₂ in a packed-bed membrane reactor (PBMR) using a commercial Cu/ZnO/Al₂O₃ catalyst and a tubular-supported, water-selective composite alumina–carbon molecular sieve membrane (Al-CMSM) immersed in the catalytic bed. A mixture of H₂/CO₂ (3/1) was fed into both sides of the membrane to increase the driving force of the gases produced by the reaction. The effect of the temperature of reaction (200, 220, and 240 °C), pressure difference (0 and 3 bar), and the sweep gas/reacting gas ratio (SW = 1, 3, 5) in the CO₂ conversion and products yield was studied. For comparison, the reactions were also carried out in a packed-bed reactor (PBR) configuration where the tubular membrane was replaced by a metallic tube of the same size. CO₂ conversion and MeOH yield are much higher in PBMR than in PBR configuration, showing the benefit of using the water-selective membrane. In PBMR, MeOH yield increases with SW and slightly decreases with the temperature, overcoming the limitation imposed by the thermodynamics. Full article

The selective hydrogenation of phenol to cyclohexanone is a pivotal reaction for producing nylon precursors. Conventional Pd/C catalysts, however, suffer from weak metal–support interactions, leading to size heterogeneity and agglomeration of Pd nanoparticles, which degrades their activity and stability. Herein, we report a facile argon plasma treatment to engineer rich defects on an activated carbon (AC) support, resulting in a highly dispersed and stable catalyst (denoted as PL-Pd@AC_Ar). Characterization results indicate that the abundant carbon defects in PL-Pd@AC_Ar enhance the anchoring of Pd precursors, ensure the uniform dispersion of Pd nanoparticles, and effectively modulate their electronic structure. Consequently, the plasma-enabled PL-Pd@AC_Ar catalyst achieves 99.9% phenol conversion with 97% selectivity to cyclohexanone at a mild temperature of 70 °C and maintains exceptional stability over six consecutive cycles. This work provides a robust and efficient strategy for the surface engineering of carbon supports to design high-performance hydrogenation catalysts. Full article

Microparticles (MPs) are delivery systems for bioactive compounds with particle sizes in the micrometer range (1–1000 μm). This study reports a green protocol for the biosynthesis of ZnO-, MgO-, and CaO-MPs using the probiotic strains Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Leuconostoc mesenteroides. Ultraviolet–visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS) were used for the preliminary characterization of the metal oxide MPs. Antimicrobial activity was evaluated against pathogenic and phytopathogenic microorganisms, including Salmonella typhimurium, Staphylococcus aureus, Escherichia coli, and Ralstonia solanacearum. UV-Vis analysis revealed previously reported blue shifts in the ZnO- and CaO-MPs. DLS measurements showed particle sizes larger than 1000 nm in 95% of the cases, while smaller sizes were observed by SEM. The stability of the MPs, based on their zeta potential values, ranged from relatively to moderately stable. This study demonstrates that the six probiotic lactic acid bacteria strains are capable of synthesizing ZnO-MPs, CaO-MPs, and MgO-MPs. All MPs exhibited antimicrobial activity against pathogens and phytopathogens at different concentrations. Although similar antimicrobial effects have been reported for metal oxide nanoparticles produced by probiotic bacteria, considering the potential environmental and human health impacts of nanoparticles, the use of safer materials obtained through green synthesis—such as metal oxide MPs—may represent a more suitable alternative. Full article

Supercapacitors based on mixed metal oxides are being developed as potential devices for large-scale energy storage applications with physical flexibility, thanks to their low cost and good electrochemical performance. This work demonstrates a novel approach to enhancing the electrochemical performance of bismuth–cerium oxide BiCeO₃ (BC) through thiourea doping. The incorporation of sulfur, confirmed by EDS, induced significant structural modifications, including a reduction in crystallite size from 42.5 nm to 34.8 nm and the emergence of new diffraction planes (002) and (222) in XRD patterns. These changes, indicative of successful lattice doping, yielded a more nanostructured morphology with increased active surface area and a 20% reduction in the optical band gap. Electrochemically, the thiourea-doped BiCeO₃ (BCT) electrode delivered a marked improvement, exhibiting a specific capacitance of 150 F·g⁻¹ at 25 mV·s⁻¹, a 17.2% increase over the pure BiCeO₃ (128 F·g⁻¹). Furthermore, BCT demonstrated superior rate capability and a 43% reduction in overall impedance, underscoring enhanced charge transfer kinetics and ionic conductivity. The synergy between sulfur-induced structural defects, increased electroactive surface area, and improved electronic structure establishes thiourea doping as an effective strategy for developing high-performance BiCeO₃-based supercapacitors. Full article

The field of nanotechnology has witnessed a paradigm shift towards eco-friendly and sustainable synthesis methods for nanoparticles due to increasing concerns over environmental toxicity and resource sustainability. Among various metal oxide nanoparticles, zirconium dioxide (ZrO₂) nanoparticles have garnered significant attention owing to their exceptional thermal stability, biocompatibility, mechanical strength, and catalytic properties. Doping ZrO₂ with transition metals such as copper (Cu) further enhances its physicochemical attributes, including antibacterial activity, redox behaviour, and electronic properties, rendering it suitable for a diverse range of biomedical and industrial applications. In the present study, we report the green synthesis of copper-doped ZrO₂ nanoparticles (Cu-ZrO₂-CO NPs) using an aqueous extract of Calendula officinalis (marigold) flowers as a natural reducing and stabilizing agent. The complete characterization was performed using UV–vis spectrophotometry, dynamic light scattering (DLS), zeta potential, FTIR, SEM, EDAX, and XRD, revealing its size to be around 20–40 nm and zeta potential as −20 mV, indicating nano size and stability. The biocompatibility of the as-synthesized nanoparticle was analyzed in vitro using fibroblast cell viability and haemolysis assay, and in vivo using brine shrimp assay. The nanoparticles were safe up to a dose of 50 μg/mL, showing more than 95% cell viability and less than 2% haemolysis, which is within an acceptable range. Finally, the anticancer activity was explored for A549 cells by MTT assay and live-dead assay, with an IC50 value of 38.63 μg/mL. The chorioallantoic membrane (CAM) model was used to assess the anti-angiogenesis potential of the Cu-ZrO₂-CO NPs. The results showed that the nanoparticles could kill the cancer cells via apoptosis, and one of the reasons for the anticancer effect was angiogenesis inhibition. Further research is needed using other cancer cell lines and animal tumour models. Full article

Microbial fermentation stands as the foundational technology in modern biorefineries, yet its industrial scalability is critically constrained by product inhibition, prohibitive downstream separation costs, and substrate inhibition. Metal–organic frameworks (MOFs) offer a tunable material platform to address these challenges through rational design of pore size, shape, and chemical functionality. This review systematically chronicles the evolution of MOF applications in biomass fermentation across four generations, demonstrating a synergistic mapping where the core fermentation challenges—product toxicity, substrate toxicity, and separation energy intensity—align with the inherent MOF advantages of high adsorption capacity, programmable selectivity, and tunable functionality. The applications progress from first-generation passive adsorbents for in situ product removal, to second-generation protective agents for mitigating inhibitors, and third-generation immobilization scaffolds enabling continuous processing. The fourth-generation systems transcend passive scaffolding to position MOFs as active metabolic partners in microbe-MOF hybrids, driving cofactor regeneration and tandem biocatalysis. By synthesizing diverse research streams, ranging from defect engineering to artificial symbiosis, including defect engineering strategies, this review establishes critical design principles for the rational integration of programmable materials in next-generation biorefineries. Full article

Ensuring good air quality in indoor environments of historical and artistic significance is essential not only for protecting valuable artworks but also for safeguarding human health. While many studies in this field tend to focus on the preservation of cultural heritage, fewer have addressed the impact on visitors and worshippers. Yet, places such as museums, galleries, churches, and other religious sites attract large numbers of people, making indoor air quality a key factor for their well-being. This study focused on evaluating air quality within the Santuario della Beata Vergine dei Miracoli in Saronno, Italy, a religious site that welcomes large numbers of visitors and worshippers each year. A detailed analysis of particulate matter was conducted, including chemical characterization by ICP-MS for metals, ion chromatography for water-soluble ions, and thermal–optical analysis for the carbonaceous fraction, as well as assessments of size distribution and radiometric properties. The results indicated overall good air quality conditions: concentrations of heavy metals were below levels of concern (<35 ng m⁻³), and gross alpha, beta, and ¹³⁷Cs activity concentrations remained below the minimum detectable thresholds. Hence, no significant health risks were identified. Full article

Gallium-based liquid metals have been extensively studied in the field of biomedical engineering, including applications in tumor and inflammatory disease therapy, as well as targeted drug delivery. Among these, leveraging the photothermal effect of gallium liquid metals enables effective treatment of heat-sensitive cells in tumor regions and enhances the diffusion capability of liquid metal microdroplets. However, research on the active treatment of ulcerative colitis (UC) using photothermal therapy with liquid metals remains unexplored. This study focuses on constructing an active composite colloidal motor based on gallium indium liquid metal alloy, using liquid metal microdroplets as the core. Through layer-by-layer assembly of polyelectrolytes, a liquid metal active droplet loaded with the drug mesalazine (5-aminosalicylic acid), named as LMAD-A was developed. Under asymmetric light fields generated by NIR-II light source irradiation, LMAD-A exhibits autonomous locomotion, achieving an effective diffusion coefficient more than 800 times greater than that of Brownian motion in liquid metal microdroplets of similar size. Furthermore, LMAD-A demonstrates phototactic behavior, moving toward the NIR light source autonomously. Through in vitro and in vivo experiments in mice, it was verified that LMAD-A can aggregate, deform, and fuse in the mouse colon under photothermal effects, leading to enhanced release of the loaded drug. In simulated treatments, LMAD-A significantly alleviated DSS-induced colitis in mice, confirming the targeted therapeutic capability of active liquid metal microdroplets as an active therapeutic agent in UC-affected regions. Full article