Metal Precursors Research Articles

Rapid photothermal reduction-derived Pt1.6Ni nanoalloys embedded in laser-induced graphene for hydrogen evolution reaction

Water electrolysis is one of the most intriguing technologies for hydrogen production because of its carbon-neutral nature, however the development of efficient electrocatalysts is required to improve the energy conversion efficiency of water splitting. In this study, we suggest a facile route for the fabrication of Pt1.6Ni nanoalloys on laser-induced graphene (Pt1.6Ni NAs/LIG) by the photothermal reduction using commercial CO2 laser which is irradiated on the surface of the LIG. The laser ablation process on the polyimide (PI) film resulted in porous and interconnected graphene sheets, while uniform nanoparticles with an average size of around 4.5 nm were decorated on their surface by the photothermal reduction effect. The overall process took only 60 s. Bonding structure investigation confirmed that PI film was successfully transformed into a graphene structure and the metal precursors were converted into bimetallic nanoalloy by using Raman spectroscopy and XPS, respectively. Electrochemical measurements for hydrogen evolution reaction discovered that the Pt1.6Ni NAs/LIG showed superior catalytic performance which required an overpotential of only 96 mV to achieve a current density of 10 mA cm−2. It exhibited superior catalytic activity compared to LIG (740 mV), Pt NPs/LIG (204 mV), and PtNi1.6 NAs/LIG (205 mV), as well as other previously reported catalysts at the same current density. Based on these results, the Pt1.6Ni NAs/LIG was employed for hydrogen gas collection and detection. The generated bubbles were collected separately from both electrodes, and their compositions with evolution rate were confirmed to be hydrogen using a commercial H2 sensor.

Processable CMP aerogel with Ag nanocatalysts for the treatment of combined pollutant containing p-NP&MO in continuous flow

It is challenging to produce soft polymer materials with high surface area and nanoscale morphology that can be used for continuous flow water treatment in a processable, versatile, and stable manner. Here, we manufactured a processable Ag@CMPA-bph and used it to treat pollutants in wastewater at continuous flow conditions. The aerogel was prepared by a simple reduction method of CMP matrix and Ag metal precursors. Thermogravimetric analysis and electron microscopy showed that the aerogel had excellent thermal stability and distribution of fine Ag nanoparticles. The synthesized aerogel inherits the controllable properties of the CMP matrix and can be tailored to a specific shape for installation into the water treatment unit. In continuous flow conditions, this aerogel shows excellent catalytic activity to efficiently treat the combined pollutant containing p-nitrophenol and methyl orange (p-NP&MO), which can reach a removal rate of more than 99 % at the flow rate of 0.6 L h-1. Furthermore, the Ag@CMPA-bph can also be used for continuous flow treatment of pollutants in river water sample and shows robust anti-pollution load capacity and catalytic activity.

Morphology controlled synthesis of MnCo2S4 nanoflower structures for different metal precursors used for energy storage applications

Supercapacitors have been considered efficient energy storage devices because of their promising electrochemical charge storage capabilities. Nevertheless, an efficient electrode material is needed to fulfill the demands of current supercapacitor technology. This study examines the influence of various metal precursors (acetate (A), nitrate (N), and chloride (C)) on the morphology-dependent supercapacitor performance of MnCo2S4 (MCS) fabricated on nickel foam using an in situ hydrothermal method to obtain an optimized electrode material. The flower-like porous morphology of MCS N provides a maximum number of electrochemically active sites to the electrode material, enhancing the attainable surface area of the electrolyte upon increasing the electrochemical performance. The electrode material MnCo2S4 derived from a nitrate precursor exhibits higher specific capacity compared to MCS A and MCS C, reaching 2367C g−1 at 1 A g−1 and demonstrating 90 % cycles stability over 5000 cyclings. Likewise, an asymmetric supercapacitor (ASC) is developed by coupling activated carbon (negative electrode) with MnCo2S4 (positive electrode), yielding notable performance, such as 217 F g−1 capacitance at 1 A g−1, along with high energy and power densities of 63.3 Wh/kg and 6000 W kg−1, correspondingly. These outcomes emphasize the morphology-dependent behavior of MnCo2S4 in advancing supercapacitor design.

Assessing the matrix effects on MALDI-MS in the positive and negative ion mode detection for protein-protected metal nanoclusters

Protein-protected metal nanoclusters (MNCs) represent a new class of highly photoluminescent nanomaterials that have wide applications. Suitable reaction conditions combining protein and metal precursors can produce a vast range of different NC sizes (i.e. different number of metal atoms). The average number of metal atoms per protein can be determined by mass spectrometry (MS). MS coupled with matrix-assisted laser desorption ionization (MALDI) presents a number of advantages such as detection with high sensitivity of nanoclusters with high molecular weights. Although many protein-protected MNCs have been characterized by MALDI-MS, a large dispersion in the number of metal atoms has been reported mainly due to sample preparation. In this work, we optimized the protocols for negative and positive ion detection mode as a general MALDI-MS sample preparation method for protein-protected MNCs (bovine serum albumin and lysozyme and with gold and silver). Negative and positive ion mode detection was compared, showing that negative ion mode detection in MALDI-MS can also be used with acidic matrices. Obvious matrix effects on ion signals and peak positions by MALDI-MS were observed. The average metal numbers of MNCs embedded in proteins are different depending on the MALDI matrix. The matrix effects give a warning for more serious consideration on MALDI-MS measurement and spectra analysis of MNCs.

Controlled Localized Metal-Organic Framework Synthesis on Anion Exchange Membranes.

Metal-organic framework (MOF) films can be used in various applications. In this work, we propose a method that can be used to synthesize MOF films localized on a single side of an anion exchange membrane, preventing the transport of the metal precursor via Donnan exclusion. This is advantageous compared to the related contra-diffusion method that results in the growth of a MOF film on both sides of the support, differing in quality on both sides. Our proposed method has the advantage that the synthesis conditions can potentially be tuned to create the optimal conditions for crystal growth on a single side. The localized growth of the MOF is governed by Donnan exclusion of the anion exchange membrane, preventing metal ions from passing to the other compartment, and this leads to a local control of the precursor stoichiometry. In this work, we show that our method can localize the growth of both Cu-BTC and ZIF-8 in water and in methanol, respectively, highlighting that this method can used for preparing a variety of MOF films with varying characteristics using soluble precursors at room temperature.

Continuous 3D printing of metal structures using ultrafast mask video projection initiated vat photopolymerization

Additive manufacturing (AM) has recently emerged as the go-to technology for producing high-quality metal components to address cutting-edge research and industrial challenges. However, existing metal AM technologies operate on a layer-by-layer basis, giving rise to undesirable "staircasing effects" that result in the anisotropic behavior. Additionally, conventional metal printing methods are constrained by printing times, expensive hardware, and limited resolution control. In response to these limitations, this work is dedicated to the development of a cost-effective, ultra-fast layerless metal AM process for crafting intricate 3D metal structures. Low viscous resin was developed to enable continuous printing of metal precursors via mask video projection-based vat photopolymerization, which enable tunable physical properties and superior surface quality. Based on experimental findings, high-density meso- and microscale metallic parts can be printed at speeds orders of magnitude faster than commercial metal AM technologies. Furthermore, printed metallic components display a uniform morphology and microstructure with consistent grain size distribution. A comparative analysis of the surface quality between layer-based and layer-less printed metal structures were conducted. This work has the potential to revolutionize not only the field of AM but also various industries reliant on high-quality metal components, such as aerospace, automotive, and medical devices.

Doping of photoactive TiO2 films by DC plasma electrolytic oxidation: Effect of transition metals

Several beneficial features maintain TiO2 in the top list of viable materials for photocatalytic purposes. However, its relatively large band-gap (3.0–3.2 eV) still hampers practical applications under sunlight. This work explores Direct Current (DC) Plasma Electrolytic Oxidation (PEO) of titanium as a fast, easily-scalable and single-step tool to synthesise doped TiO2 photoanodes with controlled morphology, crystalline structure and thickness. Zn-, Cu- and Fe-doped crystalline TiO2 films were obtained in H2SO4 aqueous solutions containing ZnSO4, CuSO4 and FeSO4 precursors, respectively. As-prepared TiO2 films showed a porous and homogeneous sponge-like surface morphology, typical of PEO-produced oxides, and a crystalline phase structure consisting of a mixture of anatase and rutile phases. The anatase content varied in the 54–100 % range and correspondingly the band-gap energy was in the 2.85–3.07 eV range. Doped oxides prepared with a low concentration of the metal precursors showed monochromatic incident-photon-to-current-efficiency (IPCE) values exceeding those obtained with pristine TiO2 by up to 24 %, best performing in the order Zn- > Cu- > Fe-doped TiO2. Photocurrent under polychromatic UV-Vis irradiation showed an analogous trend and the estimated efficiency of solar-light harvesting was in the 0.3–4 % range, with Zn- ≈ Cu- > Fe-doped TiO2. Although the superior performance of the PEO-prepared metal-doped TiO2 could not be fully confirmed by photoelectrocatalytic oxidation tests of organics, the present investigation showed the viability of DC PEO for the synthesis of metal-doped TiO2 photoanodes.

Experimental Investigation for the Preparation of Taro Leaf Nanoparticles by Sol-Gel Method and its Characterization

Abstract: In the present work, nano particles of Taro leaf were successfully synthesized chemically by modified Sol-gel method. Methanol is used as a solvent and buffers are added to take care for the homogeneity and PH value of the solution. Compared to micro particles, Nanoparticles have advanced characteristics and distinctly different properties. Taro leaf nanoparticles are one of the leaves nanoparticles which has varied and different properties when compared to other. Taro Leaf nanoparticles have considerable attention due to their attractive physical and chemical properties, Silver nitrate is taken as the metal precursor and sodium borohydride as a reducing agent. This preparation is simple, but the great care must be exercised to make stable particles. Here the Taro leaf nanoparticles are synthesized by sol gel process. Therefore the nanoparticles are characterized by the different techniques like SEM to find the size morphology and composition of leaf nanoparticles, XRD to know the lattice parameters. The peaks in the XRD pattern are in good agreement with the standard values.

Structural and Optical Properties of Fe Doped Tio<sub>2</sub> Nanoparticles: Investigation of Effects of Different Doping Concentration

Fe-doped TiO<sub>2</sub> nanoparticles (F-T NPs) were synthesized using the sol-gel method where different molar concentrations (0, 1, 2, 3, 5, 7, 9, and 10%) of Iron (iii) nitrate were added to a constant amount of the metal precursor TetraisopropylOrthotitanate (TTIP) solution, the solvent precursor ethanol and refluxing agent diethanolamine at the ratios of 1:6:1 respectively. The gel formed was annealed at 500°C in a muffle furnace for 2h. Fourier Transform Infrared (FTIR) showed Fe-O symmetrical stretching vibration for the 5% doping and above and Ti-O-Fe asymmetrical stretching vibration at wavenumber 668 cm<sup>-1</sup> and 1033cm<sup>-1</sup>, respectively. Fe-O stretching vibration confirms substitution doping. The crystallite size was calculated using the Debye Scherer equation; 2% F-T NPs had the largest crystallite size at 16.45 nm, and 7% F-T NPs had the least size at 10.95 nm, a decrease of 2.80 nm from the 0% F-T NPs. X-ray diffraction spectra showed a merging of peaks at planes 105 and 211. The peak at plane 204 is found to diminish, and the growth of another peak at 2θ (64.28°). Optical analysis was studied using UV-Vis, where the Tauc plot estimated the calculated band gap (E<sub>g</sub>). It was the least at 7% F-T NPs with a value of 4.41 eV, and 5% F-T NPs were found to have the highest value of 4.86 eV.% Transmittance is directly proportional to the optical band gap. Scanning Electron Microscope showed improved agglomeration and aggregation with a dense and smooth particle. Energy Dispersive Spectroscopy confirmed the presence of Fe, Ti, and O in the F-T NPs.

Batch production of centimeter-scale monolayer MoS2 with low nucleation by face-to-face metal precursor supply

Transition-metal dichalcogenides (TMDs) show great potential for next-generation semiconductor due to its atomic level thickness, tunable band gap and high carrier mobility. However, high-quality monolayer MoS2 (ML-MoS2) films require stringent growth conditions during preparation. Here, we report a face-to-face metal precursor supply approach during chemical vapor deposition (CVD) to batch production of uniform ML-MoS2 films. Mo foils provide a stable concentration of metal precursors leading to uniform film generation with low nucleation. Comprehensive characterization techniques, including spectroscopic, surface topography and atomic scale analysis confirm the centimeter-scale homogeneity and high crystallographic quality of the monolayer films. Back-gate field effect transistors (FET) fabricated by ML-MoS2 exhibit excellent electrical performance. This methodology provides a pathway for the growth of TMDs, which should promote their applications in high-performance electronics or other fields.

Morphological and Structural Characterization of (Pt, Au, and Ag) Nanoparticle/Zn-MOF-74 Composites.

Metallic nanoparticles (NPs) were decorated onto Zn-MOF-74 crystals by photoreducing different metal precursors (Pt, Au, and Ag) using ultraviolet (UV) light in an aqueous solution with different metal concentrations without using additional stabilizers. X-ray diffraction revealed the three-dimensional structural integrity and crystallinity conservation of Zn-MOF-74 crystals during the UV decoration process. Raman spectroscopy showed a minor rearrangement in the structure of the Zn-MOF-74 crystal surface after NP decoration. X-ray photoelectron spectroscopy confirmed the metal oxidation states of Zn and NPs. High-resolution transmission electron microscopy images proved the surface decoration of Zn-MOF-74 crystals with spherical metallic NPs with diameters between 2.4 and 9.8 nm.

Zn Oxide Nanoparticles and Fine Particles: Synthesis, Characterization and Evaluation of the Toxic Effect on Germination and Vigour of Solanum licopersicum L.

The micronutrient Zinc (Zn) is essential for the proper growth and development of crops. Zinc oxide nanoparticles (NPs) and fine particles are presented as an emerging alternative to more traditional fertilizers. In this study, the possible toxic effect of four laboratory-synthesized ZnO NPs and fine particles with different characteristics on tomato seed germination and vigor parameters was examined in comparison to bulk ZnO. Different metal precursors were used for the chemical synthesis of the particles: Zn(NO3)2 and ZnSO4, for particles named NIT-. and SUL-., respectively. In addition, the synthesis process was modified to obtain coated particles (denoted as UW-, NIT-UW and SUL-UW) and washed particles (denoted as W-, NIT-W and SUL-W). These particles were applied at different toxic doses (0, 1.4, 2.8, 5.6 and 11.2 g L−1). The results indicated that although the constant contact time between the ZnO particles did not affect the germination capacity of the seeds, it affected the growth of roots and hypocotyls, with a higher impact on the roots’ development. This toxicity was more evident from the lowest particle dose used, although it did not prevent radicle and hypocotyl elongation during the development period studied (14 days). The synthesized coated particles (NIT-UW, SUL-UW) generated high toxicity on radicle and hypocotyl development, and this effect was observed from the first days of contact with the particles. The observed toxic effects on radicle length were minimized by the application of bulk ZnO particles. In the case of hypocotyl growth, these minor toxic effects were observed by using NIT-W particles and bulk ZnO. The possibility of positive effects on seed germination and development (radicle and hypocotyl length) when in continuous contact with ZnO, whether in fine particles, nanoparticles, or bulk sizes, was excluded. Furthermore, no benefits on germination parameters were observed by suppressing the final washing step in the particle’s synthesis process, suggesting that particle coating did not provide any advantage for seed germination under these continuous contact conditions.

Confined-Coordination Induced Intergrowth of Metal-Organic Frameworks into Precise Molecular Sieving Membranes.

Metal-organic framework (MOF) membranes with rich functionality and tunable pore system are promising for precise molecular separation; however, it remains a challenge to develop defect-free high-connectivity MOF membrane with high water stability owing to uncontrollable nucleation and growth rate during fabrication process. Herein, we report on a confined-coordination induced intergrowth strategy to fabricate lattice-defect-free Zr-MOF membrane towards precise molecular separation. The confined-coordination space properties (size and shape) and environment (water or DMF) were regulated to slow down the coordination reaction rate via controlling the counter-diffusion of MOF precursors (metal cluster and ligand), thereby inter-growing MOF crystals into integrated membrane. The resulting Zr-MOF membrane with angstrom-sized lattice apertures exhibits excellent separation performance both for gas separation and water desalination process. It was achieved H2 permeance of ~1200 GPU and H2/CO2 selectivity of ~67; water permeance of ~8 L ⋅ m-2 ⋅ h-1 ⋅ bar-1 and MgCl2 rejection of ~95 %, which are one to two orders of magnitude higher than those of state-of-the-art membranes. The molecular transport mechanism related to size-sieving effect and transition energy barrier differential of molecules and ions was revealed by density functional theory calculations. Our work provides a facile approach and fundamental insights towards developing precise molecular sieving membranes.

Confined‐Coordination Induced Intergrowth of Metal–Organic Frameworks into Precise Molecular Sieving Membranes

AbstractMetal–organic framework (MOF) membranes with rich functionality and tunable pore system are promising for precise molecular separation; however, it remains a challenge to develop defect‐free high‐connectivity MOF membrane with high water stability owing to uncontrollable nucleation and growth rate during fabrication process. Herein, we report on a confined‐coordination induced intergrowth strategy to fabricate lattice‐defect‐free Zr‐MOF membrane towards precise molecular separation. The confined‐coordination space properties (size and shape) and environment (water or DMF) were regulated to slow down the coordination reaction rate via controlling the counter‐diffusion of MOF precursors (metal cluster and ligand), thereby inter‐growing MOF crystals into integrated membrane. The resulting Zr‐MOF membrane with angstrom‐sized lattice apertures exhibits excellent separation performance both for gas separation and water desalination process. It was achieved H2 permeance of ~1200 GPU and H2/CO2 selectivity of ~67; water permeance of ~8 L ⋅ m−2 ⋅ h−1 ⋅ bar−1 and MgCl2 rejection of ~95 %, which are one to two orders of magnitude higher than those of state‐of‐the‐art membranes. The molecular transport mechanism related to size‐sieving effect and transition energy barrier differential of molecules and ions was revealed by density functional theory calculations. Our work provides a facile approach and fundamental insights towards developing precise molecular sieving membranes.

Green synthesis of copper and iron nanoparticles from extracts of eucalyptus with their antimicrobial activities

Eco-friendly iron and copper nanoparticles were synthesized using masquerade and eucalyptus leaves extract as a reducing and stabilizing agents. Iron chloride heptahydrate (FeCl2.7H2O) and Copper sulphatepenta hydrate (CuSO4.5H2O) as metal precursors. It was characterized using UV visible, FTIR, XRD and SEM analysis. The UV result shows the highest peaks at 500 and 600 nm for iron and copper respectively. This is due to the surface plasma vibration of the phytochemical constituents present in the extract. FTIR shows presence of alkanoids and triterpenes, SEM shows the spherical granular with no well-defined morphology and mono dispersed structures for iron and copper nanoparticles respectively. It shows good antibacterial activity when tested against Escherichia-coli and Pseudomonas auredinosa (gram- negative), Staphylococcus aureus and Klebsella pneumonia (gram-positive).

Novel melatonin-producing Bacillus safensis EH143 mitigates salt and cadmium stress in soybean.

Recently, microorganism and exogenous melatonin application has been recognized as an efficient biological tool for enhancing salt tolerance and heavy metal detoxification in agriculture crops. Thus, the goal of this study was to isolate and evaluate a novel melatonin-producing plant growth promoting bacterium. With high-throughput whole genome sequencing, phytohormone measurements, expression profiling, and biochemical analysis, we can identify a novel PGPB that produces melatonin and unravel how it promotes soybean growth and development and protects against salt and Cd stress. We identify the melatonin synthesis pathway (tryptophan→tryptamine→serotonin melatonin) of the halotolerant (NaCl > 800 mM) and heavy metal-resistant (Cd >3 mM) rhizobacterium Bacillus safensis EH143 and use it to treat soybean plants subjected to Cd and NaCl stresses. Results show that EH143 will highly bioaccumulate heavy metals and significantly improve P and Ca2+ uptake and the K+/Na+ (93%↑under salt stress) ratio while reducing Cd uptake (49% under Cd stress) in shoots. This activity was supported by the expression of the ion regulator HKT1, MYPB67, and the calcium sensors CDPK5 and CaMK1 which ultimately led to increased plant growth. EH143 significantly decreased ABA content in shoots by 13%, 20%, and 34% and increased SA biosynthesis in shoots by 14.8%, 31%, and 48.2% in control, salt, and Cd-treated plants, upregulating CYP707A1 and CYP707A2 and PAL1 and ICS, respectively. The melatonin content significantly decreased along with a reduced expression of ASMT3 following treatment with EH143; moreover, reduced expression of peroxidase (POD) and superoxide dismutase (SOD) by 134.5% and 39% under salt+Cd stress, respectively and increased level of total amino acids were observed. Whole-genome sequencing and annotation of EH143 revealed the presence of the melatonin precursor tryptophan synthase (trpA, trpB, trpS), metal and other ion regulators (Cd: cadA, potassium: KtrA and KtrB, phosphate: glpT, calcium: yloB, the sodium/glucose cotransporter: sgIT, and the magnesium transporter: mgtE), and enzyme activators (including the siderophore transport proteins yfiZ and yfhA, the SOD sodA, the catalase katA1, and the glutathione regulator KefG) that may be involved in programming the plant metabolic system. As a consequence, EH143 treatment significantly reduced the contents of lipid peroxidation (O2-, MDA, and H2O2) up to 69%, 46%, and 29% in plants under salt+Cd stress, respectively. These findings suggest that EH143 could be a potent biofertilizer to alleviate NaCl and Cd toxicity in crops and serve as an alternative substitute for exogenous melatonin application.

Exceptional performance of Fe@carbon-rich nanoparticles prepared via hydrothermal carbonization of oil mill wastes for H2S removal

Carbon-encapsulated iron oxide nanoparticles (CE-nFe) have been obtained from an industrial waste (oil mill wastewater-OMW, as a carbonaceous source), and using iron sulfate as metallic precursor. In an initial step, the hydrochar obtained has been thermally activated under an inert atmosphere at three different temperatures (600 °C, 800 °C and 1000 °C). The thermal treatment promotes the development of core-shell nanoparticles, with an inner core of α-Fe/Fe3O4, surrounded by a well-defined graphite shell. Temperatures above 800 °C are needed to promote the graphitization of the carbonaceous species, a process promoted by iron nanoparticles through the dissolution, diffusion and growth of the carbon nanostructures on the outer shell. Breakthrough column tests show that CE-nFe exhibit an exceptional performance for H2S removal with a breakthrough capacity larger than 0.5–0.6 g H2S/gcatalyst after 3 days experiment. Experimental results anticipate the crucial role of humidity and oxygen in the adsorption/catalytic performance. Compared to some commercial samples, these results constitute a three-fold increase in the catalytic performance under similar experimental conditions.

Generalized Synthesis of Highly-Dispersed, Ultrafine Transition Metal Nanoparticles on Silica Spheres for Enhanced Optical Absorption.

Robust synthesis of ultrafine metal nanoparticles (ufMNPs) below 5nm with clean surfaces and strong optical absorption in the visible spectral range is challenging due to their instability originating from large surface-to-volume ratios. This work reports a general strategy involving two sequential steps: i) loading metal precursor ions onto the surface of silica nanospheres (SiOx NSs) by forming a uniform coating of metal oxyhydroxide [MOy(OH)z] through preferred surface acid-base reactions and ii) thermally reducing MOy(OH)z in forming gas at elevated temperatures to form ufMNPs evenly dispersed on the surface of SiOx NSs. The capability of this synthesis strategy is verified by loading ufMNPs of various transition metals and bimetallic combinations onto the SiOx NSs. The ufMNPs exhibit strong optical absorption enhanced by the optical scattering resonances in the SiOx NSs, which generate intense electric fields near the surface of the SiOx NSs. The SiOx NSs also support stabilizing the ufMNPs, which do not need additional organic capping reagents. The successful synthesis of SiOx-NS-supported ufMNPs with clean surfaces and enhanced optical absorption is promising for exploring the photocatalytic properties of ufMNPs.

Superparamagnetic iron oxide nanoparticles functionalized by biocompatible ligands with enhanced high specific absorption rate for magnetic hyperthermia

This study introduces a novel green nanocomposite system of iron oxide coated with secondary metabolites (Fe3O4@SM) and compares it with commonly used materials for hyperthermia cancer treatment. Fe3O4@SM magnetic nanoparticles were synthesized through a simple co-precipitation process using metal precursors, followed by heating in pressure reactor to obtain superparamagnetic nanoparticles (Hc = 36.5–54.1 Oe at 300 K). These nanoparticles were subsequently coated with plant-based phytochemicals. XRD analysis confirmed the presence of magnetite iron oxide nanoparticles. SEM images further confirmed the spherical shape of the synthesized nanoparticles, exhibiting a face-centered cubic (FCC) iron oxide structure with sizes ranging from 12±7–85±15 nm. Characterization through dynamic light scattering (DLS) and zeta potential (ζ) analysis demonstrated colloidal stability, with a polydispersity index (PDI) ranging from 0.226 to 0.436 and zeta potential values ranging from −29.761–1.85 mV. The surface of the nanoparticles was analyzed using GC-MS, which identified bioactive functional groups including ester (42.79 %), terpene (20.69 %), hydrocarbons (17.4 %), and carboxylic (12.37 %) compounds. Compared to Fe3O4 and Fe3O4@GO, Fe3O4@SM exhibited a higher rate of temperature increase within the therapeutic range, reaching Tmax = 45°C with a heating rate (dT/dt) of 0.273 °C/s and specific absorption rate (SAR) of 230.6 W/g at 304 kHz and 400 Oe. In vitro assays utilizing a triple negative breast cancer microenvironment confirmed the non-toxicity of these materials through a DNS assay. The developed nanoparticles offer dual mechanisms of action, combining thermal and chemo effects, making them promising candidates for hyperthermia cancer treatment.

Metal-organic framework gel derived magnetic hierarchical porous Fe-N-C catalyst as peroxymonosulfate activator for efficient degradation of amoxicillin via singlet oxygen-dominated nonradical pathway

The rational design of transition metal and nitrogen co-doped carbon-based catalysts for the efficient removal of antibiotics through non-radical pathway of peroxymonosulfate (PMS) activation has attracted widespread attention. Herein, a magnetic hierarchical porous Fe-N-C catalyst (FeBDC-NH2-800) was successfully constructed by pyrolyzing the hierarchical porous precursor metal–organic framework gel (FeBDC-NH2) consisting of nitrogen-containing ligands. Benefiting from the defective heterojunction structure, the catalyst exhibited effective and efficient degradation towards amoxicillin (AMX) by activating PMS to produce 1O2. The degradation of AMX was up to 97.4 % within 30 min, which was 2.48 and 2.16 times more than that of FeBDC-NH2/PMS and nanosized Fe3O4/PMS respectively. The high degradation performance could be maintained toward low pollutant concentration conditions and cycle experiments, manifesting its possibility for practical application. Combining the data of quenching experiments, electron spin resonance spectra, electrochemical experiments, X-ray photoelectron spectra and density functional theory calculation, the mechanism was revealed that radical pathway contributed little during degradation while singlet oxygen played a significant role. The cleavage of lattice oxygen and defective heterogeneous structure of FeBDC-NH2-800 contributed together to promote PMS for 1O2 production.