Iron Nanoparticles Research Articles

Single-Atom Iron Can Steer Atomic Hydrogen toward Selective Reductive Dechlorination: Implications for Remediation of Chlorinated Solvents-Impacted Groundwater.

Atomic hydrogen (H*) is a powerful and versatile reductant and has tremendous potential in the degradation of oxidized pollutants (e.g., chlorinated solvents). However, its application for groundwater remediation is hindered by the scavenging side reaction of H2 evolution. Herein, we report that a composite material (Fe0@Fe-N4-C), consisting of zerovalent iron (Fe0) nanoparticles and nitrogen-coordinated single-atom Fe (Fe-N4), can effectively steer H* toward reductive dechlorination of trichloroethylene (TCE), a common groundwater contaminant and primary risk driver at many hazardous waste sites. The Fe-N4 structure strengthens the bond between surface Fe atoms and H*, inhibiting H2 evolution. Nonetheless, H* is available for dechlorination, as the adsorption of TCE weakens this bond. Interestingly, H* also enhances electron delocalization and transfer between adsorbed TCE and surface Fe atoms, increasing the reactivity of adsorbed TCE with H*. Consequently, Fe0@Fe-N4-C exhibits high electron selectivity (up to 86%) toward dechlorination, as well as a high TCE degradation kinetic constant. This material is resilient against water matrix interferences, achieving long-lasting performance for effective TCE removal. These findings shed light on the utilization of H* for the in situ remediation of groundwater contaminated with chlorinated solvents, by rational design of earth-abundant metal-based single-atom catalysts.

Highly porous layered carbon nanocomposites from the self-assembly of a poly(amic acid) for efficient oxygen reduction reaction catalysis

Porous layered carbon nanomaterials play important role in the efficient loading of electroactive substances for high performance energy conversion techniques. Herein, an intramolecular cyclization induced self-assembly (ICISA) strategy is proposed to prepare three-dimensional highly porous layered carbon nanostructures (LCs) for efficient loading of various transition metal nanoparticles for oxygen reduction reaction (ORR) catalysis. The amphiphilic alternating copolymer poly(amic acid) (PAA) is synthesized by the stepwise polymerization of hydrazine hydrate and pyromellitic dianhydride. Upon heating above 160 °C, the intramolecular cyclization reaction occurs, leading to the formation of rigid, crystalline and non-soluble polyimide segments in the backbone, which induces the self-assembly of the polymer to form dumbbell-shaped assemblies with a high solid content of 15%. After pyrolysis in a nitrogen atmosphere, LCs are obtained. Cobalt (Co), iron (Fe) and FeCo nanoparticles can be efficiently loaded, noted as Co@LCs, Fe@LCs and FeCo@LCs, respectively. The ORR catalytic performance of the catalysts is evaluated to give half wave potentials of 0.791, 0.787 and 0.812 V, and limit current densities of 4.92, 4.73 and 4.71 mA cm−2 for Co@LCs, Fe@LCs and FeCo@LCs, respectively. Overall, we propose an ICISA strategy to facilely prepare three-dimensional carbon nanomaterials with highly porous layered structure for efficient ORR catalysis.

Синергічний вплив гентаміцину та наночасток оксиду заліза на ген phzM синьогнійної палички

The increased use of iron-containing nanoparticles and green synthesis nanoparticles is beneficial and less harmful to the environment and human health. Working antimicrobial peptide functions by inhibiting the virulence factor of Pseudomonas aeruginosa, which is the essential mechanism of drug resistance by possessing an efflux pump important virulent factor. The main aim of the research was to study the effects of synergistic action of gentamicin (GNT) and iron nanoparticles (IONps) to solve the problem of multidrug-resistant P. aeruginosa. Methods. The isolation and identification of multidrug-resistant P. aeruginosa from burns and wound infections were carried out using the VITEK 2 system, and the phzM genes were detected in all the strains. The effectiveness of IONps and their role in reducing phzM gene expression were investigated. Results. The characterization of IONps biologically manufactured using a wavelength spectrum UV-vis spectrophotometer (maximum peak at 600 nm) and tests of atomic force microscopy showed that their diameter reached 34 nm. An electron microscope examination revealed that the produced particles were spherical, indicating good homogeneity and quality of the IONps. The results showed significant down-regulation changes in phzM expression after treatment with GNT and IONps. The result of qRT-PCR in this study revealed that the fold change in the expression of the phzM gene was downregulated in response to the IONps (8µg/mL) + GNT (16µg/mL) combination. Conclusions. One of the justifications for using P. aeruginosa in preparing IONps is that this bacteria needs iron as a growth promoter, which helps in the formation of IONps. The inhibitory effect on the efflux pump gene expression may represent a potential strategy for controlling P. aeruginosa infections.

Black seed assisted synthesis, characterization, free radical scavenging, antimicrobial and anti-inflammatory activity of iron oxide nanoparticles

Iron nanoparticles comprise a significant class of inorganic nanoparticles, which discover applications in various zones by prudence of their few exciting properties. This study achieved the green synthesis of iron oxide nanoparticles (IONPs) by black cumin seed (Nigella sativa) extract, which acts as a reducing and capping agent. The iron nanoparticles and black cumin extract were synthesized in three different concentrations: (01:01, 02:04,01:04). UV-visible spectroscopy, XRD, FTIR, and AFM characterized the synthesized iron oxide nanoparticles. UV-visible spectra show the maximum absorbance peak of 01:01 concentration at 380 nm. The other concentrations, such as 02:04, peaked at 400 nm and 01:04 at 680 nm, confirming the formation of iron oxide nanoparticles. AFM analysis reveals the spherical shape of iron oxide nanoparticles. The XRD spectra reveal the (fcc) cubic crystal structure of the iron oxide nanoparticles. The FTIR analysis’s peaks at 457.13, 455.20, and 457.13 cm-1 depict the characteristic iron nanoparticle synthesis. The black cumin extract-mediated iron oxide nanoparticles show substantial antibacterial, antifungal, antioxidant and anti-inflammatory activity in a dose-dependent manner.

Impact of iron oxide alginate berbamine nanocomposites on the pre-metastatic microenvironment of human bladder cancer cells through ROS-mediated mitochondrial depolarization

The main objective of the current study was to synthesize, characterize, and application of an anticancer agent based on iron oxide nanoparticles (NPs) synthesized in the presence of berbamine and alginate to modulate the pre-metastatic ecological niche of human bladder cancer cells by inducing ROS-mediated mitochondrial depolarization. The environmentally friendly synthesized nanoparticles were analyzed using SEM and TEM imaging, VSM, XRD, DLS, Zeta sizing, photoluminescence, EDX, and UV–Vis spectroscopy techniques. The findings indicated that the nanoparticles were smaller than 100 nm, displayed consistent spherical morphology, and were evenly monodispersed in size. We observed that the hydrodynamic size of the synthesized NPs was around 247.8 nm and the zeta potential was −32.1 mV. EDX analysis showed that the fabricated NPs composed of Iron (70.9 % of Mass) and O (29.1 % of Mass). The XRD analysis showed that the pattern of the NPs is matched with JCPDS card number 82–1533. The VSM analysis revealed that the NPs displayed superparamagnetic properties when exposed to a magnetic field. Results from the anticancer investigations demonstrated that the NPs caused a dose and time-dependent lethal impact on T24 cells, while showing no significant toxicity on SV-HUC-1 cells, highlighting their biocompatibility. The anticancer mechanism was evaluated using acridine orange/ethidium bromide, DCFH-DA, JC-1 staining, and wound-healing/scratch assay. The results demonstrated that the cells underwent apoptosis instead of necrosis, attributed to ROS-triggered mitochondrial depolarization. Additionally, the nanoparticles inhibited the cells' migratory capabilities. These results suggest that the environmentally friendly produced iron nanoparticles have promising potential as a strong anticancer treatment.

Utilization of Orange Peel Waste for the Green Synthesis of Iron Nanoparticles and its Application to Stimulate Growth and Biofortification on Solanum lycopersicum

Utilization of Orange Peel Waste for the Green Synthesis of Iron Nanoparticles and its Application to Stimulate Growth and Biofortification on Solanum lycopersicum

Highly selective recovery of rare earth elements from mining wastewater using phyto-synthesized biochar dispersed iron nanoparticles

Recovery of rare earth elements (REEs) from secondary sources such as mining wastewater has attracted much recent attention due to the rising global demand for REEs and the need to environmentally protect potentially contaminated mine sites. One significant issue it that most adsorbents proposed for removal and/or recovery of REEs are not generally selective for REEs. In this study, biochar dispersed iron nanoparticles synthesized using a plant extract (BC-FeNPs) were successfully used for the selective recovery of REEs from mining wastewater, where the Kd values were Nd(III) (918 mL∙g−1), Eu(III) (1253 mL∙g−1), Tb(III) (1119 mL∙g−1), Dy(III) (1032 mL∙g−1), Lu(III) (1898 mL∙g−1), compared to only 23.9 mL∙g−1 for Zn(II). The maximum adsorption efficiency of REEs for the composite was higher than the constituent parts being 88.4 % for BC-FeNPs, but only 8.72 % for biochar and 82.4 % for FeNPs, respectively. FTIR, XPS and Zeta potential analysis suggested that the observed selective adsorption of REEs, involved interactions of REEs with O and N, as well as ion-exchange with H+ from the biochar and capping layer, as well as electrostatic interactions. The desorption efficiency of bound REEs from BC-FeNPs was > 85 % when using acetic acid, and was attributed to efficient competitive ion exchange. Pearson correlation analysis further demonstrated that the adsorption mechanism included ion complexation, ion exchange and electrostatic adsorption, while the desorption mechanism was mainly via ion exchange. Overall, BC-FeNPs has significant potential to practically recover REEs from mining wastewater having demonstrated excellent reusability after five adsorption–desorption cycles.

Preparation, structural and surface characteristics of hybrid nanomaterials for optical devices

Nanocomposite samples were made using the polymerization fabrication method to prepare films consisting of iron (III) oxide (Fe2O3) and poly(4-chloroaniline) (P(4ClAni)). The samples were characterized using energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction, photoluminescence and transmission electron microscopy (TEM) to confirm that P(4ClAni)/iron (III) oxide nanocomposite films had been successfully fabricated. The EDX analysis confirmed the predicted chemical composition of P(4ClAni)/iron (III) oxide. The TEM showed spherical nanoparticles of iron (III) oxide with almost homogeneous and uniform sizes between 30 and 40 nm. The effect of iron (III) oxide on optical properties in the wavelength range 190–1200 nm was recorded. The dispersion energy values for P(4ClAni) were found to increase from 0.72 to 0.81, 0.96 and 1.21 eV when the concentration of iron (III) oxide was increased to 3, 6 and 9%, respectively. The relaxation time decreased from 4.46 × 10−6 to 3.52 × 10−6 s as the concentration of iron (III) oxide increased from 3 to 9%. Strong interactions between P(4ClAni) and iron (III) oxide were supported by the obtained results of this work. The obtained data indicate that the prepared P(4ClAni)/iron (III) oxide nanocomposites can be applied in several areas of optoelectronics.

Biofabrication of Centella asiatica mediated metal (Silver and Iron) nanoparticles and their enhanced antimicrobial, anticancer activity in retinoblastoma Y79 cancer cells

In recent years, metallic nanoparticles have played a significant role in nanotechnology and bio fabrication, being considered an alternative to antibiotics due to their feasibility for use in both bacterial detection and infection prevention. Moreover, recent studies have demonstrated the green process of developing nanoparticles with anticancer activity against many human cancer cell lines. In the current investigation, the biogenic synthesis of silver and iron nanoparticles using the aqueous leaf extract of Centella asiatica was performed. The leaf extracts underwent characterization for antioxidant activity, TLC analysis, phytochemical analysis, and GC-MS analysis of Centella asiatica. The leaf extracts revealed the antioxidant potential of the phytoconstituents, namely phenolic and flavonoid contents, responsible for the anticancer activity. The synthesized silver and iron nanoparticles were analysed using various techniques, including UV-Vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, and transmission electron microscopy. Confirmation of silver and iron nanoparticle formation was achieved through UV-Vis absorption spectra, showing absorption peaks at 362 nm and 342 nm, respectively. Fourier transform infrared spectroscopy analysis confirmed the biological moieties involved in synthesis and stability. X-ray diffraction (XRD) analysis verified the crystallinity of the nanomaterials, while scanning electron microscopy depicted spherical shapes for silver nanoparticles and similarly round shapes for iron nanoparticles. EDS analysis revealed 87.12 % silver and 40.12 % iron content in the respective nanoparticles. TEM imaging displayed predominantly spherical silver nanoparticles, sized at 50 nm. The antimicrobial efficacy of the biosynthesized silver and iron nanoparticles was evaluated using the well diffusion method, along with the determination of the minimum inhibitory concentration. Results indicated moderate effectiveness of silver nanoparticles against Escherichia coli (7±0.036) and Aspergillus niger (5±0.034) compared to iron nanoparticles. The minimum inhibitory concentrations against Staphylococcus aureus were 46.51–86.74 % for silver nanoparticles and 42.79–77.44 % for iron nanoparticles. The anticancer effect was evaluated using human retinoblastoma (Y79) cell lines. The cytotoxicity study using the MTT assay revealed that Centella asiatica-mediated silver nanoparticles exhibited significant cytotoxicity to human retinoblastoma cells, with a low IC50 value of 49.56 μg/ml. Based on the results, it is feasible to infer that biofabricated nanoparticles could potentially serve as antibacterial and antifungal compounds. Furthermore, the synthesized silver nanoparticles, followed by iron nanoparticles, showed high effectiveness against human retinoblastoma cancer cells, indicating potential for future drug discovery to inhibit retinoblastoma cancer for biomedical applications.

Перспективні методи лікування передчасної недостатності яєчників

Premature ovarian failure (PОF) in women under 40 is a medical condition in which ovarian follicles are exhausted and cease to function normally as both reproductive and endocrine organs. This condition often leads to infertility because it is associated with hypoestrogenia, which causes menstrual irregularities and pregnancy failure. Decreased estrogen secretion also causes many menopausal symptoms, such as hot flashes, night sweats, and insomnia. In addition, the longterm consequences of POF increase the risk of lifelong skeletal vulnerability and cardiovascular as well as neurocognitive disorders. The purpose of the work is to collect, analyze and summarize data from recent years about promising methods of treatment of premature ovarian failure, namely about autologous ovarian tissue transplantation, creation of artificial ovaries and oocytes, treatment with iron nanoparticles, intraovarian injections of autolytic platelet-rich plasma. It should be noted that premature ovarian failure (POF) differs from menopause in that ovarian failure may not be permanent; in such patients with POF, pregnancy is spontaneous and occurs infrequently. Our analysis and summarization of data from recent years suggests that 1) because autologous ovarian tissue transplantation requires tissue collection, this method is generally applicable to a specific patient group, women who are expected to have ovarian failure after cancer therapy, and a group of patients who experience gamete depletion as a result of a prognosis or even a diagnosis of POF. Ovarian tissue transplantation, which has been known for two decades, still has significant risks and technical limitations and is not recognized as a reliable method in clinical practice. 2) the concept of "artificial ovary" remains at the stage of experimental development of cellular systems in animals. Whereas, by creating artificial oocytes from several different sources (cell types), live birth has already been achieved in animals. And expectations are aimed at a steady progression to their clinical use in humans. 3) the use of zero-valent iron nanoparticles under the conditions of experimental immune complex failure has a certain corrective effect on the disorder of ovarian function. There is reason to believe that the effect of the treatment with zero-valent iron nanoparticles is fundamentally different from the macroscopic one in the effects on cells and, apparently, in the mechanisms of action - which requires further study. 4) treatment with platelet-rich plasma (PRP) remains an invasive ultrasound-guided procedure with risks that are not yet fully understood. At this point, PRP should still be considered an experimental procedure for patients with POF (premature ovarian failure). It is relevant to continue research on the influence of PRP components on the ovary, to evaluate the effect of the PRP concentration, which could play a key role in the proliferation and differentiation of mesenchymal cells; and to establish the optimal time intervals between PRP procedures, the volume treatment, and the maximum and minimum number of such procedures. In general, the proposed promising methods (autologous ovarian tissue transplantation, creation of artificial ovaries and oocytes, use of nanomaterials (iron nanoparticles), intraovarian injections of autolytic platelet-rich plasma) are achievements in biomedical engineering aimed at overcoming infertility, associated with premature ovarian failure.

Optimizing antimicrobial efficacy and ammonia sensing in a novel carboxymethyl tamarind kernel gum/Fe nanocomposite

Iron nanoparticles were synthesized utilizing Carboxymethyl tamarind kernel gum (CMTKG), which acted as both a reducing and stabilizing agent. Through an in situ co-precipitation method, CMTKG/FeO nanocomposites were synthesized, employing epichlorohydrin as a cross-linking agent. Characterization of the obtained CMTKG/FeO nanocomposites was conducted through various techniques including Scanning Electron Microscopy (SEM), Dynamic light scattering (DLS), Ultraviolet spectroscopy, Fourier transform infrared (FTIR), Thermal analysis (TGA), and X-ray diffraction analysis (XRD), revealing an average size of 60–90 nm. The application of these nanocomposites was explored in the sensing of ammonia in an aqueous medium at room temperature, demonstrating a noticeable change in the intensity of the surface plasmon resonance peak with increasing ammonia concentration, resulting in a shift from 313 nm to 331 nm. Additionally, the antimicrobial efficacy of the synthesized CMTKG/FeO nanocomposites was evaluated against urinary tract isolates including Pseudomonas aeruginosa, E. coli, and Enterococcus faecalis. Interestingly, the nanocomposites exhibited significant activity specifically against Enterococcus faecalis, manifesting a zone of inhibition measuring 12.4±0.5 mm.

The effect of initial pressure and atomic concentration of iron nanoparticles on thermal behavior of sodium sulfate/magnesium chloride hexahydrate nanostructure by molecular dynamics simulation

Thermal energy storage (TES) is one of the uses of phase change material (PCM). The primary factor contributing to this capability is the elevated latent heat of melting present in these materials. The current study investigates the effect of initial pressure (IP) (ranging from 1 to 5 bar), and atomic ratio (AR) of Iron nanoparticles (NPs) (Fe = 1, 2, 3, and 5 %) on the thermal behavior (TB) and phase transition process of sodium sulfate/Magnesium chloride hexahydrate (Na2SO4/MgCl2·6H2O) nanostructures as PCMs using molecular dynamics (MD) simulation. The simulated PCM was positioned inside a spherical atomic channel composed of iron. The TB of simulated nanostructures was examined by reporting changes in viscosity (Vis), thermal conductivity (TC), and phase transition time (PTT). The results reveal that by increasing IP from 1 to 5 bar, the PTT reaches from 3.50 to 3.61 ns, and the TC decreases from 1.03 to 0.94 W/m.K. The results show that adding 3 % of Fe NPs was the optimal ratio to improve the TB of the Na2SO4/MgCl2·6H2O-Fe NP. By raising the ratio of Fe NPs from 1 to 3 %, Vis slightly decreased from 4.31 to 4.22 mPa.s. In comparison, adding more Fe NPs with 5 % ratio raised the Vis to 4.30 mPa.s. According to the results, increasing the IP decreased the distance among the particles. So, the attraction among particles increased, leading to greater adhesion and Vis. By increasing the IP, the distance among atoms decreases, and the space between NPs and atoms in the simulation box decreases. Consequently, NP movement and fluctuations decrease, and collisions decrease. The results of this simulation will be effective in heating–cooling and ventilation systems, automotive industries, textile industries, and so on.

In-situ constructing an innovative and versatile nanotraps for incorporation of zero–valent iron nanoparticles into zeolite imidazole framework–8 towards high efficient detoxification and imprisonment of U(VI) and Se(IV) from water via a combination study of capture performance and underlying mechanism aspects

This work reported an in-situ constructing of innovative and versatile nanotraps (NZVI/ZIF–8) namely incorporation of zero–valent iron nanoparticles (NZVI) into zeolite imidazole framework–8 (ZIF–8), and the application of the as-constructed NZVI/ZIF–8 in high efficient detoxification and imprisonment of U(VI) and Se(IV) from wastewater. The results demonstrated that controllable incorporation of NZVI with ZIF–8 used advantages of each component to generate an emphatic boosted interaction in U(VI)/Se(IV) imprisoning. The kinetic adsorption for U(VI)/Se(IV) imprisoned onto NZVI/ZIF–8 was described by pseudo-second-order model well, and the adsorption isotherms followed the Langmuir model better. Thermodynamic analysis (ΔG < 0, ΔS > 0, ΔH > 0) demonstrated that U(VI)/Se(IV) imprisoned onto NZVI/ZIF–8 was endothermic and spontaneous. XPS measurements unveiled that NZVI/ZIF–8 imprisoned U(VI)/Se(IV) by synergistic mechanism of adsorption and reduction. The N–containing functional groups on ZIF–8 was primarily responsible for adsorption, while Fe(0) and surface enriched Fe(II) from NZVI predominantly contributed to reductive conversion of U(VI)/Se(IV) into U(IV)/Se(0). In a word, ZIF-8 played an important role in imprisonment of U(VI)/Se(IV) onto the as-constructed NZVI/ZIF–8 nanotraps with intensified reactivity in comparison with naked NZVI. The findings revealed that the NZVI/ZIF–8 nanotraps would be superb scavengers towards U(VI)/Se(IV), and implied a bright future in potential application in nuclear waste management.

Influence of γ-Fe2O3 Nanoparticles Added to Gasoline–Bio-Oil Blends Derived from Plastic Waste on Combustion and Emissions Generated in a Gasoline Engine

The environmental pressure to reduce the use of fossil fuels such as gasoline generates the need to search for new fuels that have similar characteristics to conventional fuels. In this sense, the objective of the present study is the use of commercial gasoline in mixtures with pyrolytic oil from plastic waste and the addition of γ-Fe2O3 nanoparticles (NPs) in a spark ignition engine to analyze both the power generated in a real engine and the emissions resulting from the combustion process. The pyrolytic oil used was obtained from thermal pyrolysis at low temperatures (450 °C) of a mixture composed of 75% polystyrene (PS) and 25% polypropylene (PP), which was mixed with 87 octane commercial gasoline in 2% and 5% by volume and 40 mg of γ-Fe2O3 NPs. A standard sample was proposed, which was only gasoline, one mixture of gasoline with bio-oil, and a gasoline, bio-oil, and NPs mixture. The bio-oil produced from the pyrolysis of PS and PP enhances the octane number of the fuel and improves the engine’s power performance at low revolutions. In contrast, the addition of iron NPs significantly improves gaseous emissions with a reduction in emissions of CO (carbon monoxide), NOx (nitrogen oxide), and HCs (hydrocarbons) due to its advantages, which include its catalytic effect, presence of active oxygen, and its large surface area.

Nano iron loaded algal biomass: For better yield, amino acid and iron content in rice – A ‘nano-phycofertilizer’

The iron nano particles (INPs) loaded algal biomass can stimulate plant growth, leading to improved crop yields and quality. In this article, we have explored the efficacy of INPs-loaded biomass of Ulva intestinalis as ‘Nano-Phyco-Fertilizer (NPF)’ for rice cultivation. In situ INPs synthesis by Ulva biomass was spontaneous, turning the green thallus to brown due to the deposition of a large amount of intracellular INP within 24 h in dark conditions. The synthesized INPs was characterized as spindle-shaped with ferromagnetic properties by TEM analysis. The INPs-loaded algal biomass was dried, dusted, and applied to soil as NPF. Additionally, algal biomass without iron and free INPs were also tested separately and compared to NPF. The synergistic combination of algae and INPs in fertilizer formulations is a novel work and it offers several advantages over conventional fertilizers. As a result, after the application of NPF, the heights and grain yield of rice plants increased by 40 % and 2.5 times respectively. Moreover, the essential amino acid and iron content in rice grains showed a significant increase by 20–40 % and 45 % respectively upon NPF application, as compared to that of rice crops with conventional agricultural practice. The integration of algal and INP-based fertilizers represents a sustainable and innovative approach to meet the growing demands of global agriculture. As a result, it can be concluded that NPF shows significant enhancement in the growth and productivity of rice plant cultivation and holds immense promise in ensuring food security and mitigating the environmental impacts associated with conventional fertilization malpractices.

Removal of ciprofloxacin by biosulfurized nano zero-valent iron (BP–S-nZVI) activated peroxomonosulfate: Influencing factors and degradation mechanism

Agglomeration and passivation restrict the using zero-valent iron nanoparticles (nZVI). Enhancing the reactivity of nZVI is often accomplished by sulfurization. In this work, nZVI was sulfurized using SRB to produce biosulfurized nano zero-valent iron (BP–S-nZVI), which was then utilized as a catalyst to investigating its performance in an advanced oxidation process based on activated peroxomonosulfate (PMS). When the S/Fe was 0.05, 0.4 g/L of catalyst and 0.5 mM PMS were added to a 20 mg/L ciprofloxacin solution. In 120 min, a 90.4% clearance rate was reached. When the initial pH of the solution was within the range of 3–11, all exhibited acceptable degradation performance and were minimally affected by co-existing anions. In this activation system, hydroxyl, superoxide and sulfate radicals (•OH, O2•− and SO4•−, respectively) have been proven to be the main active species. Seven intermediates in the degradation process of CIP were identified by LC-MS analysis and two possible degradation pathways were proposed. In addition, the degradation rate of CIP was still able to reach 87.0% after five cycles, and the removal rate remained unchanged in the CIP solution with actual water samples as background. This study demonstrated that BP-S-nZVI as a catalyst for the activation of PMS for CIP degradation can still show good reactivity, which provides more possibilities for the practical application of BP-S-nZVI in the degradation of pollutants.

Transformation of the diamond surface with a thin iron coating during annealing and transport properties of the formed conductive layer

In our study, we annealed polycrystalline diamond films with nanometer-thick iron coatings. Based on analysis of X-ray photoelectron spectroscopy data the presence of two catalytic processes was suggested. One is the continuous absorption of sp3 carbon by iron nanoparticles with subsequent extrusion of the sp2 phase from the formed iron carbide, which leads to the creation of deep tracks into the diamond bulk that are filled with graphite stacks. The other process involves a thin layer of iron carbide on the surface and results in the creation of sp2 layers, which are made up of fused graphene-like patches and are oriented mainly along the surface of the diamond film. For the sample annealed at 800 °C for 1 h, the sp2 layers formed exhibit semi-metallic conductivity with quantum corrections caused by disorders. At the same time, no evidence of iron contribution in conductivity of the annealed Fe-coated film was detected, implying that upon transforming the diamond, iron moved quite deep into the bulk. In addition, the formed conductive layer on the diamond surface shows mechanical stability, ensuring the reproducibility of conductivity measurements even after six months of storage in air. The study has revealed the potential for targeted metal-assisted formation of sp2 carbon-based conducting pathways on diamond surfaces for electronic devices.

In-flight iron ore reduction and nanoparticle formation in an atmospheric pressure hydrogen microwave plasma

The in-flight reduction of iron ore particles using an atmospheric pressure hydrogen plasma is investigated. Iron ore particles with a size less than 75 µm are aerosolized and carried with an argon-hydrogen (90%–10%) gas mixture through an atmospheric pressure microwave plasma. After the treatment, the collected particles are observed to follow three distinct populations: (i) fully reduced nanoparticles, (ii) partially reduced spheres, larger than the feedstock, and (iii) partially melted, partly reduced agglomerates. A model is developed to explain the possible mechanism for the origin of the three populations. The nanoparticles (i) are found to be likely formed from the previously evaporated material whereas the particles (ii) and (iii) result from the partial/complete melting of the particles and agglomerates flowing through the reactor. The gas temperature is estimated to be more than 2000 K, which enables the rapid melting, evaporation, and reduction of these particles within residence times of only a few 10 ms.

Facile synthesis of iron nanoparticles from Camellia Sinensis leaves catalysed for biodiesel synthesis from Azolla filiculoides

Recent years have seen an increase in research on biodiesel, an environmentally benign and renewable fuel alternative for traditional fossil fuels. Biodiesel might become more cost-effective and competitive with diesel if a solid heterogeneous catalyst is used in its production. One way to make biodiesel more affordable and competitive with diesel is to employ a solid heterogeneous catalyst in its manufacturing. Based on X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FTIR), the researchers in this study proved their hypothesis that iron oxide core–shell nanoparticles were generated during the green synthesis of iron-based nanoparticles (FeNPs) from Camellia Sinensis leaves. The fabrication of spherical iron nanoparticles was successfully confirmed using scanning electron microscopy (SEM). As a heterogeneous catalyst, the synthesised catalyst has shown potential in facilitating the conversion of algae oil into biodiesel. With the optimal parameters (0.5 weight percent catalytic load, 1:6 oil—methanol ratio, 60 °C reaction temperature, and 1 h and 30 min reaction duration), a 93.33% yield was attained. This may be due to its acid–base property, chemical stability, stronger metal support interaction. Furthermore, the catalyst was employed for transesterification reactions five times after regeneration with n-hexane washing followed by calcination at 650 °C for 3 h.

Use of Zero-Valent Iron Nanoparticles (nZVIs) from Environmentally Friendly Synthesis for the Removal of Dyes from Water—A Review

This review article addresses the increasing environmental concerns posed by synthetic dyes in water, exploring innovative approaches for their removal with a focus on zero-valent iron nanoparticles (nZVIs) synthesized through environmentally friendly methods. The article begins by highlighting the persistent nature of synthetic dyes and the limitations of conventional degradation processes. The role of nanoparticles in environmental applications is then discussed, covering diverse methods for metallic nanoparticle production aligned with green chemistry principles. Various methods, including the incorporation of secondary metals, surface coating, emulsification, fixed support, encapsulation, and electrostatic stabilization, are detailed in relation to the stabilization of nZVIs. A novel aspect is introduced in the use of plant extract or biomimetic approaches for chemical reduction during nZVI synthesis. The review investigates the specific challenges posed by dye pollution in wastewater from industrial sources, particularly in the context of garment coloring. Current approaches for dye removal in aqueous environments are discussed, with an emphasis on the effectiveness of green-synthesized nZVIs. The article concludes by offering insights into future perspectives and challenges in the field. The intricate landscape of environmentally friendly nZVI synthesis has been presented, showcasing its potential as a sustainable solution for addressing dye pollution in water.