Alkali-free synthesis of hexagonal star-like Fe-ethylene glycol (Fe-EG) complex and subsequently decomposition to α-Fe2O3 and Fe3O4/α-Fe/C composites

Sodium salt promoted the generation of nano zero valent iron by carbothermal reduction: For activating peroxydisulfate to degrade antibiotic

Carbothermal reduction is a promising method for the industrial preparation of nano-zero-valent iron. Preparing it also involves very high pyrolysis temperatures, which leads to a significant amount of energy consumption. The temperature required for the preparation of nano-zero-valent iron by carbothermal reduction was reduced by 200 °C by the addition of sodium salt. Carbon-loaded nano zero-valent iron (Fe0/CB-Na) was prepared by carbothermal reduction through the addition of sodium salt. The results showed that Fe0/CB-Na@700 had the same activation performance as Fe0/CB@900 and the newly prepared nano-zero-valent iron. The addition of sodium salt promoted the transfer of oxygen from the iron oxide to the carbon structure during the roasting process so that the iron oxide was reduced to as much Fe0 as possible. Thus, sodium salts were optimized for the preparation of nano-zero-valent iron by carbothermal reduction through interfacial amorphization and oxygen transfer, thus reducing the preparation cost.

Realizing Ultrafast and Robust Sodium-Ion Storage of Iron Sulfide Enabled by Heteroatomic Doping and Regulable Interface Engineering

Fe-based sulfides are a promising type of anode material for sodium-ion batteries (SIBs) due to their high theoretical capacities and affordability. However, these materials often suffer from issues such as capacity deterioration and poor conductivity during practical application. To address these challenges, an N-doped Fe₇S₈ anode with an N, S co-doped porous carbon framework (PPF-800) was synthesized using a template-assisted method. When serving as an anode for SIBs, it delivers a robust and ultrafast sodium storage performance, with a discharge capacity of 489 mAh g^-1 after 500 cycles at 5 A g^-1 and 371 mAh g^-1 after 1000 cycles at 30 A g^-1 in the ether-based electrolyte. This impressive performance is attributed to the combined influence of heteroatomic doping and adjustable interface engineering. The N, S co-doped carbon framework embedded with Fe₇S₈ nanoparticles effectively addresses the issues of volumetric expansion, reduces the impact of sodium polysulfides, improves intrinsic conductivity, and stimulates the dominant pseudocapacitive contribution (90.3% at 2 mV s^-1). Moreover, the formation of a stable solid electrolyte interface (SEI) film by the effect of uniform pore structure in ether-based electrolyte produces a lower transfer resistance during the charge-discharge process, thereby boosting the rate performance of the electrode material. This work expands a facile strategy to optimize the electrochemical performance of other metal sulfides.

Synergic Temperature Effect of Star-like Monodisperse Iron Oxide Nanoparticles and Their Related Responses in Normal and Cancer Cells

Magnetic nanoparticle (MNP) anisotropy has been tailored by the preparation of MNPs having different shapes (star-like, cubic, and polyhedral) using a self-modified rapid hot-injection process. The surface modification of MNPs was performed through etidronic ligand grafting with a strong binding affinity to mixed metal oxides, ensuring sufficient colloidal stability, surface protection, and minimized aggregation and interparticle interactions. The heating effect was induced by contactless external stimulation through the action of an alternating magnetic field and NIR laser radiation (808 nm). The efficacy of the energy conversion was evaluated as a function of the particle shape, concentration, and external stimuli parameters. In turn, the most efficient star-like particles have been selected to study their response in contact with normal and cancer cells. It was found that the star-like MNPs (Fe₃O₄ SL-NPs) at 2 mg/mL concentration induce necrosis and significantly alter cell cycle progression, while 0.5 mg/mL can stimulate the antioxidative and anti-inflammatory response in normal cells. A biologically relevant heating effect leading to heat-mediated cell death was achieved at a 2 mg/mL concentration of star-like particles and was enhanced by the addition of ascorbic acid (AA). AA-mediated photomagnetic hyperthermia can lead to the modulation of the heat-shock response in cancer cells that depends on the genotypic and phenotypic variations of cell lines.

Fe/C materials prepared by one-step calcination of acidified municipal sludge and their excellent adsorption of Cr(VI)

Biochar derived from municipal sludge can be applied to adsorption. But it usually requires activation and pickling due to the generation of impurities such as metal oxide particles, which is uneconomical. Here, a facile strategy, acidification-one-step calcination, was developed and sludge-based Fe-C materials with good Cr(VI) removal effect were obtained by regulating the amount of hydrochloric acid. The results show that the adsorption capacity of Fe/C-5 (the best sample) for Cr(VI) was 150.84 mg g^-1. According to the Langmuir isotherm and pseudo-second-order kinetic model, the removal of Cr(VI) by Fe/C-5 is spontaneous and endothermic chemisorption process. In addition, Fe/C-5 has good ability to remove Cr(VI) under the interference of coexisting ions, and has good cycle stability. The removal of Cr(VI) by Fe/C-5 is considered to be synergistic process of adsorption and reduction. The Fe atoms were highly dispersed in Fe/C-5 and tightly bonded with C atoms, which not only strengthened the Cr(VI) adsorption by electrostatic attraction, but also activated the C atoms in the biochar material, so that the C atoms can reduce Cr(VI) to Cr(III) under acidic conditions. This may be due to the fact that acid pretreatment converted the iron in municipal sludge in the form of Fe-O/OH to free Fe³⁺ and entered the C lattice during the calcination process. In this work, Fe-C materials with excellent Cr(VI) adsorption capacity were prepared by one-step calcination method, which has important reference significance for the resource utilization of municipal sludge.