Nano-Magnetic NiFe2O4 and Its Photocatalytic Oxidation of Vanillyl Alcohol-Synthesis, Characterization, and Application in the Valorization of Lignin

Synthesis of spinel Nickel Ferrite (NiFe2O4)/CNT electrocatalyst for ethylene glycol oxidation in alkaline medium

Nickel-iron-based spinel oxide was prepared and supported on multi-walled carbon nanotubes to enhance the electrochemical oxidation of ethylene glycol in an alkaline medium. NiFe2O4 was prepared using facile sol-gel techniques. Then the prepared material was characterized using different bulk and surface techniques like powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmitted electron microscope (TEM). Different electrodes of NiFe2O4/CNT ratios were prepared to find out the optimum spinel oxide/CNT ratio. The activity of the metal spinel oxides composite was characterized toward ethylene glycol conversion by different electrochemical techniques like cyclic voltammetry (CV), Chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The modified electrode reached an oxidation current of 43 mA cm-2 in a solution of 1.0 M ethylene glycol and 1.0 M NaOH. Furthermore, some kinetics parameters (like diffusion coefficient, and rate constant) were calculated to evaluate the catalytic performance. Additionally, the electrode showed extreme stability for long-term ethylene glycol oxidation.

Magnetic nanoparticle-based combination therapy: Synthesis and in vitro proof of concept of CrFe2O4- rosmarinic acid nanoparticles for anti-inflammatory and antioxidant therapy

Magnetic drug delivery systems using nanoparticles present a promising opportunity for clinical treatment. This study explored the potential anti-inflammatory properties of RosA- CrFe2O4 nanoparticles. These nanoparticles were developed through rosmarinic acid (RosA) co-precipitation via a photo-mediated extraction technique. XRD, FTIR, and TEM techniques were employed to characterize the nanoparticles, and the results indicated that they had a cubic spinel ferrite (FCC) structure with an average particle size of 25nm. The anti-inflammatory and antioxidant properties of RosA- CrFe2O4 nanoparticles were evaluated by using LPS-induced raw 264.7 macrophages and a hydrogen peroxide scavenging assay, respectively. The results showed that RosA- CrFe2O4 nanoparticles had moderate DPPH scavenging effects with an IC50 value of 59.61±4.52μg/ml. Notably, these nanoparticles effectively suppressed the expression of pro-inflammatory genes (IL-1β, TNF-α, IL-6, and iNOS) in LPS-stimulated cells. Additionally, the anti-inflammatory activity of RosA- CrFe2O4 nanoparticles was confirmed by reducing the release of secretory pro-inflammatory cytokines (IL-6 and TNF-α) in LPS-stimulated macrophages. This investigation highlights the promising potential of Phyto-mediated CrFe2O4-RosA as an anti-inflammatory and antioxidant agent in biomedical applications.

Peracetic acid activated by nickel cobaltite as effective oxidizing agent for BPA and its analogues degradation

The presented research concerns the use of nickel cobaltite nanoparticles (NiCo2O4 NPs) for the heterogeneous activation of peracetic acid and application of NiCo2O4-PAA system for degradation 10 organic micropollutants from the group of bisphenols. The bisphenols removal (initial concentration 1 μM) process was optimized by selecting the appropriate process conditions. The optimal amount of catalyst (115 mg/L), peracetic acid (PAA) concentration (7 mM) and pH (7) were determined using response surface analysis in the Design of Experiment. Then, NiCo2O4 NPs were used to check the possibility of reuse in subsequent oxidation cycles. The work also attempts to explain the mechanism of oxidation of the studied micropollutants. The participation of the sorption process on the catalyst was excluded and based on the experiments with radical scavengers it can be concluded that the oxidation proceeds in a radical pathway, mainly with participation of O2•- radicals. Experiments conducted in real water matrices exhibit low impact on degradation efficiency. Toxicity tests with green alga Acutodesmus obliquus and aquatic plant Lemna minor showed that post-reaction mixture influenced growth and the content of photosynthetic pigments in concentration dependent manner.

Hybrid Mesoporous Carbon/Copper Ferrite Electrode for Asymmetric Supercapacitors

Asymmetric supercapacitors (ASCs) with two dissimilar electrodes are known to exhibit relatively moderate energy and power densities. If electrodes derived from earth-abundant materials or renewable resources such as lignocellulosic biomass (LCB) are used for fabrication, energy storage systems are expected to become less expensive and more sustainable. Hybrid electrode materials have advantages such as higher surface area, better chemical stability, and superior energy density. This study reports on the synthesis of a novel hybrid electrode material containing porous carbon (POC) and copper ferrite, which is designated as POC@Cu-ferrite, and its electrochemical performance in ASC configuration. Corn stover derived hydrochar is utilized for the sol-gel synthesis of POC@Cu-ferrite hybrid material using earth-abundant Cu and Fe-based precursors. This material is characterized using X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) surface area analyzer, and scanning and transmission electron microscopy (SEM/TEM). As-synthesized Cu-ferrite is found to contain 89.2% CuFe2O4 and 10.8% Fe2O3, whereas other phases such as Fe3O4, CuFeO2, and CuO are observed for the POC@Cu-ferrite. BET-specific surface area (SSA) and pore volume of POC@Cu-ferrite are observed as 1068 m2/g and 0.72 cm3/g, respectively. POC@Cu-ferrite hybrid electrode is used with POC opposite electrode to fabricate ASC, which is tested using Gamry G-300 potentiostat/galvanostat/ZRA to obtain cyclic voltammetry (CV) profiles and galvanostatic charge-discharge (GCD) plots. ASC is also prepared using Cu-ferrite and POC materials and its specific capacitance and stability are compared with ASCs prepared with POC@Cu-ferrite and POC or graphene nanoplatelets (GNPs) electrodes. POC@Cu-ferrite hybrid electrode is found to be superior with a 2-fold higher capacitance and significant electrochemical stability over 100 GCD cycles as compared to the Cu-ferrite electrode.

Efficient removal of noxious methylene blue and crystal violet dyes at neutral conditions by reusable montmorillonite/NiFe2O4@amine-functionalized chitosan composite

The jeopardy of the synthetic dyes effluents on human health and the environment has swiftly aggravated, threatening human survival. Hence, sustained studies have figured out the most acceptable way to eliminate this poisonous contaminant. Thereby, our investigation aimed to fabricate montmorillonite/magnetic NiFe₂O₄@amine-functionalized chitosan (MMT-mAmCs) composite as a promising green adsorbent to remove the cationic methylene blue (MB) and crystal violet (CV) dyes from the wastewater in neutral conditions. Interestingly, MMT-mAmCs composite carries high negative charges at a wide pH range from 4 to 11 as clarified from zeta potential measurements, asserting its suitability to adsorb the cationic contaminants. In addition, the experimental study confirmed that the optimum pH to adsorb both MB and CV was pH 7, inferring the ability of MMT-mAmCs to adsorb both cationic dyes in simple process conditions. Furthermore, the ferromagnetic behavior of the MMT-mAmCs composite is additional merit to our adsorbent that provides facile, fast, and flawless separation. Notably, the as-fabricated composite revealed an auspicious adsorbability towards the adsorptive removal of MB and CV, since the maximum adsorption capacity of MB and CV were 137 and 118 mg/g, respectively. Moreover, the isotherm and kinetic investigatins depicted that the adsorption of both cationic dyes fitted Langmuir and Pseudo 2nd order models, respectively. Besides, the advanced adsorbent preserved satisfactory adsorption characteristics with maximal removal efficacy exceeding 87% after reuse for ten consecutive cycles. More importantly, MMT-mAmCs efficiently adsorbed MB and CV from real agricultural water, Nile river water and wastewater samples at the neutral pH medium, reflecting its potentiality to be a superb reusable candidate for adsorptive removal cationic pollutants from their aquatic media.

Visible Light Induced Nano-Photocatalysis Trimetallic Cu0.5Zn0.5-Fe: Synthesis, Characterization and Application as Alcohols Oxidation Catalyst

Here, we report a visible light-induced-trimetallic catalyst (Cu0.5Zn0.5Fe2O4) prepared through green synthesis using Tilia plant extract. These nanomaterials were characterized for structural and morphological studies using powder x-ray diffraction (P-XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The spinel crystalline material was ~34 nm. In benign reaction conditions, the prepared photocatalyst oxidized various benzylic alcohols with excellent yield and selectivity toward aldehyde with 99% and 98%; respectively. Aromatic and aliphatic alcohols (such as furfuryl alcohol and 1-octanol) were photo-catalytically oxidized using Cu0.5Zn0.5Fe2O4, LED light, H2O2 as oxidant, 2 h reaction time and ambient temperature. The advantages of the catalyst were found in terms of reduced catalyst loading, activating catalyst using visible light in mild conditions, high conversion of the starting material and the recyclability up to 5 times without loss of the selectivity. Thus, our study offers a potential pathway for the photocatalytic nanomaterial, which will contribute to the advancement of photocatalysis studies.

An environment-friendly methodology for the construction of diversified bicycloacenaphtho[1,2-d]imidazole-8-thione scaffolds using spinel NiFe2O4 nanoparticles as a sustainable catalyst

Herein, we successfully developed an easy access to bicycloacenaphtho[1,2-d]imidazole-8-thione by one-pot three-component MCRs of acenaphthoquinone, aryl or alkyl isothiocyanates and amines using environmentally benevolent and recyclable spinel NiFe₂O₄ nanocatalyst in aqueous ethanol. A broad number of products have been synthesized with both EDGs and EWGs present in the ring which increases the diversity of the protocol. The NiFe₂O₄ nanopowder has been synthesized and thoroughly characterized by powdered XRD, HRTEM, EDX, BET and ICP-AES analysis. The protocol to this bicyclic-heterocycle is noteworthy due to good to excellent yields, practical simplicity and high regioselectivity without any troublesome or hazardous by-products and its easy recovery and reusability of the catalyst. Spinel NiFe₂O₄ NPs-catalysed synthesis of various bicycloacenaphtho[1,2-d]imidazole-8-thione scaffolds under mild and sustainable conditions.