Facile Preparation of Magnetic CuFe2O4 on Sepiolite/GO Nanocomposites for Efficient Removal of Pb(II) and Cd(II) from Aqueous Solution.

CuFe2O4 nanoparticles were synthesized and immobilized on sepiolite fibers and graphene oxide sheets, producing a CuFe2O4/sepiolite/GO (CFSG) nanocomposite via a facile single-pot method. The synthesized nanocomposite was characterized using TEM, FTIR, SEM-EDX, XRD, and TGA techniques to determine its composition, structure, and thermal stability. The adsorptive removal of Pb(II) and Cd(II) heavy metal ions from aqueous solutions was studied using the synthesized CFSG nanocomposite. Adsorption parameters such as CFSG loading, pH, contact time, and temperature were investigated. The CFGS nanocomposite showed a higher Pb(II) removal (qm = 238.1 mg/g) compared to Cd(II) (qm = 14.97 mg/g) in a Pb(II) and Cd(II) binary system. The Pb(II) and Cd(II) adsorption fitted well with the Langmuir model, followed by the pseudo-second-order model, and was found spontaneous. Adsorption thermodynamic analysis showed that the Pb(II) adsorption process was exothermic while Cd(II) adsorption was endothermic. The CuFe2O4 nanoparticles on the CFSG surface could facilitate the adsorption of heavy metal ions through electrostatic interaction and complexation processes.

Photoelectrochemical advanced oxidation processes for simultaneous removal of antibiotics and heavy metal ions in wastewater using 2D-on-2D WS2@CoFe2O4 heteronanostructures.

The presence of antibiotics in water poses significant threats to both human health and the environment. Addressing this issue requires the effective treatment of medical wastewater. Photoelectrochemical advanced oxidation processes (PEAOPs) are emerging as promising solutions for wastewater treatment. This process utilizes photocatalysts to convert charge carriers into reactive species such as hydroxyl radicals and superoxide ions, which are essential for degrading pollutants in wastewater. However, limitations in charge carrier separation and transport have hindered the efficiency of photoelectrochemical advanced oxidation processes. To overcome these limitations, we designed WS2@CoFe2O4 heterojunctions, optimizing their energy levels to enhance charge transport and separation. This improvement significantly increased the oxidation of antibiotics such as amoxicillin and azithromycin. Multiple reactions occurred at the WS2@CoFe2O4 heterojunctions during photoelectrochemical advanced oxidation processes, leading to the impressive degradation of up to 99% of antibiotics under visible light irradiation at 0.8 V. Urea and H2O2 acted as oxidation agents within photoelectrochemical advanced oxidation processes, amplifying the generation of hydroxyl radicals and superoxide ions, further enhancing antibiotic oxidation. Moreover, the WS2@CoFe2O4 photoanode efficiently oxidized toxic antibiotics while converting As(III) into the less harmful As(V). Crucially, recyclability tests confirmed the robustness of the WS2@CoFe2O4 photoanode, ensuring its suitability for prolonged use in photoelectrochemical advanced oxidation processes. Integrating WS2@CoFe2O4 photoanodes into water purification systems can enhance efficiency, reduce energy consumption, and improve economic viability. This technology's scalability and its ability to protect ecosystems while conserving water resources make it a promising solution for addressing the critical issue of antibiotic pollution in water environments.

An advanced photo-oxidation process for pharmaceuticals using plasmon-assisted Ag-CoFe2O4 photocatalysts.

The discharge of amoxicillin (AMX) from pharmaceutical intermediates has adverse effects on aquatic ecosystems. The elimination of AMX requires advanced oxidation processes (AOPs) that utilize high-performance photocatalysts. Furthermore, the design of highly visible light photocatalysts for AOPs demands both cost-effectiveness and efficiency. In this work, a plasmon-assisted visible light photocatalyst of 2D Ag-CoFe2O4 nanohybrids was successfully synthesized and characterized with several analytical tools to degrade AMX in aqueous solutions through advanced AOPs. The results showed that the Ag-CoFe2O4 nanohybrids had excellent photocatalytic activity and stability, which could efficiently reduce the AMX concentration by 99% within 70 min under visible light irradiation. In particular, CoFe2O4 and Ag have an interfacial contact that prevents electron-hole pair recombination more effectively than pure CoFe2O4, which results in electrons in its conduction band (CB) migrating to metallic Ag sites. Thus, charge transfers between the two materials are more efficient, leading to higher photocatalytic oxidation of AMX. Furthermore, the surface plasmon of Ag nanoparticles are excited by their plasmonic resonance, which increases the absorption of visible light. The plasmon-assisted visible light photocatalyst could replace expensive and energy-intensive advanced oxidation processes (AOPs). AOPs pathways associated with AMX have been discussed in detail. The HPLC chromatogram clearly showed AMX was oxidized by four-membered B-lactam ring opening and hydroxylation with •OH. 2D Ag-CoFe2O4 heterostructure was found to be efficient, selective, and cost-effective for the degradation of several pharmaceutical compounds. Additionally, it was found to be eco-friendly and sustainable, making it a viable alternative to AOPs.

Phosphorus-modified copper ferrite (P-CuFe2O4) nanoparticles for photocatalytic ozonation of lomefloxacin.

Phosphorus-modified copper ferrite (P-CuFe2O4) nanoparticles were prepared by a simple sol-gel auto-combustion process and used for the photocatalytic ozonation of lomefloxacin (LOM). The morphology, crystallinity, and structure of the synthesized CuFe2O4 and P-CuFe2O4 nanoparticles were investigated using various techniques. The high-performance liquid chromatography (HPLC) analysis revealed that the degradation of LOM achieved a 99% reduction after a duration of 90 min in the photocatalytic ozonation system. In accordance with the charge-to-mass ratio, four intermediates were proposed with the help of their fragments obtained in LC-MS/MS. The degradation kinetics of lomefloxacin followed a pseudo-first order reaction, and the degradation mechanism was proposed based on the results. P0.035Cu0.965Fe2O4 showed the highest total organic carbon (TOC) removal with 20.15% in 90 min, highest specific surface area and the highest fluoride and ammonium production using the ion chromatography (IC). The experimental results obtained from the electron paramagnetic resonance (EPR) analysis indicated that the modified P-CuFe2O4 samples exhibited significantly elevated levels of superoxide (.O2-) production compared to the CuFe2O4 samples. The findings of this study demonstrate that the introduction of phosphorus modification into the copper ferrite photocatalyst led to an augmentation of both the specific surface area and the total pore volume. Furthermore, the incorporation of phosphorus served to promote the efficient separation of electron-hole pairs by effectively trapping electrons in the conduction band, hence enhancing the degradation efficiency.

Effective removal of azithromycin by novel g-C3N4/CdS/CuFe2O4 nanocomposite under visible light irradiation.

In this study, the visible light active pristine, binary and ternary g-C3N4/CdS/CuFe2O4 nanocomposite is prepared through a coprecipitation-assisted hydrothermal technique. The characterization of the as-synthesized catalysts was conducted using various analytical techniques. When compared with pristine and binary nanocomposites, the ternary g-C3N4/CdS/CuFe2O4 nanocomposite exhibits higher photocatalytic degradation of azithromycin (AZ) under a visible light source. Ternary nanocomposite exhibits high AZ removal efficiency of about 85% within 90 min of the photocatalytic degradation experiment. Enhanced the visible light absorption ability and the suppression of photoexcited charge carriers is also achieved by forming heterojunctions between pristine materials. The ternary nanocomposite exhibited ∼2 times higher degradation efficiency than CdS/CuFe2O4 nanoparticles and ∼3 times higher degradation efficiency than CuFe2O4. The trapping experiments were conducted and it shows superoxide radicals (O2•-) are the predominant reactive species involved in the photocatalytic degradation reaction. This study provided a promising approach for the treatment of contaminated water using g-C3N4/CdS/CuFe2O4 as a photocatalyst.

PS9, Derived from an Aquatic Fungus Virulent Protein, Glycosyl Hydrolase, Arrests MCF-7 Proliferation by Regulating Intracellular Reactive Oxygen Species and Apoptotic Pathways.

One of the most common diseases in women is breast cancer, which has the highest death globally. Surgery, chemotherapy, hormone treatments, and radiation are the current treatment options for breast cancer. However, these options have several adverse side effects. Recently, peptide-based drugs have gained attention as anticancer therapy. Studies report that peptides from biological toxins such as venom and virulent pathogenic molecules have potential therapeutic effects against multiple diseases, including cancers. This study reports on the in vitro anticancer effect of a short peptide, PS9, derived from a virulent protein, glycosyl hydrolase, of an aquatic fungus, Aphanomyces invadans. This peptide arrests MCF-7 proliferation by regulating intercellular reactive oxygen species (ROS) and apoptotic pathways. Based on the potential for the anticancer effect of PS9, from the in silico analysis, in vitro analyses using MCF-7 cells were executed. PS9 showed a dose-dependent activity; its IC50 value was 25.27-43.28 µM at 24 h. The acridine orange/ethidium bromide (AO/EtBr) staining, to establish the status of apoptosis in MCF-7 cells, showed morphologies for early and late apoptosis and necrotic cell death. The 2,7-dichlorodihydrofluorescein diacetate (DCFDA) staining and biochemical analyses showed a significant increase in reactive oxygen species (ROS). Besides, PS9 has been shown to regulate the caspase-mediated apoptotic pathway. PS9 is nontoxic, in vitro, and in vivo zebrafish larvae. Together, PS9 may have an anticancer effect in vitro.

A Review of Advanced Multifunctional Magnetic Nanostructures for Cancer Diagnosis and Therapy Integrated into an Artificial Intelligence Approach.

The new era of nanomedicine offers significant opportunities for cancer diagnostics and treatment. Magnetic nanoplatforms could be highly effective tools for cancer diagnosis and treatment in the future. Due to their tunable morphologies and superior properties, multifunctional magnetic nanomaterials and their hybrid nanostructures can be designed as specific carriers of drugs, imaging agents, and magnetic theranostics. Multifunctional magnetic nanostructures are promising theranostic agents due to their ability to diagnose and combine therapies. This review provides a comprehensive overview of the development of advanced multifunctional magnetic nanostructures combining magnetic and optical properties, providing photoresponsive magnetic platforms for promising medical applications. Moreover, this review discusses various innovative developments using multifunctional magnetic nanostructures, including drug delivery, cancer treatment, tumor-specific ligands that deliver chemotherapeutics or hormonal agents, magnetic resonance imaging, and tissue engineering. Additionally, artificial intelligence (AI) can be used to optimize material properties in cancer diagnosis and treatment, based on predicted interactions with drugs, cell membranes, vasculature, biological fluid, and the immune system to enhance the effectiveness of therapeutic agents. Furthermore, this review provides an overview of AI approaches used to assess the practical utility of multifunctional magnetic nanostructures for cancer diagnosis and treatment. Finally, the review presents the current knowledge and perspectives on hybrid magnetic systems as cancer treatment tools with AI models.

Incorporation of α-MnO2 Nanoflowers into Zinc-Terephthalate Metal-Organic Frameworks for High-Performance Asymmetric Supercapacitors.

Herein, we report the synthesis of α-MnO2 nanoflower-incorporated zinc-terephthalate MOFs (MnO2@Zn-MOFs) via the conventional solution phase synthesis technique as an electrode material for supercapacitor applications. The material was characterized by powder-X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques. The prepared electrode material exhibited a specific capacitance of 880.58 F g-1 at 5 A g-1, which is higher than the pure Zn-BDC (610.83 F g-1) and pure α-MnO2 (541.69 F g-1). Also, it showed a 94% capacitance retention of its initial value after 10,000 cycles at 10 A g-1. The improved performance is attributed to the increased number of reactive sites and improved redox activity due to MnO2 inclusion. Moreover, an asymmetric supercapacitor assembled using MnO2@Zn-MOF as the anode and carbon black as the cathode delivered a specific capacitance of 160 F g-1 at 3 A g-1 with a high energy density of 40.68 W h kg-1 at a power density of 20.24 kW kg-1 with an operating potential of 0-1.35 V. The ASC also exhibited a good cycle stability of 90% of its initial capacitance.

Controlled Synthesis of Dendrite-like Polyglycerols Using Aluminum Complex for Biomedical Applications.

This work describes a one-pot synthesis of dendrite-like hyperbranched polyglycerols (HPGs) via a ring-opening multibranching polymerization (ROMBP) process using a bis(5,7-dichloro-2-methyl-8-quinolinolato)methyl aluminum complex (1) as a catalyst and 1,1,1-tris(hydroxymethyl)propane/trimethylol propane (TMP) as an initiator. Single-crystal X-ray diffraction (XRD) analysis was used to elucidate the molecular structure of complex 1. Inverse-gated (IG)13C NMR analysis of HPGs showed degree of branching between 0.50 and 0.57. Gel permeation chromatography (GPC) analysis of the HPG polymers provided low, medium, and high-molecular weight (M n) polymers ranging from 14 to 73 kDa and molecular weight distributions (M w/M n) between 1.16 and 1.35. The obtained HPGs exhibited high wettability with water contact angle between 18 and 21° and T g ranging between -39 and -55 °C. Notably, ancillary ligand-supported aluminum complexes as catalysts for HPG polymerization reactions have not been reported to date. The obtained HPG polymers in the presence of the aluminum complex (1) can be used for various biomedical applications. Here, nanocomposite electrospun fibers were fabricated with synthesized HPG polymer. The nanofibers were subjected to cell culture experiments to evaluate cytocompatibility behavior with L929 and MG63 cells. The cytocompatibility studies of HPG polymer and nanocomposite scaffold showed high cell viability and spreading. The study results concluded, synthesized HPG polymers and composite nanofibers can be used for various biomedical applications.

Colloidal gas aphrons for biotechnology applications: a mini review.

Colloidal gas aphrons (CGAs) are highly stable, spherical, micrometer-sized bubbles encapsulated by surfactant multilayers. They have several intriguing properties, including: high stability, large interfacial area, and the ability to maintain the same charge as their parent molecules. The physical properties of CGAs make them ideal for biotechnological applications such as the recovery of a variety of: biomolecules, particularly proteins, yeast, enzymes, and microalgae. In this review, the bio-application of CGAs for the recovery of natural components is presented, as well as: experimental results, technical challenges, and critical research directions for the future. Experimental results from the literature showed that the recovery of biomolecules was mainly determined by electrostatic or hydrophobic interactions between polyphenols and proteins (lysozyme, ß-casein, ß-lactoglobulin, etc.), yeast, biological molecules (gallic acid and norbixin), and microalgae with CGAs. Knowledge transfer is essential for commercializing CGA-based bio-product recovery, which will be recognized as a viable technology in the future.

Synthesis and characterization of SnO2/rGO nanocomposite for an efficient photocatalytic degradation of pharmaceutical pollutant: Kinetics, mechanism and recyclability.

The SnO2 and SnO2/rGO nanostructures were successfully synthesized using the facile hydrothermal synthesis technique. The prepared nanostructures were well studied using different techniques such as XRD, XPS, UV-DRS, FT-IR, EDX, SEM and HR-TEM analysis. The crystalline nature of SnO2 and SnO2/rGO was confirmed by the XRD technique. The formation of highly pure SnO2 and SnO2/rGO nanostructures was confirmed by EDX analysis. The morphological results show the good agglomeration of several spherical nanoparticles. The optical properties were studied through the UV-DRS technique and the bandgap energies of SnO2 and SnO2/rGO are estimated to be 3.12 eV and 2.71 eV, respectively. The photocatalytic degradation percentage in presence of SnO2 and SnO2/rGO against RhB was found to be 96% and 98%, respectively. The degradation of TTC molecules was estimated as 90% and 88% with SnO2/rGO and SnO2, respectively. The degradation of both RhB and TTC molecules was well suited with the pseudo-first-order kinetics. The results of successive experiments clearly show the enhancement in the photocatalytic properties in the SnO2/rGO nanostructures.

Synthesis and Characterization of Ternary α-Fe2O3/NiO/rGO Composite for High-Performance Supercapacitors.

Herein, pure α-Fe2O3, binary α-Fe2O3/NiO, and ternary α-Fe2O3/NiO/rGO composites were prepared by a hydrothermal method. The properties of the prepared materials were studied by powder X-ray diffraction, scanning electron microscopy, TEM, XPS, and Brunauer-Emmett-Teller techniques. The clusters of smaller α-Fe2O3 nanoparticles (∼30 nm) along with conducting NiO was freely covered by the rGO layer sheet, which offer a higher electrode-electrolyte interface for improved electrochemical performance. The ternary composite has shown a higher specific capacitance of 747 F g-1@ a current density of 1 A g-1 in a 6 M KOH solution, when compared with that of α-Fe2O3/rGO (610 F g-1@1 A g-1) and α-Fe2O3 (440 F g-1@1 A g-1) and the nanocomposite. Moreover, the ternary α-Fe2O3/NiO/rGO composite exhibited a 98% rate capability @ 10 A g-1. The exceptional electrochemical performance of ternary composites has been recognized as a result of their well-designed unique architecture, which provides a large surface area and synergistic effects among all three constituents. The asymmetric supercapacitor (ASC) device was assembled using the ternary α-Fe2O3/NiO/rGO composite as the anode electrode (positive) material and activated carbon as the cathode (negative) material. The ASC device has an energy density of 35.38 W h kg-1 at a power density of 558.6 W kg-1 and retains a 94.52% capacitance after 5000 cycles at a 1 A g-1 current density.

Adsorptive removal of Acid Blue 113 using hydroxyapatite nanoadsorbents synthesized using Peltophorum pterocarpum pod extract.

The present work reports the study on the green synthesis of hydroxyapatite (HAP) nanoadsorbents using Peltophorum pterocarpum pod extract. HAP nanoadsorbents were characterized by using FESEM, EDS, TEM, XRD, FTIR, XPS, and BET analyses. The results highlighted the high purity, needle-like aggregations, and crystalline nature of the prepared HAP nanoadsorbents. The surface area was determined as 40.04 m2/g possessing mesopores that can be related to the high adsorption efficiency of the HAP for the removal of a toxic dye, - Acid Blue 113 (AB 113) from water. Central Composite Design (CCD) was used for optimizing the adsorption process, which yielded 94.59% removal efficiency at the optimum conditions (dose: 0.5 g/L, AB 113 dye concentration: 25 ppm, agitation speed: 173 rpm, and adsorption time: 120 min). The adsorption kinetics followed the pseudo-second-order model (R2:0.9996) and the equilibrium data fitted well with the Freundlich isotherm (R2:0.9924). The thermodynamic parameters indicated that the adsorption of AB 113 was a spontaneous and exothermic process. The highest adsorption capacity was determined as 153.85 mg/g, which suggested the promising role of green HAP nanoadsorbents in environmental remediation applications.

White LED active α-Fe2O3/rGO photocatalytic nanocomposite for an effective degradation of tetracycline and ibuprofen molecules.

The formation of phase pure magnetically separable α-Fe2O3 and α-Fe2O3/rGO nanostructures were achieved through a simple hydrothermal technique. The properties of synthesized materials were investigated through different analytical techniques. The formation of phase pure FO and FO/rGO nanostructures were confirmed by XRD analysis with crystallite size of about ∼42 nm and ∼65 nm, respectively. The morphological analysis reveals the formation of sphere-like nanoparticles with high agglomeration. The UV-DRS analysis clearly shows the enhanced visible-light activity of FO/rGO nanoparticles. The BET analysis revealed the mesoporous property of FO/rGO nanocomposite. The enhancement in the photoinduced charge transfer process is observed after including rGO nanoparticles with FO. The photocatalytic efficiency of nanomaterials was analyzed using tetracycline and ibuprofen as model organic pollutants under white LED irradiation. The enhanced photocatalytic degradation ability of FO/rGO nanocomposite is studied against both tetracycline and ibuprofen molecules.

Fabrication of Ru-CoFe2O4/RGO hierarchical nanostructures for high-performance photoelectrodes to reduce hazards Cr(VI) into Cr(III) coupled with anodic oxidation of phenols.

Dual-functional photo (electro)catalysis (PEC) is a key strategy for removing coexisting heavy metals and phenolic compounds from wastewater treatment systems. To design a PEC cell, it is crucial to use chemically stable and cost-effective bifunctional photocatalysts. The present study shows that ruthenium metallic nanoparticles decorated with CoFe2O4/RGO (Ru-CoFe2O4/RGO) are effective bifunctional photoelectrodes for the reduction of Cr(VI) ions. Ru-CoFe2O4/RGO achieves a maximum Cr(VI) reduction rate of 99% at 30 min under visible light irradiation, which is much higher than previously reported catalysts. Moreover, PEC Cr(VI) reduction rate is also tuned by adding varying concentration of phenol. A mechanism for the concurrent removal of Cr(VI) and phenol has been revealed over a bifunctional Ru-CoFe2O4/RGO catalyst. A number of key conclusions emerged from this study, demonstrating the dual role of phenol during Cr(VI) reduction by PEC. Anodic oxidation of phenol produces the enormous H+ ion, which appears to be a key component of Cr(VI) reduction. Additionally, phenolic molecules serve as hole (h+) scavengers that reduce e-/h+ recombination, thus enhancing the reduction rate of Cr(VI). Therefore, the Ru-CoFe2O4/RGO photoelectrode exhibits a promising capability of reducing both heavy metals and phenolic compounds simultaneously in wastewater.

Solvent-Influenced Fragmentations in Free-Standing Three-Dimensional Covalent Organic Framework Membranes for Hydrophobicity Switching.

The ordered open organic frameworks membranes are attractive candidates for flow-assisted molecular separations. The physicochemical properties of such membranes mostly depend on their selectively chosen functional building blocks. In this work, we have introduced a novel concept of functional switchability of three-dimensional covalent organic framework (3D-COF) membranes through a simple solvent-influenced fragmentation method. This room-temperature interfacial synthesis provides free-standing 3D-COF membranes with distinct physicochemical properties from the same building monomers. Notably, the change of solvent from chloroform to ethyl acetate switches the membrane property from hydrophilic (water contact angle 60°) to hydrophobic (water contact angle 142°) nature. The hydrophobic 3D-COF membrane selectively passes oil molecules from an oil-water emulsion with a gravitational flux of 1536 L m-2 h-1 .

Non-enzymatic electrochemical dopamine sensing probe based on hexagonal shape zinc-doped cobalt oxide (Zn-Co2O4) nanostructure.

A non-enzymatic dopamine electrochemical sensing probe was developed. A hexagonal shape zinc-doped cobalt oxide (Zn-Co2O4) nanostructure was prepared by a facile hydrothermal approach. The combination of Zn, which has an abundance of electrons, and Co3O4 exhibited a synergistically electron-rich nanocomposite. The crystallinity of the nanostructure was investigated using X-ray diffraction. A scanning electron microscope (SEM) was used to examine the surface morphology, revealing hexagonal nanoparticles with an average particle size of 400 nm. High-resolution transmission electron microscopy (HR-TEM) was used to confirm the nanostructure of the doped material. The nanostructure's bonding and functional groups were verified using Fourier transform infrared spectroscopy (FTIR). The electrochemical characterization was conducted by using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and amperometry. The resistivity of the electrode was confirmed through EIS and showed that the bare glassy carbon electrode (GCE) exhibited higher charge transfer resistance as compared to modified Zn-Co2O4/GCE. The sensing probe was developed by modifying the surface of GCE with Zn-Co2O4 nanostructure and tested as an electrochemical sensor for dopamine oxidation; it operated best at a working potential of 0.17 V (vs Ag/AgCl). The developed sensor exhibited a low limit of detection (0.002 µM), a high sensitivity (126 µA. µM-1 cm-2), and a wide linear range (0.2 to 185 µM). The sensor showed a short response time of < 1 s. The sensor's selectivity was investigated in the presence of coexisting species (uric acid, ascorbic acid, adrenaline, epinephrine, norepinephrine, histamine, serotonin, tyramine, phenethylamine, and glucose) with no effects on dopamine determination results. The developed sensor was also successfully used for determining dopamine concentrations in a real sample.

Sulfide remediation from wastewater using hydrothermally synthesized δ-MnO2/porous graphitic carbon as adsorbent.

A facile hydrothermal assisted in-situ precipitation technique was employed for synthesizing highly efficient porous graphitic carbon/manganese dioxide (PGC/MnO2) nanocomposite adsorbent using calcium alginate as carbon precursor. Morphological and structural characterization using scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction techniques confirmed the interconnected nanoporous architecture and birnessite (δ) MnO2 polymorph evenly distributed on the PGC structure. The synergistic effect of PGC and MnO2 was exploited for enhanced sulfide removal from wastewater via adsorptive oxidation. The effect of different experimental parameters, including solution pH, initial sulfide concentration, adsorbent dosage, and contact time on removal efficiency was investigated. The equilibrium and kinetic data for sulfide adsorption by PGC/MnO2 nanocomposite fitted well with Langmuir isotherm and pseudo-second-order kinetic model, respectively. The maximum uptake capacity of sulfide by the nanocomposite was determined as 500 mg/g with complete sulfide removal. Further, it was estimated that a typical field application using the synthesized nanocomposite adsorbent would require 0.5-1 g/L per 200 mg/L of sulfide contaminated wastewater. Based on the experimental results, a schematic of the adsorptive oxidation mechanism of PGC/MnO2 nanocomposite is proposed.

A facile approach for the synthesis of porous hematite and magnetite nanoparticles through sol-gel self-combustion.

Porous magnetite (Fe3O4) and hematite (α-Fe2O3) nanoparticles were prepared via the sol-gel auto-combustion method. The gels were prepared by reacting ferric nitrates (as oxidants) with starch (as fuel) at an elevated temperature of 200 °C. Different ratios (Φ) of ferric nitrates to starch were used for the synthesis (Φ = fuel/oxidant). The synthesized iron oxides were characterized by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET) and vibrating sample magnetometer (VSM) analysis techniques. The crystal structure, morphology, and specific surface area of the iron oxide nanoparticles (Fe3O4 and α-Fe2O3) were found to be dependent on the starch content. The FT-IR, XRD and VSM analysis of the iron oxides for Φ = 0.3 and 0.7 confirmed the formation of the α-Fe2O3 core, whereas at Φ = 1, 1.7, and 2 showed that Fe3O4 cores were formed with the highest saturation magnetization of 60.36 emu/g at Φ = 1. The morphology of the Fe3O4 nanoparticles exhibited a quasi-spherical shape, while α-Fe2O3 nanoparticles appeared polygonal and formed clusters. The highest specific surface area was found to be 48 m2 g-1 for Φ = 1.7 owing to the rapid thermal decomposition process. Type II and type III isotherms indicated mesoporous structures.

Green Synthesis, Characterization, Antimicrobial, Anti-Cancer, and Optimization of Colorimetric Sensing of Hydrogen Peroxide of Algae Extract Capped Silver Nanoparticles.

A green and cost-effective technique for the preparation of silver nanoparticles (Algae-AgNPs) as a colorimetric sensor for hydrogen peroxide (H2O2) is described. Silver nanoparticles were capped using the green algae (Noctiluca scintillans) extract at an optimum time of 3 h at 80 °C. The pH of the plant extract (pH = 7.0) yields nanoparticles with a mean size of 4.13 nm and a zeta potential of 0.200 ± 0.02 mV and negative polarity, using dynamic light scattering (DLS). High-resolution transmission electron microscopy (HRTEM) analysis showed regular spherical particles with the average size of 4.5 nm. Selected area electron diffraction (SAED) results revealed the polycrystalline nature of the silver nanoparticles. The obtained patterns were indexed as (111), (200), (220), and (311) reflections of the fcc (face centered cubic) silver crystal based on their d-spacing of 2.47, 2.13, 1.49, and 1.27 Å, respectively. The apparent color change from brown to colorless was observed when nanoparticles reacted with H2O2. Linear responses were obtained in three different ranges (nM, µM, and mM). Limits of detection (LOD) of 1.33 ± 0.02 and 1.77 ± 0.02 nM and quantitation limits (LOQ) of 7.31 ± 0.03 and 9.67 ± 0.03 nM were obtained for Abs and ΔAbs calibration curves, respectively. 10% v/v Algae-AgNPs solution inhibited Staphylococcus aureus over Escherichia coli, while a 50% reduction of tumor cell growth of MDA-MB-231 human breast adenocarcinoma was obtained.