Removal of Pb(II) from Aqueous Solutions Using Magnetic Mesoporous Silica Nanocomposites: Modeling and Optimization Based on Response Surface Methodology

In the adsorption process of heavy metals, a major challenge is to design and develop adsorbent materials in an abundance of accessible adsorption sites with high affinity to achieve both fast adsorption kinetics and increased adsorption capacity for toxic contaminants. The removal of pollutants by mesoporous silica adsorbents is now in the limelight due to the nontoxicity and biocompatibility of these materials with the environment. In this study, a fibrous core-shell magnetic mesoporous composite (Fe3O4/SiO2/KCC-1) was successfully synthesized and used as a nano-adsorbent to remove Pb(II) from an aqueous solution. The adsorbent was characterized by employing TEM, SEM, FTIR, VSM, XRD, and N2 adsorption–desorption techniques. According to the results, Fe3O4/SiO2/KCC-1 was successfully synthesized with an average pore diameter of 7.94 nm, a surface area of 813.07 m2 g-1, and a pore volume of 1.41 cm3 g-1. The response surface methodology (RSM) was then adopted in the central composite design (CCD) to optimize parameters of the adsorption process. The optimal conditions for Pb(II) adsorption were then determined at a temperature of 80 °C, an adsorption dosage of 0.04 g L-1, a pH 5.6, and the contact time of 38 min. The removal rate of Pb(II) was 90%. Studies of equilibrium and kinetics indicated that the adsorption process followed Langmuir’s isotherm and the pseudo-first-order model with correlation coefficients of 0.98 and 0.99, respectively. The maximum adsorption capacity of Fe3O4/SiO2/KCC-1 was reported 574.4 mg g-1. Moreover, the thermodynamic parameters known as enthalpy (ΔH° = +5.84 kJ mol-1), negative Gibbs free energy (∆G°) values, and entropy (ΔS° = +23.42 kJ mol-1 K-1) indicated that the adsorption was endothermic and spontaneous with the increased disorder at the solid–liquid interphase

Synthesis of Ruthenium (II) trisbipyridine complex containing ionic liquids immobilized on fibrous CoMn2O4 for isolation of asphaltene from petroleum

The formation of a durable nanoadsorbent, known as DFCoMn2O4/IL@Ru(II), was achieved by binding a complex of Ru (II) trisbipyridine with ionic liquids (IL) to a dendritic fibrous CoMn2O4 (DFCoMn2O4). The resulting DFCoMn2O4/IL@Ru(II) was characterized using various techniques such as X-ray diffraction analysis (XRD), fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM). DFCoMn2O4/IL@Ru(II) was then employed as an environmentally friendly adsorbent for the removal and adsorption of asphaltene from petroleum. The presence of fibrous CoMn2O4 categories enhanced the adsorption capacity and facilitated the recovery of the adsorbent without significantly reducing the efficiency. The results demonstrated a clear synergistic effect between dendritic fibrous CoMn2O4 and the IL@Ru(II) categories, exhibiting a strong correlation. The utilization of the DFCoMn2O4/IL@Ru(II) system resulted in quasi-second-order adsorption kinetics. The experiment was conducted using the Taguchi method to minimize costs and time. Various amounts of asphaltene, temperatures, and adsorbent quantities were examined. Minitab software was deployed to evaluate the impact of these variables on asphaltene adsorption. The presence of ionic liquid groups enhanced the solubility of the heterogeneous adsorbent in environmentally friendly solvents, thereby enhancing function and reducing the time

Green synthesis and antibacterial effect of silver nanoparticles using Eucalyptus camaldulensis

Introduction and Aims: Due to the developing bacterial drug resistance to classical antimicrobial agents, it seems necessary to produce an innovative therapeutic approach to eliminate resistant pathogens. This study aimed to biosynthesis of silver nanoparticles (AgNPs) using flowers extract of Eucalyptus camaldulensis and determined of antibacterial activity of produced AgNPs.  Materials and Methods: We used an environmentally friendly extracellular biosynthetic technique for the production of the AgNPs. The reducing agents used to produce the nanoparticles were from the aqueous flowers extract of Eucalyptus camaldulensis. The AgNPs were characterized by color changes, the UV-visible spectroscopy, FTIR analysis, XRD patterns and Scanning Electron Microscopy (SEM) technique. The antibacterial activity of AgNPs was investigated against Gram-positive and Gram-negative bacteria ,through broth micro dilution (MIC values) and MBC (Minimum bactericidal concentration) assays. Results: An absorption peak at 413 nm and the color change to dark brown were corresponding to the plasmon absorbance of AgNPs and then were performed by FTIR and XRD methods. The average size of nanoparticles was observed between 67 and 80 nm. Furthermore, the MIC value of extract against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa were 3.12, 6.25, and 50 mg/mL, respectively. The corresponding MBC values were 6.25, 6.25 and 100 mg/mL, respectively. Conclusion: Our findings confirmed that extracellular synthesis of AgNPs mediated by E. camaldulensis flowers extract indicated a good bactericidal activity against the tested bacteria and can be used in various fields as an antibacterial agent. Further studies are needed to characterize the toxicity effect of these particles

Food Quality Monitoring Based on Hydrolysis-Induced Au-Catalyzed Heck Cross-Coupling by Ag Metallization

Visual detection of meat spoilage was performed based on hydrolysis-induced silver metallization on gold nanoparticles (Au NPs). The hydrolysis of 4-I-benzene-bounded Wang resin was induced by the release of a biogenic amine followed by Au-catalyzed Heck cross-coupling reaction that made silver-coated gold core-shell NPs (Au@Ag) in the presence of Ag ions (Ag metallization). A portable sensory cap was designed by this hypothesis and the successful results were obtained for histamine, trimethylamine, and a spoilage sheep meat. With this protocol, the localized surface plasmon resonance (LSPR) is tuned for absorption of Au NPs and leads to LSPR peak blue shift of gold nanoparticles due to the Ag metallization and the preparation of Au@Ag core-shell NPs. Au NPs and the resulting Au@Ag NPs were characterized by transmission electron microscopy (TEM), BET, ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and dynamic light scattering (DLS) analyses. Also, various control experiments were set up to credit the portable sensory tube

CO₂ transformation under mild conditions using tripolyphosphate-grafted KCC-1-NH₂

<p></p> <p>Fibrous nanosilica (KCC-1) as a catalyst support was investigated in terms of stability, recycling, and reusability. For the first time, CO₂ transformation was performed via the synthesis and application of KCC-1 together with sodium tripolyphosphate (STPP) and 3-aminopropyltriethoxysilane (APTES) as its functionalized derivative. To this goal, KCC-1/STPP NPs were applied to act as a nanocatalyst with excellent catalytic activities under green reaction conditions.</p

Photocatalysts under visible-UV light for removal of organic dyes using dendritic fibrous nano-titanium modified with DyVO4 nanoceramic

DyVO4 NPs in the nanospaces a fibre of dendritic fibrous nano-titanium together can lead to an unheard potent for the production of bifunctutional nanocatalyst (DFNT/DyVO4). Photocatalytic degradation of organic dyes residues is an environmentally friendly and promising approach for addressing challenges that threaten living organisms. In this study, an efficient fibrous heterojunction photocatalyst was rationally designed, fabricated, and successfully applied for removal of eosin, methyl orange, and methyl violet. The obtained results showed that the content of DyVO4 quantum dots affects the yield of degradation. Using quantum dots in the structure of the photocatalyst leads to an improvement in the capacity of light-harvesting, the efficiency of charge transfer, and the rate of electron transfer. The catalyst activity is evaluated considering different components of the catalyst for the synthesis of removal of organic dyes. The reasonable procedures were proposed according to the cooperation among the DFNT and DyVO4 groups NPs sites over the catalyst that can be recovered and then reused without any significant reactivity loss considering at least 10 consecutive turns

Application of green synthesized biogenic Nd2Zr2O7 supported on dendritic fibrous nano-titanium for photocatalytic and antibacterial activities

The combination of a phase junction and fibrous structure has been proven to improve the catalytic ability and performance, as well as the separation of nano titanium oxide. However, there is still a pressing need for facile and environmentally sustainable fabrication techniques. In this research, we introduce an innovative approach for the fabrication of dandelion-like TiO2 with anatase/TiO2 phase interfaces and an extremely specific exterior layer using a user-friendly and green deep eutectic solvent-tuning method. We have successfully synthesized DaNd2Zr2O7 nanospheres on dendritic fibrous nanotitanium (DFNT@DaNd2Zr2O7) using a straightforward method. The DFNT@DaNd2Zr2O7 composite retained its mesoporous structure and crystalline morphology, despite the loading of DaNd2Zr2O7. These nanocomposites are employed as active photocatalysts under UV radiation and can effectively treat water contaminated with organic pollutants and microorganisms. Additionally, they exhibit antimicrobial properties against gram-positive species like pathogenic strains of Enterococcus faecalis and Staphylococcus aureus, as well as Gram-negative species like Escherichia coli, Furthermore and Klebsiella pneumonia, these nanocomposites exhibit excellent stability over ten cycles, reinforcing their potential as proficient catalysts to address environmental concerns

Investigating the Cytotoxic Effect of Urolithin B and Cerium Oxide Nanoparticles Synthesized from Aloe Vera Plant on Brain Cancer Cell Colony (U87MG)

Background: Brain cancer is one of the types of cancer that appears with the growth of cancer cells in the brain. In this experimental study, we investigated and compared the effect of cerium oxide nanoparticles synthesized by the green method from Aloe vera with urolithin B on U87MG cancer cells. Materials and Methods: Cerium oxide nanoparticles were produced by the green synthesis method from the Aloe vera plant and confirmed by nanoparticle size characterization tests and an FESEM microscope. The U87MG cells were obtained from Pasteur Institute of Tehran, Iran, and after passage, they were treated with cerium oxide nanoparticles and urolithin B drug for 72 h and cell colonies for 15 days. Results: The IC50 of cancer cells in the MTT test for urolithin B and cerium oxide nanoparticles synthesized by green method from Aloe vera plant with urolithin B were 170 μM and 135 μM, respectively. In addition, the survival percentage results from the clonogenic test at a concentration of 30 μM for cerium oxide nanoparticles (78%), urolithin B(61%), and cerium oxide nanoparticles with urolithin B(30%), and for a concentration of 60 μM, it was 60, 42, and 16%, respectively. Conclusion: Urolithin B has a higher cytotoxic effect (170μM) than cerium oxide nanoparticles synthesized by the green method from the Aloe vera plant, and when combined with cerium oxide nanoparticles, this cytotoxic effect increased more (135μM). It also reduced the survival percentage of colonies within 15 days of treatment