ABSTRACT
Scientists are interested in biosynthesis of gold nanoparticles owing to their catalytic and biological features. In this research, the extract of Convolvulus fruticosus (C. fruticosus; CFE) extract was applied to synthesize spherical-like gold nanoparticles (CFE@AuNPs). As-prepared CFE@AuNPs was characterized by TEM, FE-SEM, XRD, FT-IR, EDS, UV-Vis and DLS analysis. Identification analysis revealed that the properties of as-prepared CFE@AuNPs with spherical morphology were homogeneous, regular, high dispersibility and low agglomeration. The particle size of biogenic gold nanoparticles (about 35 nm) was obtained using FE-SEM, TEM and DLS techniques. Photocatalytic experiment of CFE@AuNPs determined by degradation of basic violet 10 (BV10), basic blue 9 (BB9) and acid red 51 (AR51) pollutants with percent degradation of 94.3%, 90.2%, 85.4% under UV and 80.6%, 79.8%, 73.3% under visible light irradiation, respectively. As well as, as-prepared CFE@AuNPs illustrated as a significant inhibitory influence against ATCC strain for both gram-positive and gram-negative bacteria. Owing to the antibacterial results, CFE@AuNPs enhanced antibacterial activity against E. coli, A. baumannii, P. aeruginosa, S. aureus, K. pneumonia, P. mirabilis and E. faecalis with MIC of 0.075, 0.075, 0.075, 0.075, 0.15, 0.075 and 0.037 mg/ml, respectively. All in all, results of the findings showed that C. fruticosus capped gold nanoparticles can find applications in the various arena including biological and removal of toxic pollutants for water purification.
Subject(s)
Anti-Bacterial Agents/pharmacology , Convolvulus/chemistry , Gold/chemistry , Metal Nanoparticles/chemistry , Plant Extracts/pharmacology , Catalysis , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Spectrum Analysis/methods , Temperature , X-Ray DiffractionABSTRACT
In this work we have demonstrated a facile formation of CuO nanostructures on copper substrates by the oxidation of copper foil in ethylene glycol (EG) at 80 °C. On immersing a prepared CuO film into a solution containing 0.1 g Zn(acac)2 in 20 mL EG for 8 h, ZnO flower-like microstructures composed of hierarchical three-dimensional (3D) aggregated nanoparticles and spherical architectures were spontaneously formed at 100 °C. The as-synthesized thin films and 3D microstructures were characterized using XRD, SEM, and EDS techniques. The effects of sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB), and polyethylene glycol (PEG) 6000 as surfactants and stabilizers on the morphology of the CuO and ZnO structures were discussed. Possible growth mechanisms for the controlled organization of primary building units into CuO nanostructures and 3D flower-like ZnO architectures were proposed. The hydrophobic property of the products was characterized by means of water contact angle measurement. After simple surface modification with stearic acid and PDMS, the resulting films showed hydrophobic and even superhydrophobic characteristics due to their special surface energy and nano-microstructure morphology. Importantly, stable superhydrophobicity with a contact angle of 153.5° was successfully observed for CuO-ZnO microflowers after modification with PDMS. The electrochemical impedance measurements proved that the anticorrosion efficiency for the CuO/ZnO/PDMS sample was about 99%.
ABSTRACT
In this study, at first, TiO2 nanowire was prepared by an alkaline hydrothermal process. In the following, Gr/Pd/TiO2-NPs and Gr/Pd/TiO2-NWs were synthesized by a combination of hydrothermal and photodeposition methods. The properties of as prepared products were characterized using XRD, FT-IR, SEM, DRS, TEM, ICP-OES, EDS and TGA analysis. SEM results confirmed nanodimension structure for all samples. Also the band gap values obtained using DRS technique suggests that all the samples have semiconductor behavior. Using TGA analysis, the amount of graphene loaded onto the powders was confirmed. Photocatalytic degradation of rhodamine B by TiO2-NWs, Gr/Pd/TiO2-NPs and Gr/Pd/TiO2-NWs nanocomposites was compared under ultraviolet light irradiation. Results confirmed that the Gr/Pd/TiO2-NWs composite show the highest photocatalytic activity due to much higher available surface area of TiO2 substrate in nanowire structure. It is expected that the synthesis of the high surface area TiO2 nanowires, facile photodeposition of palladium into its texture, and simple conversion of GO to graphene during hydrothermal process without using strong reducing agents, could be a suitable rote for preparing different types of carbon based TiO2 nanocomposite photocatalysts.
ABSTRACT
A simple and low-cost route to fabricate durable superhydrophobic magnetic polyurethane sponge was obtained by immersing a polyurethane sponge in a colloidal suspension of straw soot and magnetic nanoparticles. The as prepared sponge was used for separation of oil/water mixture. XRD, FT-IR, VSM, SEM and contact angle measurement analysis were used for characterization the materials. The effects of different stabilizer or surfactants (cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyethylene glycol 6000 (PEG 6000)) on the morphology and geometrical structure of magnetic nanoparticles were investigated. For increasing the hydrophobic property of the surface, the sponge was further modified using PDMS. Results indicated that this matter can promote interfacial interactions between the sponge surface and oil. The prepared sponge showed excellent superhydrophobicity with water contact angle as high as 154°. Experiments showed that the amount of the absorbed oil was about 30 times of sponges own weight, it has our 30 times recyclability and the advantage of magnetic separation.
