sodium-dodecyl-sulfate and stannic-oxide

Tin oxide (SnO2) nanoparticles of sizes ∼4.5, ∼10 and ∼30 nm were successfully synthesized by a simple chemical precipitation method using amino acid, glycine which acts as a complexing agent and surfactant, namely sodium dodecyl sulfate (SDS) as a stabilizing agent, at various calcination temperatures of 200, 400 and 600°C. This method resulted in the formation of spherical SnO2 nanoparticles and the size of the nanoparticles was found to be a factor of calcination temperature. The spherical SnO2 nanoparticles show a tetragonal rutile crystalline structure. A dramatic increase in band gap energy (3.8-4.21 eV) was observed with a decrease in grain size (30-4.5 nm) due to three dimensional quantum confinement effect shown by the synthesized SnO2 nanoparticles. SnO2 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and fourier transformed infrared spectroscopy (FT-IR). The optical properties were investigated using UV-visible spectroscopy. These SnO2 nanoparticles were employed as catalyst for the reduction of p-nitro phenol to p-amino phenol in aqueous medium for the first time. The synthesized SnO2 nanoparticles act as an efficient photocatalyst in the degradation of methyl violet 6B dye under direct sunlight. For the first time, methyl violet 6B dye was degraded by SnO2 nanoparticles under direct sunlight.

Topics: Aminophenols; Catalysis; Glycine; Green Chemistry Technology; Nanoparticles; Nitrophenols; Photolysis; Sodium Dodecyl Sulfate; Tin Compounds

The practical use of visible-light for bactericide treatment has been established by tin oxide nanostructures synthesized using a surfactant-assisted solvothermal method. Anionic (sodium n-dodecyl sulfate, SDS), cationic (cetyltrimethyl ammonium bromide, CTAB) and non-ionic (Tritron X-100) surfactants were used as morphology controlling agents. The as-synthesized nanoparticles are characterized by X-ray powder diffraction (XRD), UV-vis spectroscopy and scanning electron microscopy (SEM). The XRD patterns of the as-synthesized tin oxide nanoparticles were well indexed to the tetragonal rutile structure. Nanostructure tin oxide powders of about 70-92nm in size have been obtained with different morphologies. The spherical, cauliflower, flower petals morphologies of surfactant-mediated SnO2 were obtained using X-100, CTAB, and SDS, respectively and the spherical-like for surfactant-free SnO2 was observed in the SEM micrographs. The surfactant-mediated SnO2 samples showed absorption edges red shift to longer wavelength and increased absorption intensities compared to surfactant-free SnO2. Antibacterial effectiveness of SnO2 samples was tested against general Escherichia coli (E. coli ATCC 25922) under UV-, visible-light and dark conditions. The surfactant promoted antimicrobial effect under visible light by SnO2 band gap modification. In contrast, the surfactant-free SnO2 possessed higher photokilling activity under UV-light. The antibacterial performance of SnO2 samples as a function of their structural and morphological features such as particle size, surface area and visible/UV light absorbing capacity was discussed.

Topics: Anti-Bacterial Agents; Catalysis; Cetrimonium; Cetrimonium Compounds; Escherichia coli; Light; Metal Nanoparticles; Octoxynol; Sodium Dodecyl Sulfate; Surface-Active Agents; Tin Compounds