Nanoporous titania-supported gold nanoparticles have been synthesized through the deposition–precipitation method, and the synthesized nanoparticles have been characterized by XRD, SEM, HRTEM, EDAX, BET adsorption isotherm, and IR and UV–vis spectral techniques. The efficiency of this catalyst toward green organic synthesis has been studied by carrying out the 1,3-dipolar cycloaddition of organic azides with a variety of terminal alkynes in water. The reaction proceeds regioselectively yielding the corresponding 1,4-disubstituted-1,2,3-triazole derivative in good to excellent yield.

The N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) derived silicate matrix supported core-shell TiO(2)-Au nanoparticles (EDAS/(TiO(2)-Au)(nps)) were prepared by NaBH(4) reduction of HAuCl(4) precursor on preformed TiO(2) nanoparticles in the presence of EDAS monomer. The core-shell (TiO(2)-Au)(nps) nanoparticles were stabilized by the amine functional group of the EDAS silicate sol-gel network. The potential application of this EDAS/(TiO(2)-Au)(nps) modified electrode toward the photoelectrochemical oxidation of methanol was explored. The EDAS/(TiO(2)-Au)(nps) modified electrode showed a 12-fold enhancement in the catalytic activity toward photoelectrooxidation of methanol when compared to TiO(2) dispersed in EDAS silicate sol-gel matrix. This improved photoelectrochemical performance is explained on the basis of beneficial promotion of interfacial charge transfer processes of the EDAS/(TiO(2)-Au)(nps) nanocomposite. A methanol oxidation peak current density of 12.3 mA cm(-2) was achieved at an optimum loading of Au(nps) on TiO(2) particles. This novel amine functionalized EDAS silicate sol-gel stabilized core-shell (TiO(2)-Au)(nps) nanomaterial could be an excellent candidate for the photocatalytic and photoelectrochemical applications.

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Objective: In the present system, the green synthesis of silver nanoparticles using marine the red alga Spyridia fusiformis and antibacterial activity was carried out. Methods:The seaweed extract was used for the synthesis of AgNPs Results:The UV-visible spectroscopy revealed surface plasmon resonance at 450 nm. The FT-IR measurements showed the possible functional groups responsible for the formation of nanoparticles. The X-ray diffraction analysis showed that the particles were crystalline in nature. TEM micrograph has shown the formation of silver nanoparticles with the size in the range of 5-50 nm. The silver nanoparticles synthesized from the S. fusiformis showed higher activity and proved their efficacy in controlling the pathogenic bacterial strains. The nanoparticles showed highest inhibition activity on K. pneumaniae and S. aureus up to 26 and 24±0.01 mm at 100 μg/ml of nanoparticles.at room temperature. The silver nanoparticles were characterized by using UVVisible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscope and X-ray diffraction (XRD) techniques. The antibacterial activity of biosynthesized silver nanoparticles was carried out by disc diffusion method against pathogenic bacteria. Conclusion:The synthesised AgNPs have shown the best antibacterial activity against human pathogens Keywords: Antibacterial activity, Green synthesis, Marine algae, Silver nanoparticles, Spyridia fusiformis E. coli, K. pneumoniae, S. aureus and P. aeruginosa. The above eco-friendly AgNPs synthesis procedure could be a viable solution for industrial applications in the future and therapeutic needs.