6 documents found, page 1 of 1
High performance of ionic-liquid-based materials to remove insecticides
Francisco, R.; Almeida, C.; Sousa, Ana Catarina A.; Neves, M.C.; Freire, M.G.Neonicotinoids are systemic insecticides commonly used for pest control in agriculture and veterinary applications. Due to their widespread use, neonicotinoid insecticides (neonics) are found in different environmental compartments, including water, soils, and biota, in which their high toxicity towards non-target organisms is a matter of great concern. Given their widespread use and high toxicity, the developm...
Supported Ionic Liquids materials to remove insecticides
Francisco, R.; Almeida, C.; Sousa, A. C. A.; Neves, M.C.; Freire, M. G.Neonicotinoids insecticides are generally used to control pests in agriculture and for veterinary applications.1,2 Due to their extensive use, these compounds can be found in various environmental compartments, such as water, soils, and biota, which can be a problem of concern due to their toxicity against non-target organisms.2 Given this, it is of utmost priority to develop innovative and effective strategies...
Photocatalytic decolorization of methylene blue in the presence of TiO2/ZnS nan...
Franco, A.; Neves, M.C.; Ribeiro Carrott, M.M.L.; Mendonça, M.H.; Pereira, M.I.; Monteiro, O.C.The synthesis of distinct nanocrystalline TiO2 capped ZnS sampleswas carried out using a chemical deposition method. The materials characterization showed that the presence of ZnS onto TiO2 surface results in a red shift of the material band edge when compared with the initial semiconductor. The photocatalytic activity of the prepared nanocomposites was tested on the decolorization of methylene blue (MB) aqueou...
Layer-by-layer deposition of organically capped quantum dots
Neves, M.C.; Pereira, A.S.; Peres, M.; Kholkin, A.; Monteiro, T.; Trindade, T.Cadmium chalcogenide quantum dots (QD's) were synthesised using a single source approach while zinc oxide QD's were obtained by a colloidal technique. In both situations the dots were surface capped with tri-octylphosphine oxide (TOPO) hence leading to nanodispersed systems in organic solvents such as toluene. The organically capped QD's (CdSe, CdS and ZnO) were used as building-units to fabricate LbL (layer-by...
Photoluminescence of zinc oxide supported on submicron silica particles
Neves, M.C.; Trindade, T.; Peres, M.; Wang, J.; Soares, M.J.; Neves, A.; Monteiro, T.Synthetic well-defined SiO2 particles were used as substrates to grow ZnS nanoparticles at the silica surfaces. Such SiO2/ZnS composite particles were investigated as precursors to produce ZnO supported on submicron silica, by a simple calcination process. The structural and optical properties of the supported ZnO phase are reported. The ZnO emission is dominated by the typical green band at 2.5 eV commonly ass...
Growth of cadmium selenide nanocrystals on submicron silica
Neves, M.C.; Soares, J.; Hempelmann, R.; Monteiro, T.; Trindade, T.Cadmium selenide nanocrystals were grown over silica surfaces using a one-step synthetic method involving the thermal degradation of the single-molecule precursor [Cd(Se2CNEt2)2], EtC2H5. The X-ray powder diffraction patterns for the SiO2/CdSe nanocomposites show diffraction peaks consistent with the presence of hexagonal-CdSe. Scanning and transmission electron microscopy show inorganic composite particles for...