Globally, water pollution is mainly caused by the presence of heavy metals and metalloids such as arsenic. The majority of the techniques employed in the removal are of low efficiency and high cost. Therefore, in this work it is presented the adsorption processes of arsenic (As III and V) ions employing magnetite nanoparticles (MNPs) synthesized by the aerosol assisted chemical vapor deposition (AACVD) process. The adsorption efficiency was determined at different times and concentrations. The remaining As concentration in the solutions was analyzed by atomic absorption spectroscopy. The adsorbed As ions on the surface of the NMPs was analyzed by high resolution transmission electron microscopy. The results showed an overall removal efficiency of 87% for As+3 and 98% for As+5, in a contact time of 15 minutes. Results suggested the use of NMPs as a promising alternative in the removal of As ions in water.

Abstract The optical band gap energy of ZnO nanorods was estimated by different methods found in literature. These nanorods were deposited onto TiO2 covered borosilicate glass substrates by aerosol assisted chemical vapor deposition. Characterization techniques were employed to reveal the crystalline structure, surface morphology and optical properties of the sample. The analysis proved that hexagonal cross-section ZnO nanorods in the wurtzite phase were grown onto a TiO2 buffer thin film of anatase. Variations in the components of transmittance and reflectance were associated with the development of a rough surface. Such fluctuations were correlated with the equations employed to estimate the optical band gap. The different methods indicated band gap values of 3.17 to 3.24 eV. The energy band gap of 3.24 eV agrees to that reported in the literature for ZnO nanorods. Fluorescence spectroscopy confirmed the accuracy of the mathematical predictions since an emission at 380 nm (3.26 eV) was seen.

In this work, we report the synthesis and microstructural characterization of Tin oxide thin films doped with fluorine for applications such as transparent conductive oxides. Tin oxide doped with fluorine thin films were deposited by aerosol assisted chemical vapor deposition technique onto a borosilicate glass substrate, using a precursor solution of stannic chloride in ethanol and ammonium fluoride as the dopant. Deposition temperature was varied between 623-773 K. Also, other deposition parameters such as concentration of the precursor solution and gas carrier flux were fixed at 0.1 mol∙dm-3 and 5 L min-1 respectively. Results indicate the presence of only the cassiterite phase of Tin oxide in all samples. Thin films obtained were characterized by X-Ray Diffraction. Surface morphology and microstructure were studied by field emission scanning electron microscopy, optical properties of samples were analyzed by total transmittance and reflectance spectra. The resistivity value of the films was measured by the sheet resistance.