Copper-doped TiO 2 nanoparticles were synthesised using an ultrasonic-assisted solÀgel method with various doping concentrations from 0 to 2.5 at.%. The samples were characterised by X-ray diffraction, UVÀvis diffuse reflectance spectroscopy (UVÀvis), transmission electron microscopy (TEM), BrunauerÀ EmmettÀTeller surface area determination, and zeta potential. The presence of copper in TiO 2 crystal structure was revealed by UVÀvis spectra, and the TEM analysis showed that particles are mainly spherical around the size range of 15À20 nm. In addition, doping copper into TiO 2 lattice caused a decrease in the surface area due to the aggregation of nanoparticles and a shift of isoelectric point towards lower pH when the dopant concentration increased. The photocatalytic reactivity of these materials was evaluated by the degradation of methylene blue and methyl orange under the UV light. The effect of the initial solution pH on the adsorption capacity and the photocatalytic behaviour of the Cu-doped TiO 2 in the decolourisation of these dyes were also studied.

This study presents a stable and controllable synthesis of the fluorescent magnetic nanoparticles in a flow-through microchannel. La Mer process is carried out to synthesize the magnetic nanoparticles using co-precipitation. Then, the magnetic nanoparticles are coated with conjugation of chitosan and fluorescent isothiocianate. The chemical composition of the magnetic nanoparticles and their sizes are determined. The magnetic property of saturation magnetization and coercive field is characterized. Also, the possibility of external manipulation by separating the synthesized fluorescent magnetic nanoparticles into non-reacting lamination flow is demonstrated. Finally, their fluorescence property is determined.