Photocatalytic and optical properties of vanadium doped zinc oxide nanoparticles

Vanadium-doped zinc oxide nanoparticles have been synthesized by sol-gel method using a supercritical drying in ethyl alcohol at 250°C.after heating under natural atmosphere at 500 °C for 2 hours, the obtained nanopowder was characterized by various techniques such as particle size analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and photoluminescence (PL). In the as-prepared state, the powder with an average particle size of 25 nm presents a strong luminescence band in the visible range. From photoluminescence excitation (PLE) the energy position of the obtained PL band depends on the wavelength excitation and this PL can be obtained by some visible excitations. This result is very promising for visible photocatalysis applications; which was confirmed by methylene blue photodegradation using visible lamp as light source. By comparison with undoped ZnO results, elaborated in the same conditions, we can conclude that the vanadium is responsible to this visible photocatalytic activation.