Microemulsion synthesis, optical and photocatalytic properties of vanadium‐doped nano ZnO

Abstract

In the present work, vanadium-doped ZnO nanoparticles with different V concentrations were prepared via microemulsion method and employed as an effective photocatalyst for the degradation of methylene blue. The prepared samples were characterized by different techniques such as thermogravimetric and differential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental mapping (MAP), and ultraviolet-visible spectroscopy (Uv-Vis). The XRD patterns of vanadium-doped samples were assigned to wurtzite structure of ZnO and vanadium ions were incorporated into the lattice of zinc oxide. SEM images showed that the synthesized pure zinc oxide has irregular morphology and with adding vanadium dopant, rod and cube-like morphology appeared. The band gap energy of pure ZnO decreased from 3.3 to 3.21 eV on adding 1% vanadium. The results showed that the zinc oxide doped with 1% vanadium exhibited better photocatalytic activity compared to other samples. The possible mechanism for improving of photodegradation efficiency of doped samples was also discussed. K E Y W O R D S microemulsion, nanoparticles, photocatalyst, vanadium, ZnO

Vanadium promoted ZnO films: Effects on optical and photocatalytic properties

“…Optical investigations show the creation of local energy states after doping, and photocatalytic activity augmentation can be explained by localized-state charge trapping, increased surface area, and porosity [37]. Studies regarding the effect of transition metal doping on the photoelectrochemical properties of metal oxide films have been widely available in literature, some of which indicate that vanadium (V) doping improves the UV sensibility and photoresponse of ZnO, TiO 2 , and α-Fe 2 O 3 metal oxides by increasing the rate of visible light absorption, leading to increased photocatalytic activity [38][39][40][41][42]. Photocatalytic degradation studies of organic dyes [43][44][45] and synthesis/characterization studies of vanadium doped ZnO nanostructures [46][47][48] have been reported, however there is a gap about a comparative study regarding the influence of various oxidation states of vanadium.…”