Effect of lithium codoping on the structural, morphological and photocatalytic properties of Nd-doped ZnO

Nanostructured ZnO: Nd nanoparticles (NPs) codoped with lithium at low temperature and short synthesis time were prepared using the polyol method, and the influence of different lithium contents at constant atomic concentration of Nd was evaluated. The resulting materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller analysis (BET), X-ray photoelectron spectroscopy (XPS), and optical spectroscopies (photoluminescence (PL), cath-odoluminescence (CL) and Raman). X-ray diffraction patterns demonstrate that the materials are polycrystalline with a wurtzite structure with no secondary phases in the concentrations evaluated. The unit cell parameters were determined, and the crystallite size was calculated considering the three most intense diffraction peaks. TEM shows that the particles are polycrystalline with no amorphization. Raman analysis further confirms the wurtzite hexagonal structure of the particles. Morphological and size studies using SEM and TEM show that the most remarkable change is the evolution from hemispherical ZnO NPs to spindle-shaped particles for Li-Nd doped ZnO. The surface chemistry, as studied by X-ray photoelectron spectroscopy (XPS), confirms the incor-poration of Nd3+. The study of the photocatalytic behavior of the Li-Nd codoped ZnO NPs reveals that the ZNL0.5 sample exhibits the highest photocatalytic activity using a solution of Rhodamine B (2.5 ppm) as a reference.

Automated summary

Nanostructured ZnO: Nd nanoparticles codoped with lithium were prepared by the polyol method at low temperature and short synthesis time. The influence of different lithium contents on the properties of the materials was investigated. The results showed that the materials had a polycrystalline wurtzite structure without any secondary phases. The morphological and size studies indicated a change from hemispherical ZnO nanoparticles to spindle-shaped particles in the Li-Nd doped ZnO samples. XPS analysis confirmed the incorporation of Nd3+ in the materials. The Li-Nd codoped ZnO nanoparticles exhibited the highest photocatalytic activity in the presence of Rhodamine B.