Effect of Thermal Treatment on the Structure and Morphology of Vanadium Doped ZnO Nanostructures Obtained by Microwave Assisted Sol–Gel Method
Cristina Maria Vlăduț,
Oana-Cătălina Mocioiu,
Silviu Preda,
Jeanina Pandele-Cusu,
Veronica Bratan,
Roxana Trusca,
Maria Zaharescu
Affiliations
Cristina Maria Vlăduț
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
Oana-Cătălina Mocioiu
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
Silviu Preda
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
Jeanina Pandele-Cusu
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
Veronica Bratan
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
Roxana Trusca
Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 011061 Bucharest, Romania
Maria Zaharescu
Institute of Physical Chemistry Ilie Murgulescu of the Romanian Academy, 202 Splaiul Independenţei, 060021 Bucharest, Romania
In this paper, we conducted a fundamental study concerning the effect of thermal treatment on the structure and morphology of 2 mol% vanadium doped ZnO nanopowders obtained by microwave assisted sol–gel method (MW). The samples were analyzed by DTA, FTIR, XRD, SEM, and UV–Vis spectroscopy. The DTA results showed that above 500 °C, there was no mass loss in the TG curves, and ZnO crystallization occurred. The XRD patterns of the thermally treated powders at 500 °C and 650 °C showed the crystallization of ZnO (zincite) belonging to the wurtzite-type structure. It was found that in the 650 °C thermally treated powder, aside from ZnO, traces of Zn3(VO4)2 existed. FTIR spectra of the annealed samples confirmed the formation of the ZnO crystalline phase and V–O bands. The micrographs revealed that the temperature influenced the morphology. The increase in the annealing temperature led to the grain growth. The SEM images of the MW powder thermally treated at 650 °C showed two types of grains: hexagonal grains and cylindrical nanorods. UV–Vis spectra showed that the absorption band also increased with the increasing temperature of thermal treatment. The MW sample annealed at 650 °C had the highest absorption in ultraviolet domain.
