Synthesis of Nanoscale WO3 by Chemical Precipitation Using Oxalic Acid
Philipp Yu. Gorobtsov, T. L. Simonenko, Н. П. Симоненко, Е. П. Симоненко, V. G. Sevastyanov, Н. Т. Кузнецов
Abstract
The synthesis of nanoscale WO3 by chemical precipitation with oxalic acid was studied. The obtained powder was characterized by IR-spectroscopy and powder X-ray diffraction, while its thermal behavior was investigated by simultaneous TGA/DSC analysis. It was found that before heat treatment, the precipitate is a mixture of WO3⋅2H2O and tungsten oxalate. The heat treatment at 400°C results in oxalate decomposition, while treatment at 500°C gives single-phase WO3 with monoclinic crystal structure (mean CSR of 36 ± 4 nm, particle length of 50 ± 5 nm, and particle width of 40 ± 4 nm). The electron work function of the surface of prepared WO3 particles in air was measured using Kelvin-probe force microscopy. It was shown that chemical precipitation of tungsten(VI) oxide using oxalic acid is a promising method for producing the corresponding nanopowder.