Origin of color in aerosol-derived vanadium-doped zirconia pigments

The preparation of vanadium-zirconia yellow pigments from amorphous spherical V-ZrO2 particles obtained by the hydrolysis of liquid aerosols consisting of a mixture of vanadium (V) oxychloride and zirconium n-propoxide is reported. The composition of the amorphous precursors (V/Zr ratio) and the heating temperature were systematically varied to determine their influence on the optical properties of the pigments. The origin of the yellow color of the pigments was found to be mainly due to the presence of V2O5 in the outer layers of the zirconia grains. A small fraction (similar to 15%) of the total vanadium content was found as vanadium (IV) forming a solid solution with the monoclinic zirconia lattice.