Effect of transition metal oxides addition on the color tone of Bi4V2O11-based red pigments

Bi4V2O11 (BiVO) is an Aurivillius-type layered compound that exhibits a red color, and has been attracting attention for its non-toxicity. In this study, we have synthesized a variety of metal oxide-doped Bi4V2O11, and aimed to evaluate the effect of the doped metal element on the color tone of the pigments. Bi2O3 and V2O5 were weighed to 2:1 in mole fraction and mixed in a dry-ball mill with zirconia media for 10 min. Next, transition metal oxides (MnO2, α-Fe2O3, CoO, NiO, CuO, TiO2, ZrO2, and HfO2) were added to the Bi2O3–V2O5 mixture, and they were mixed, and calcined at 800 °C in the air for 10 h. The obtained powders were pulverized to obtain sample pigments, BiVO and BiXVO (X = Mn, Fe, Co, Ni, Cu, Ti, Zr, and Hf). The BiVO pigment had a brownish-red color. The BiFeVO, BiNiVO, BiTiVO, BiZrVO, and BiHfVO pigments demonstrated orangish-red colors. The BiCuVO pigment displayed a dark and dull yellow, and the BiMnVO and BiCoVO pigments showed black achromatic colors, which were verified by UV–Vis spectroscopy.