Novel environmentally friendly (Bi, Ca, Zn, La)VO4 inorganic yellow pigments

Abstract

Novel inorganic yellow pigments, Bi_{1−x−y−z}Ca_xZn_yLa_zVO_4−(x+y)/2 (0.04 ≤ x ≤ 0.12; 0.01 ≤ y ≤ 0.05; 0.01 ≤ z ≤ 0.10) were synthesized as environmentally friendly inorganic materials, and their color properties were characterized. All the pigments exhibited brilliant yellow colors, and using the CIE L*a*b* system, the most vivid yellow hue was obtained for Bi_0.85Ca_0.08Zn_0.02La_0.05VO_3.950 with a yellowness value (b*) of +93.5, which is much greater than that of a commercially available BiVO₄ pigment (b* = +76.9). Since BiVO₄ is an environmentally friendly inorganic yellow pigment, and Ca, Zn, and La are also nontoxic and safe elements, the Bi_0.85Ca_0.08Zn_0.02La_0.05VO_3.950 pigment could be an effective alternative to conventional toxic yellow pigments.