Synthesis And Evaluation Of Inorganic Bi-V-O Pigments

Bismuth vanadium oxide system pigments were prepared as new ecological colorant pigments. X-ray diffraction, scanning electron microscopy and spectrophotometer were conducted to demonstrate the characteristics of the samples. Synthesis conditions and mechanisms were evaluated and discussed. Purity, grain size and hue of each compound have been also checked and determined.The results show as follow:Firstly, three routes, by turns ceramic method, aqueous solution route and aqueous suspension route, were conducted to prepare BiVO4, Bi4V2Ou and Bi8V2O17. Synthesis methods were proved to be practicable in our study. Comparisons showed that the aqueous solution route yielded a finest powder (around 1/^m).Secondly, on the basis of the enviromental considers, these "green" bismuth pigments were presented to substitute for some toxic inorganic pigments containing chromium, lead, cadmium and so on, like chrome yellow, zinc yellow and lead red.Thirdly, BiVO4 exhibits a brilliant yellow color, while the yellow BigX^On contains a green hue. And the color of Bi4V2On is red. They all behave excellent durability and intensive hues, and temperature point of thermal stability for each compound is over 750℃.Fourthly, BiVO4 exhibits a monoclinic structure, while both Bi4V2Ou and Bi8V2Ol7exhibit an orthorhombic structure.Fifthly, BiVO4 is proved to be a versatile reversible changing color pigment with two color conversion temperature zones: Yellow (ambient temperature) -orange (120℃ -rred (20℃). This compound inherits the thermal chromatism of Bi2Os and V2O5.