Porous zincite prepared by the calcination of colloidal starch applied in the removal of dyes and its use as a hybrid pigment

Abstract

A mesoporous zincite with a surface area of 10.34 m2 g−1, a pore volume of 0.030 cm3 g−1, and a pore radius of 1.98 nm was prepared using a colloidal dispersion of starch, calcined at 600 °C, and the resulting material was identified as the hexagonal wurtzite phase. The porous colorless zincite (PCZ) was used for the removal of textile dyes (blue and red) and removed 99.87% of blue dye, and 99.76% for red dye, owing to fast electrostatic interaction, leading to the formation of colored zincite as a hybrid pigment (HyPi). The HyPiblue and HyPired were combined with commercial white paint (10%, w/w), and its colorimetric characteristics (L*a*b*) were maintained with a decrease in the degree of reflectance in the visible-NIR region. After 48 h continuously exposed under the light to check the photoaging, the hybrid pigments dispersed in paint suggested high stabilities for the pigments. In this sense, the current study reveals a new strategy for the application of adsorbent containing toxic compost as a hybrid pigment ensuring the decrease of toxic elements in the environment.