Eco-friendly polyfunctional ceramic pigments: an approach

Purpose The purpose of this study is the synthesis and characterization of a CMYK palette (cyan of Cr-BiVO4, magenta of Pr-CeO2, yellow of Bi-(Ce,Zr)O2 composite and black of YMnO3) as an eco-friendly polyfunctional palette that combines (a) high near-infrared reflectance (cool pigments) that allows moderate temperatures in indoor environments and the urban heat island effect; (b) photocatalytic activity for the degradation of organic contaminants of emerging concern of substrates in solution (such as Orange II or methylene blue) and gaseous (NOx and volatile organic compounds such as acetaldehyde or toluene); (c) X-ray radiation attenuators associated with bismuth ions; and (d) biocidal effect combined with co-doping with bactericidal agents. Design/methodology/approach Pigments were prepared by a solid-state reaction and characterized by X-ray diffraction, diffuse reflectance spectroscopy, photocatalytic activity over Orange II and scanning electron microscopy. Findings The behaviour of the proposed palette was compared to that of a commercial inkjet palette, and an improvement in all functionalities was observed. Social implications The functionalities of pigments allow the building envelope and indoor walls to exhibit temperature-moderating effects (with the additional effects of moderating global warming and increasing air conditioning efficiency), purification and disinfection of both indoor and outdoor air, and radiation attenuation. Originality/value The proposed palette and its polyfunctional characterization are novel.