A novel rutile TiO2/AlPO4 core-shell pigment with substantially suppressed photoactivity and enhanced dispersion stability

Abstract

Decorating inorganic particles with core-shell structure is an attractive approach to broaden their practical application owing to the synergistic effects between inner core and outer shell. In this work, a novel rutile TiO2@AlPO4 core-shell composite has been constructed via a facile one-step wet chemical deposition method. The dense and thick AlPO4 shell can hinder direct contact between TiO2 core and outer environment, decrease light absorption ability, suppress separation of electron-hole pairs, and accelerate electron annihilation. Such unique properties hindered the generation of reactive oxygen species, further contributing to the suppression of photoactivity. The superior dispersion stability in aqueous system of TiO2@AlPO4 core-shell hybrid was attributed to its enhanced surface electronegativity. Thus-produced TiO2@AlPO4 core-shell hybrid with suppressed photoactivity and enhanced dispersion stability could further increase the weather durability and prolong the life span of TiO2-based pigment. Overall, this study provides new insight into the mass production of multi-functional rutile TiO2 pigments.