A simple solvothermal preparation of Mg-doped anatase TiO2 and its self-cleaning application

Abstract

Self-cleaning materials have attracted considerable attention for their unique properties and practical applications in energy and environmental areas. Various commercial ceramic products developed based on photo-induced hydrophilic conversion of TiO2 surfaces have also been provided. However, UV light induced and metastable character of anatase TiO2 in medium/high temperature ceramic glaze limited practical applications for self-cleaning photocatalytic materials, which needs further development to improve their efficiency and utilities. In this work, Mg-doped anatase TiO2 was synthesized via a template-free and surfactant-free solvothermal method. The results indicated that MgCl2·6H2O content played key roles in the formation of anatase TiO2. Compared to TiO2-undoped sample, Mg-doped TiO2 sample showed higher photodegradation rate of 99.5 % in 80 min exposed to visible light irradiation. Owing to the introduction of the catalyst, the ceramic glaze showed super-hydrophilicity (water contact angle around 7°) and exhibited excellent stain resistance (e. g. the dried Marker ink on the glaze can immediately float once meeting water after 10 cycles). The glaze after more times recycles could restore super-hydrophilicity is irradiated by visible light for 1 h. This indicates that the introduction of Mg-doped anatase TiO2 demonstrated great practical applications for self-cleaning ceramics toward sunlight.