Synthesis and UV-shielding Property of Plate-like Potassium Lithium Titanate Coated with Calcia-doped Ceria Nanoparticles

Abstract

In order to attain further performance improvements concerning UV-shielding, the synthesis parameters of plate-like lepidocrocite related potassium lithium titanate were optimized and calcia-doped ceria (Ce_0.8Ca_0.2O_1.8) nanoparticles were coated on plate-like potassium lithium titanate (K_0.8Li_0.27Ti_1.73O₄), 10-20 μm in diameter via solution processes, where the plate-like titanate was prepared by reacting K₂CO₃, Li₂CO₃ and TiO₂ using KCl flux at 950°C. After putting plate-like potassium lithium titanate particles in deionized water at 40°C, appropriate quantities of 3 M NaOH aqueous solution and 0.8 M CeCl₃-0.2 M CaCl₂ mixed aqueous solution were simultaneously dropped, where the solution was stirred and pH was kept at 12 throughout the reaction. Then, the desired amount of 2 M H₂O₂ solution was added and pH was also kept at 12. The slurry was filtrated and washed with water and methanol. The precipitate was fired at 700°C for 1 h to obtain plate-like K_0.8Li_0.27Ti_1.73O₄ coated with white Ce_0.8Ca_0.2O_1.8 nanoparticles. Such panoscopic assembling successfully improved the comfort of the product when wearing it on the skin without compromising the UV-shielding ability, meanwhile greatly reducing the oxidation catalytic activity.