Paper Title
Synthesis of Nayf4:Yb,Ho/Tio2 Composite Aerogel Designed for Selective Layer of Ceramic Membrane

Abstract
Air and water contamination have been serious problems in the world. In order to solve these problems, membrane filtration processes have drawn great attention owing to their high efficiency separation technique. In the present study, NaYF4:Yb,Ho/TiO2 composite aerogel is designed as a selective layer for an inorganic ceramic membrane in the membrane filtration separation process. The NaYF4:Yb,Ho/TiO2 composite aerogel is successfully fabricated by a sol-gel process and a supercritical drying process. The NaYF4:Yb,Ho/TiO2 composite aerogel with high specific surface area absorbs the near-infrared (NIR) light and transfers it to the visible region. The size of NaYF4:Yb,Ho NPs is approximately 50 nm and the crystal size of TiO2 is around 10 nm. The larger NaYF4:Yb,Ho NPs were surrounded by TiO2 aerogel. The NaYF4:Yb,Ho/TiO2-H composite aerogel shows the highest specific surface area owing to the completely formation of TiO2 aerogel structure and without the aggregation of NaYF4:Yb,Ho NPs. Index Terms— TiO2 aerogel, NaYF4:Yb,Ho, Ceramic Membrane, Water Purification.