Synthesis of core-shell nanostructured SiO2/TiO2 photocatalysts via atomic layer deposition in a fluidized bed with central tube

Fluidized bed atomic layer deposition is an efficient technique for particle coating with precise control over the film thickness and uniformity at the sub-nanoscale. In this study, a fluidized bed with a central tube is designed, where the central tube has two roles: improve fluidization and deliver precursors separately. The synthesis of core-shell structured SiO2/TiO2 nanoparticle catalysts for photodegradation of tetracycline hydrochloride (TC) is carried out using TiCl4 and H2O as precursors at 180 degrees C under atmospheric pressure. Under the combination of vibration and central tube, the segregation of agglomerate size along the bed height is weakened, and the prepared SiO2/TiO2 nanoparticles show excellent photocatalytic degradation performance: the degradation efficiency on TC is 96% under 300 W xenon lamp irradiation for 60 min. The mechanism of enhanced photocatalytic activity is due to the Ti-O-Si bonds generated at the interface, which increase the ability to absorb sunlight and accelerate the separation of holes and electrons. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.