Self-assembly of honeycomb-like calcium-aluminum-silicate-hydrate (C-A-S-H) on ceramsite sand and its application in photocatalysis.

In recent years, stabilization and dispersion of catalysts and adsorbents have been widely studied in the field of air and water pollution treatment. In this paper, a novel functional carrier, ceramsite sand (CS) with honeycomb-like C-A-S-H (CSHC) was synthesized by spontaneous self-assembly of C-A-S-H. The self-assembly conditions, mechanisms and physicochemical properties of honeycomb-like C-A-S-H were studied in detail. The results show that C-A-S-H on the surface of CS has a honeycomb-like structure comprising numerous nanoscale cells in the range of 50–300 nm, which results in an increase of the specific surface area by more than 46 times. In addition, Ag/AgBr loaded ceramsite sand with honeycomb-like C-A-S-H (ACSHC) was prepared for further application. The Ag/AgBr nanoparticles were homogenously embedded into the honeycomb-like structure of C-A-S-H with a close and robust contact. Therefore, the photocatalytic efficiency of ACSHC is improved significantly and remains nearly 100% after 5 months. The results suggest that the novel self-assembly C-A-S-H with a honeycomb-like structure could provide a high specific surface area, good pore structure and more active sites. It is a promising functional carrier for catalysts or adsorbents in the field of air and water pollution treatment. [ABSTRACT FROM AUTHOR]