Abstract: By varying the concentration of APS aqueous solution, reaction time and temperature, a series of silica-pillared layered niobic acids with different interlayer distances, surface areas, pore sizes and thermostability were successfully prepared. It was shown that increasing the concentration of APS aqueous solution under a certain level(from 2.1% to 10%) led to the formation of silica-pillared layered niobic acids with a gradually increased interlayer distance, surface area and silica pillar density, and therefore a gradually decreased pore size, but the same thermostability. On the other hand, reducing reaction time from 3 days to 1 day caused the decrease of the interlayer distance, surface area and thermostability, but the increase of pore size due to lower pillar density. Furthermore, the reaction at room temperature gave rise to the silica pillared layered niobic acid with a smaller interlayer distance and pore size, a slightly larger specific surface area and a lower thermostability.

Key words: Layered niobic acid, Silica, Pillaring