Effect of ethanol washing of titania clay mineral composites on photocatalysis for phenol decomposition

A mesoporous material of titania and clay minerals was prepared from TiOSO4 and Laponite, hectorite, beidellite and saponite. The impact of ethanol washing before calcination on the structure and photocatalytic activity for phenol decomposition was investigated. As comparison, conventional titania pillared clay minerals were also prepared. The mesoporous material had more mesopores and better crystallized anatase particles than conventional pillared clay minerals. The photocatalytic activity of the mesoporous material was far better than that of the conventional pillared clay minerals. Thus, mesopores and larger anatase crystals were beneficial to the photocatalysis. The specific surface area and pore volume of the mesoporous material, which was obtained by washing with ethanol, were larger than those of the sample without ethanol washing. The photocatalytic activity of the ethanol washed samples was 2–6 times higher than that of the corresponding sample without ethanol washing. The main reasons for the high activity were the ethanol washed samples had larger specific surface area and pore volume, and they could be readily dispersed in water. The structure of samples was investigated by XRD, TEM equipped with EDS and N2 adsorption–desorption method.