Graphene oxide-periodic mesoporous silica sandwich nanocomposites with vertically oriented channels.

This paper describes the synthesis and characterization of single-layer graphene oxide-periodic mesoporous silica sandwich nanocomposites. Through a comprehensive exploration of the synthesis conditions, it has proven possible to create the first example of a graphene oxide-periodic mesoporous silica nanocomposite in which hexagonal symmetry PMS film grows on both sides of the graphene oxide sheets with the mesoporous channels vertically aligned with respect to the graphene oxide surface. The formation of this novel architecture is found to be very sensitive to pH, the ratio of surfactant template to graphene oxide, the amount of silica precursor, and the temperature of the synthesis. On the basis of the collected data of a multi-technique analysis, it is proposed that the mode of formation of the nanocomposite involves the co-assembly of silicate-surfactant admicelles on opposite sides of graphene oxide platelets acting thereby as a template for growth of vertical mesopores off the platelet surface. These composites showed semiconductive behavior with electrical conductivity sensitively responding to analyte vapor exposure. The discovery of graphene oxide-periodic mesoporous silica sandwich nanocomposites will provide new opportunities for research that exploits the synergism of the graphene oxide and periodic mesoporous silica parts.