Simultaneous growth of graphene/mesoporous silica composites using liquid precursor for HPLC separations

Silica intercalated graphene-silica composites (G/SiO 2 ) were prepared by one-step hydrothermal method. In the previously reported one-step method for synthesizing G/SiO 2 composites (eg. Bull. Mater. Sci., 37 (2014), 589–595; Applied Surface Science 259 (2012), 566–573), graphene needs to be synthesized first and then used to prepare G/SiO 2 composites. In this work, neither the preparation of graphene nor the use of graphite as a carbon source is required for the preparation of G/SiO 2 composites. Instead, organic solvent (such as toluene, xylene, mesitylene, n-hexane, n-heptane, and cyclohexane) was directly used as the carbon source, and the growth and recombination of graphene and SiO 2 were achieved simultaneously through a one-step hydrothermal method. In a hydrothermal reaction vessel, the mixture consisting of organic solvent, TEOS, H 2 O, and surfactant was uniformly stirred, and then reacted at 160 °C for 4 h to prepare G/SiO 2 composite. The influence of the type of organic solvent, hydrothermal reaction temperature, and calcination temperature on the structure of G/SiO 2 composites were studied. The morphology and structure of G/SiO 2 composites were characterized by FESEM, TEM, and Raman. The formation mechanism of G/SiO 2 composite was proposed. G/SiO 2 composite was then grown directly on the SiO 2 spheres and used as stationary phase for high performance liquid chromatograph separation. Mixture of hydrocarbons was well separated under reversed phase condition.