Preparation of amorphous carbon membranes synthesized via a glucose-solution hydrothermal method

Carbon-based membranes are in the limelight as novel and high-performance materials for various applications. In this study, microporous carbon membranes were synthesized on porous alumina via a hydrothermal method from aqueous glucose solutions. The operating time and temperature for the hydrothermal treatment by evaluating the surface microstructure of the as-prepared membranes using various techniques like scanning electron microscopy (SEM) and electron probe microanalyzer mapping (EPMA). The SEM micrographs and the EPMA results indicate that the membranes formed were also deposited in the interiors of the porous alumina. A carbon membrane with few pinholes was prepared via a hydrothermal treatment at 200 °C for 5 h. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analyses suggest that the obtained membranes are composed of amorphous carbon, including hydroxy groups. The result of the gas transmission rate (GTR) measurement indicates that the pore size of the amorphous carbon membranes had pores with a diameter of ∼0.3 nm. The ideal gas selectivities for H2/N2, N2/CH4, and H2/SF6 were over Knudsen theoretical values, showing approximately 7.0, 9.5, and 13.5, respectively.