| 研究実績の概要 |
Ti3C2Tx MXene sheets with high hydrophilicity are being considered for gas separation applications. Herein, we prepared MXene/graphene oxide (GO) composite membranes at different GO concentrations with smaller interlayer spacing and aligned platelets for a better separation performance. The membranes were fabricated by vacuum filtration of MXene/GO suspension at different GO compositions on AAO substrate. The membranes thickness was adjusted between 20 nm to 100 nm with an exact volume of the suspension.
FTIR, XPS spectra revealed the interactions between MXene platelets and GO monolayer through Ti-O-C covalent bonds. Moreover, XPS and UV absorbance indicated the reduction of GO sheets by MXene. X-ray scattering exhibited that the d-spacing of MXene increases from 11.4 A to 13.5 A; at low GO contents, which explained the interlamellar insertion of GO into MXene has occurred. The stability and mechanical properties of the MXene/GO membranes improved compared to the pure MXene due to the Ti-O-C covalent bonding. N2 adsorption measurement showed a decrease in pore volume and gas uptake of MXene membranes by the addition of GO, which was attributed to the Ti-O-C covalent bonds and improvement in the alignment degree. The gas permeance of the composite membranes decreased down to half of its pure MXene value by adding GO because of the smaller pore volume. However, the H2/CO2 selectivity significantly improved from 115 for pure MXene to 536 for MX50GO50, indicating a better sieving ability in the composite membranes.
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