MXene Molecular Sieving Membranes for Highly Efficient Gas Separation

Gas separation with membrane technology is attractive because of its high efficiency, low energy consumption, and simple operation. Molecular sieving membranes with sufficient and uniform nanochannels that break the permeability-selectivity trade-off are desirable for energy-efficient gas separation, and the arising twodimensional (2D) materials provide new routes for membrane development. For 2D lamellar membranes, disordered interlayer nanochannels for mass transport are usually formed between randomly stacked neighboring nanosheets, which is obstructive for highly efficient separation. Exfoliated MXene nanosheets were used as building blocks to construct 2D laminated membranes for selective gas separation for the first time, as demonstrated using a model system of H2 and CO2. The MXene membranes were fabricated using vacuum-assisted filtration on anodic aluminum oxide support.