Straight-through angstrom-scale channelled MXene nanosheet membranes engineered by heavy ion irradiation for H2 sieving

Heavy ion irradiation introduces straight-through channels in MXene membranes. • ∼3 Å pores with narrow size distribution are generated by Fe ion irradiation. • Heavy ion irradiation can penetrate through micron-thick MXene membranes. • Fe ion irradiation enhances H 2 permeance and H 2 /CO 2 selectivity. Two-dimensional (2D) nanosheets are promising for fabricating H 2 sieving membranes due to their atomic-scale thickness, but the tortuous pathways formed by nanosheet stacking limit efficient gas transport. Introducing artificial in-plane pores on 2D nanosheets offers a solution, yet existing methods suffer from broad size distribution with large pore size and shallow pore-forming depth through membranes. Here, we propose a kind of straight-through angstrom-scale channelled MXene nanosheet membranes for H 2 sieving engineered by a heavy ion irradiation strategy. A key advantage of the pore-forming strategy is that selecting specific heavy ion species and energy enables precise control of energy loss, directly guaranteeing ultra-uniform pore size at the angstrom scale. After Fe ion irradiation, the obtained pores penetrating through micron-thick membranes exhibit size of ∼3 Å with narrow distribution (proportion of 87%), high pore density (>10 13  cm −2 ) and uniform distribution simultaneously. The optimal membranes exhibit an H 2 permeance of 1898 GPU, a sixfold increase over the pristine membrane assembled with nonporous MXene nanosheets, while retaining a high H 2 /CO 2 selectivity of ∼91, outperforming most current membranes. This work provides a scalable strategy for pore-engineering of 2D nanosheet membranes, and establishes a robust platform for gas separation, catalysis, and environmental applications. Download: Download high-res image (331KB) Download: Download full-size image