No abstract

A 2D membrane-based separation technique has been increasingly applied to solve the problem of fresh water shortage via ion rejection. However, these 2D membranes often suffer from a notorious swelling problem when immersed in solution, resulting in poor rejection for the monovalent metal ion. The design of the antiswelling 2D lamellar membranes has been proved to be a big challenge for highly efficient desalination. Here a kind of self-crosslinked MXene membrane is proposed for ion rejection with an obviously suppressed swelling property, which takes advantage of the hydroxyl terminal groups on the MXene nanosheets by forming Ti–O–Ti bonds between the neighboring nanosheets via the self-crosslinking reaction (−OH + −OH = −O– + H2O) through a facile thermal treatment. The permeation rates of the monovalent metal ions through the self-crosslinked MXene membrane are about two orders of magnitude lower than those through the pristine MXene membrane, which indicates the obviously improved performance of the ion exclusion by self-crosslinking between the MXene lamellae. Moreover, the excellent stability of the self-crosslinked MXene membrane during the 70 h long-term ion separation also demonstrates its promising antiswelling property. Such a facile and efficient self-crosslinking strategy gives the MXene membrane a good antiswelling property for metal ion rejection, which is also suitable for many other 2D materials with tunable surface functional groups during membrane assembly.

Membrane‐based reverse electrodialysis (RED) is considered as the most promising technique to harvest osmotic energy. However, the traditional membranes are limited by high internal resistance and low efficiency, resulting in undesirable power densities. Herein, we report the combination of oppositely charged Ti3C2Tx MXene membranes (MXMs) with confined 2D nanofluidic channels as high‐performance osmotic power generators. The negatively or positively charged 2D MXene nanochannels exhibit typical surface‐charge‐governed ion transport and show excellent cation or anion selectivity. By mixing the artificial sea water (0.5 m NaCl) and river water (0.01 m NaCl), we obtain a maximum power density of ca. 4.6 Wm−2, higher than most of the state‐of‐the‐art membrane‐based osmotic power generators, and very close to the commercialization benchmark (5 Wm−2). Through connecting ten tandem MXM‐RED stacks, the output voltage can reach up 1.66 V, which can directly power the electronic devices.

The uncontrolled release of antibiotics and pharmaceuticals into the environment is aw orldwide increasing problem. Thus,h ighly efficient treatment technologies for wastewater are urgently needed. In this work, seven kinds of typical antibiotics (including water and alcohol soluble ones) are successfully separated from the corresponding aqueous and ethanolic solutions using highly regular laminated membranes. Our membranes are assembled with 2-4 mmt itanium carbide nanosheets.T he solvent permeance through such titanium carbide membrane is one order of magnitude higher than that through most polymeric nanofiltration membranes with similar antibiotics rejection. This high flux is due to the regular two-dimensional (2D) structure resulting from the large aspect ratio of titanium carbide nanosheets.M oreover,t he electrostatic interaction between the surface terminations and the antibiotics also affects the rejection and enhances the antifouling property.S uch2 Dt itanium carbide membranes further broaden the application scope of laminated materials for separation and purification of high value added drugs in academia and industry.

No abstract

No abstract

Membrane‐based reverse electrodialysis (RED) is considered as the most promising technique to harvest osmotic energy. However, the traditional membranes are limited by high internal resistance and low efficiency, resulting in undesirable power densities. Herein, we report the combination of oppositely charged Ti3C2Tx MXene membranes (MXMs) with confined 2D nanofluidic channels as high‐performance osmotic power generators. The negatively or positively charged 2D MXene nanochannels exhibit typical surface‐charge‐governed ion transport and show excellent cation or anion selectivity. By mixing the artificial sea water (0.5 m NaCl) and river water (0.01 m NaCl), we obtain a maximum power density of ca. 4.6 Wm−2, higher than most of the state‐of‐the‐art membrane‐based osmotic power generators, and very close to the commercialization benchmark (5 Wm−2). Through connecting ten tandem MXM‐RED stacks, the output voltage can reach up 1.66 V, which can directly power the electronic devices.

The uncontrolled release of antibiotics and pharmaceuticals into the environment is a worldwide increasing problem. Thus, highly efficient treatment technologies for wastewater are urgently needed. In this work, seven kinds of typical antibiotics (including water and alcohol soluble ones) are successfully separated from the corresponding aqueous and ethanolic solutions using highly regular laminated membranes. Our membranes are assembled with 2–4 μm titanium carbide nanosheets. The solvent permeance through such titanium carbide membrane is one order of magnitude higher than that through most polymeric nanofiltration membranes with similar antibiotics rejection. This high flux is due to the regular two‐dimensional (2D) structure resulting from the large aspect ratio of titanium carbide nanosheets. Moreover, the electrostatic interaction between the surface terminations and the antibiotics also affects the rejection and enhances the antifouling property. Such 2D titanium carbide membranes further broaden the application scope of laminated materials for separation and purification of high value added drugs in academia and industry.