2D MOFs-based Materials for the Application of Water Pollutants Removing: Fundamentals and Prospects

Defect Engineering in GO Membranes - Tailoring Size and Oxidation Degree of Nanosheet for Enhanced Pore Channels

Graphene Oxide (GO) membrane has been extensively applied in the field of water purification and membrane separation processes. While the solute molecule transport in GO membranes encompasses interlayer channels, edge defects, and in-plane crack-like holes, the significance of edge defects or crack-like pores in ultrathin membranes is often overlooked. In our study, we focused on the construction of short-range channel GO membranes with varied defect structures by modulating the transverse size of the porous nanosheets. GO nanosheets with different sizes were procured through high-energy γ-irradiation combined with centrifugation. Notably, the large-sized porous GO nanosheets (L-pGO) exhibit a consistent structure, and numerous in-plane defects. In contrast, the smaller counterparts (S-pGO) present a fewer in-plane defects. The performance metrics revealed that L-pGO exhibited a water flux of 849.25 L m-2  h-1  bar-1 , while S-pGO demonstrated nearly 100 % dye rejection capacity. These findings underscore the potential of defect engineering as a powerful strategy to enhance the efficiency of two-dimensional membranes.

Functional Materials for Water Restoration: A "Fish Cage" for Efficient Capture of Pb(II) Ions

In this work, a "fish cage" material for trapping Pb(II) ions has been successfully obtained, which is a novel clathrate functionalized metal-oganic framework (Cage-MOF) by introducing free adsorption sites (SO42-). The three-dimensional (3D) cage structure of Cage-MOF gives it a larger contact area and can capture "swimming fish" (Pb(II)) like a "fishing cage" in a water solution. This is the first high-efficiency adsorption material obtained by introducing free coordination groups. Cage-MOF not only has excellent water stability but also improves the selectivity and affinity for Pb(II) ions in water because of the presence of sulfate adsorption sites, and its adsorption capacity is as high as 806 mg/g. This work shows a novel and effective idea for the synthesis of water restoration materials.

Embedding Lanthanide Organic Polyhedra into Mesoporous Silica Nanoparticles for the Photocatalytic Degradation of Organic Dyes

Organic pollutants cause severe environmental problems because of their damage to human health and ecological systems. Photocatalytic degradation of persistent organic pollutants is of great importance to address these hazards. Herein, we report a lanthanide organic polyhedra-based hybrid material Gd₈ L₁₂ ⊂MSN with the capability of photocatalytic dye degradation. Gd₈ L₁₂ ⊂MSN was prepared by embedding the Gd₈ L₁₂ complex into mesoporous silica nanoparticles (MSNs) using a "ship-in-a-bottle" strategy. Photocurrent response tests revealed that this hybrid material is a potential semiconductor and could generate a rapid and steady photocurrent upon irradiation. Further dye degradation experiments indicated that it could photocatalyze the degradation of familiar organic dyes. Thereinto, compared with the critical Gd₈ L₁₂ complex, the hybrid material exhibited an acceleration of 2.4 times and realized reusability. This not only offers a potential advanced photocatalyst for degrading persistent organic pollutants, but also provides a strategy for the application of supramolecular materials in environmental science.