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Metal–organic frameworks (MOFs) with long‐term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT‐66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT‐66 (V3(O)3(H2O)(BTB)2), possesses prominent moisture tunability in the range of 45–60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption–desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials.

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Creation of functional patterns in two-dimensional (2D) materials provides opportunities to extend their potential for applications. Transition-metal dichalcogenides (TMDCs) are suitable 2D materials for pattern generation because of properties including alterable polymorphic phases, easy chalcogen-vacancy formation, metal-atom insertion, and alloying. Such patterning can be used for selective functionalization. Here we report the spontaneous formation of long-range, well-ordered 1D patterns in monolayer vanadium diselenide (VSe2) by a single annealing stage during growth. Atomic-resolution images in real space combined with density-functional-theory (DFT) calculations reveal the 1D features of patterned VSe2. Further experimental characterization of the intermediate states in the growth process confirm the spontaneous formation of the 1D pattern by annealing-induced Se-deficient linear defects. The 1D pattern can be reversibly transformed to homogenous VSe2 monolayer by reintroducing Se atoms. Moreover, additional experiments demonstrate that a dispersive deposition of Pt atoms along the 1D structures of patterned VSe2 is achieved, while DFT calculations find that their catalytic activity for hydrogen evolution reaction (HER) is as good as that of Pt surfaces. The formation of long-range, well-ordered 1D patterns not only demonstrates an effective way of dimension modulation in 2D materials but also enriches the potential of intrinsically patterned 2D materials for promising catalytic activities.

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Two-dimensional (2D) Ti3C2T X MXene has been a promising nanomaterial in energy storage, electromagnetic shielding, and sensors. However, MXene suffers from major drawbacks of unstable structure and vulnerable oxidation in ambient moisture. Herein, a facile strategy is proposed to address the challenging problems via oxygen-rich molecular bridging. The tannic acid bridging agent with abundant O-containing ligands can self-polymerize and bind at the terminal groups and exposed Ti atom of Ti3C2T X by a synergistic hydrogen bond and coordination bond. The enhanced interlaminar interaction endows the MXene film with resistance to oxidation, swelling, and mechanical fragility. Density functional theory calculations prove that the charge transfer from MXene to oxygen-rich molecules improves the interface electronic structure, thus enlarging the work function of pristine Ti3C2T X , which means increased resistance toward losing electrons and being oxidized. The resultant bridged MXene film achieves 7 times toughness enhancement compared with pristine MXene, stable conductivity during the long-term storage in a humid environment, excellent structural and electrochemical stability during 10 000 cycles in aqueous electrolytes, and a remarkable energy density of 53.3 mW h cm–3 used for flexible symmetric micro-supercapacitors. This work opens opportunities for the rational design and fabrication of robust 2D MXene assemblies for aqueous energy storage.

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