Excellent Honeycomb‐Networked MOF‐Spindle‐Knotted Fiber Mesh for High‐Efficiently Water Capturing

ABSTRACT Adsorption‐based atmospheric water harvesting (AWH) demonstrates innovative potential in mitigating global water scarcity through efficient vapor capture by means of adsorbent materials. Metal‐organic frameworks (MOFs) are excellent water vapor adsorbents at low humidity. However, MOF as adsorbents in powder form often triggers agglomeration and limits practical application. It remains challenging to design robust materials for water harvesting to date. Here, we present a strategy to design bioinspired honeycomb‐networked spindle‐knotted water molecule capturing fiber mesh on large scale (i.e., BMCM), based on MOF and thermo‐responsive gel polymer using a biomimetic interfacial assembly method. The honeycomb‐networked spindle‐knots of BMCM achieve unique capabilities that regulate the morphology of MOF nanocrystals to expand the water‐molecule sites and favor water uptake, along with thermo‐responsive switching between water uptake (e.g., <30°C) and release (e.g., >30°C). The BMCM exhibits thereby robust water uptake capabilities of ≈0.56–1.05 g g −1 at 30–80% relative humidity (RH), taking a short time rather than others. After reaching its saturation adsorption capacity at 30% RH, it can release ≈0.53 g g −1 of moisture within 30 min under one solar irradiation, with a water release capacity as high as 95%. As for BMCM on large scale outdoor, water production rate reaches ≈3.41 L/kg/day on average after 5‐day cycles in atmospheric air condition. This study provides an insight into the designing of next‐generation AWH materials, which would be extended into applications, e.g., water engineering in industry, outdoor portable system or devices, etc.