Interfacial Water Harvesting from Air via MIL‐101(Cr)@LiCl‐Doped Hydrogel for Contact‐Electro‐Catalytic Antibacterial and Hydrogen Production

Humid environment leads to microbial growth, and adsorption of droplets containing bacteria can purify the air. The main challenges are high adsorption rate of water vapor and bacteria killing. A new composite adsorbent MIL-101(Cr)@LiCl (ML) is prepared by encapsulating LiCl in MIL-101(Cr), and it is doped into the skeleton of PAAcK hydrogel. By modulating the ML content within the hydrogel matrix, the H₂O capture capability, Contact-Electro-Catalytic (CEC) performance, and conductivity of PAAcK@MIL-101(Cr)@LiCl (PML) are tuned, enabling the innovative integration of continuous water capture and efficient environmental purification. When adding 10% ML, the moisture absorption rate increased by 2.28 times (2.48 g g^-1). Monte Carlo simulation shows that the moisture absorption is mainly contributed by Cr³⁺, F, and -COOH in MIL-101(Cr). The antibacterial mechanism of CEC caused by the contact between water and PML is innovatively proposed. The doping of ML leads to the decrease of charge transfer barrier. Chemical reaction driven by charge transfer, OH, and ·O₂ ^- are detected, and the antibacterial rate of PML reached 99.97%. By designing the sandwich structure and customizing the directional transmission of water to the electrode interface, the hydrogen production from air reached 149.63 L m² h^-1, and the Faraday efficiency is close to 90%.