Multifunctional 2D membranes with interstitial nanofluidic channels are of great significance for controllable ion transport and osmotic energy conversion. Herein, the robust photothermal-responsive 2D hybrid membranes based on the near-parallel laminar stacking of black phosphorus (BP) and montmorillonite (MMT) nanosheets reinforced by cellulose nanofibers (CNF) are developed. The resultant hybrid membrane exhibits cationic selectivity and surface-charge-governed ion transport properties. The photothermal effect of BP nanosheets increases the surface temperature of the hybrid membrane under illumination, which contributes to enhanced ion transport. This photothermal-enhanced ion transport boosts the maximum power density of osmotic energy conversion from 4.84 to 5.31 W·m-2 by 9.7% at a 50-fold concentration gradient under 400 mW·cm-2 simulated sunlight. This work reveals the integration of the photothermal effect of BP nanosheets in 2D nanofluidic membranes, providing a possible route to enhance the osmotic energy conversion performance by renewable light energy.
Keywords: black phosphorus; ion transport; montmorillonite; osmotic energy; photothermal.
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