Light-Boosted Osmotic Energy Conversion and Ion Pumping through a Graphdiyne Oxide-Based Membrane

Two-dimensional (2D) membranes with engineered light-responsive ion transport dynamics have been explored to construct efficient nanofluidic platforms that show great potential in osmotic and solar-osmotic energy conversion. However, the power density is still limited by poor responsivity and the inevitable trade-off effect between ion selectivity and flux. Here, we observed light-pumping ion transport behavior in graphdiyne oxide (GDYO) with a unique carbon hybrid skeleton that provides sensitive photoelectric responsivity and high-speed cation pathways. Molecular dynamics simulations verify that the coexistent interaction effects between cations and the negatively charged sites in GDYO (i.e., oxygen-containing groups and electron-rich acetylenic bonds) could significantly promote cation transmembrane transport via an absorption-acceleration mechanism. Furthermore, the GDYO-based system, possessing a coupled photon-electron-ion transport behavior due to its inherent semiconductor properties, could subtly realize unidirectional ion movement, consuming luminous energy either from low concentration to high concentration or vice versa, flexibly promoting the osmotic power density by ∼195% to 11.91 W m^-2.