Chlorophyll-Inspired Magnesium Porphyrin Array Membrane for Vis-Light-Enhanced Osmotic Energy Conversion

Osmotic energy, a renewable clean energy, can be directly converted into electricity through ion-selective membranes. Inspired by the magnesium porphyrin (MgP) in plant chlorophyll, which absorbs vis-light and promotes photoelectric conversion, we demonstrate a MgP array membrane, realizing vis-light-enhanced ion transport regulation ability and osmotic energy conversion. The MgP arrays are self-assembled by a MgP-cored block copolymer under the coordination effect of block copolymer self-assembly and MgP π-π stacking, providing chloride-selective transport channels. Due to the unique photochemical properties of MgP, the chloride ion transport conductance and selectivity can be simultaneously increased under visible-light irradiation, benefiting the osmotic energy conversion. Specifically, the maximum power density increases from 26.7 to 34.5 W·m^-2 after visible-light illumination, representing approximately a 30% increase. The construction of MgP arrays realizes photofacilitated osmotic energy conversion, providing an idea for designing an efficient photoelectric conversion system.