Chlorophyll-Inspired\nMagnesium Porphyrin Array Membrane\nfor Vis-Light-Enhanced Osmotic Energy Conversion

Osmotic energy, a renewable clean energy, can be directly\nconverted\ninto electricity through ion-selective membranes. Inspired by the\nmagnesium porphyrin (Mg<i>P</i>) in plant chlorophyll, which\nabsorbs vis-light and promotes photoelectric conversion, we demonstrate\na Mg<i>P</i> array membrane, realizing vis-light-enhanced\nion transport regulation ability and osmotic energy conversion. The\nMg<i>P</i> arrays are self-assembled by a Mg<i>P</i>-cored block copolymer under the coordination effect of block copolymer\nself-assembly and Mg<i>P</i> π–π stacking,\nproviding chloride-selective transport channels. Due to the unique\nphotochemical properties of Mg<i>P</i>, the chloride ion\ntransport conductance and selectivity can be simultaneously increased\nunder visible-light irradiation, benefiting the osmotic energy conversion.\nSpecifically, the maximum power density increases from 26.7 to 34.5\nW·m<sup>–2</sup> after visible-light illumination, representing\napproximately a 30% increase. The construction of Mg<i>P</i> arrays realizes photofacilitated osmotic energy conversion, providing\nan idea for designing an efficient photoelectric conversion system.