Durable Antibacterial\nPhotothermal Membrane Using\nMelanin-Inspired Cu-Doped Polynorepinephrine for Water Remediation

Solar-driven interfacial evaporation is an efficient\napproach to\naddressing water scarcity due to its environmental sustainability.\nHowever, the prolonged use of solar evaporators causes microbial contamination\nfrom wastewater. Inspired by the antifouling properties of polydopamine,\nwe develop a series of mono- and dual-metal-loaded poly(norepinephrine)\n(PNE) nanoparticles by pre-doping multiple metal ions. Metal doping\nenhances the photothermal conversion efficiency (∼60%) of PNE\nby reducing the energy bandgap and imparts antimicrobial properties.\nCu<sup>2+</sup>-loaded PNE (Cu-5) combined with laser achieves a 99.72%\nbactericidal rate against both <i>E. coli</i> and <i>S. aureus</i>. The Cu-5-coated cellulose membrane (Cu-5@CM)\nrealized an evaporation rate of 2.21 kg m<sup>–2</sup> h<sup>–1</sup> under one sun with an evaporation efficiency of 97.4%.\nCu-5@CM exhibits remarkable anti-biofouling properties, maintaining\nits surface integrity and evaporation performance even after 15 days\nof immersion in a bacterial environment. Its stable evaporation rate\nand long-lasting antimicrobial performance offer a promising solution\nto the biofouling challenges in seawater desalination.