Solar-driven desalination coupled with antibiotic degradation in saline aquaculture wastewater enabled by a plasmonic N-In2O3-x interface.

The discharge of saline aquaculture wastewater containing persistent antibiotics poses a growing challenge due to its high salinity, complex composition, and resistance to conventional treatment. Here, we developed a solar-driven treatment process that coupled interfacial evaporation with in situ photocatalytic degradation, enabling simultaneous freshwater production and antibiotic removal without chemical inputs. This process is realized using a defect-engineered plasmonic nitrogen-doped, oxygen-deficient indium oxide interface derived from a metal-organic framework, which integrates rapid water transport, efficient photothermal conversion, and solar-driven reactive species generation. As a result, the system achieved a high evaporation rate of 3.16 kg m-2 h-1, excellent salt resistance, and >97% tetracycline removal within 120 min. Notably, comparable degradation performance was maintained in real aquaculture wastewater, indicating strong resistance to matrix effects under high-salinity conditions. Outdoor field tests further demonstrated stable freshwater production (12.84 kg m-2 day-1) that meets WHO drinking water standards, along with effective antibiotic removal under natural sunlight. With an estimated materials-level cost of approximately $10.7 m-2 under bulk-procurement conditions and stable operation over 10 days, the system demonstrates preliminary potential for modular solar-driven treatment of antibiotic-contaminated aquaculture wastewater.