Micro–Macro Synergistic Engineering of Metal-Organic Framework-Intercalated GO Membranes for Efficient Solar-DrivenWater-Electricity Cogeneration

Solar-driven interfacial evaporation and thermoelectric cogeneration present sustainable pathways to address global water and energy scarcity. Among various photothermal materials, 2D graphene oxide (GO) membrane evaporators have attracted considerable attention. However, they suffer from restricted water transport and poor heat localization, leading to unsatisfactory evaporation performance. Herein, we report a micro-macro synergistic engineering strategy to construct ZIF-8-intercalated GO composite membranes with a central macroscopic perforation (GO-MOF30-1.5) for efficient solar water-electricity cogeneration. At the microscale, the intercalation of ZIF-8 nanoparticles expands the interlayer spacing, creates abundant light-trapping sites, and enhances both water transport and photothermal conversion. At the macroscale, the central hole eliminates the "evaporation dead zone", improves thermal convection, and accelerates vapor escape. Benefiting from this hierarchical design, the optimized GO-MOF30-1.5 membrane achieves a broadband solar absorptance of 86.21% under one sun. Consequently, it delivers a high evaporation rate of 1.53 kg m-2 h-1 with an outstanding evaporation efficiency of 91.91%. The membrane also exhibits excellent salt tolerance and long-term cycling stability. When coupled with a thermoelectric module, the system produces a stable open-circuit voltage of 135 mV under one sun, which can be amplified to 308 mV by connecting three units in series. Outdoor tests further demonstrate a daily freshwater yield of 3.75 L m-2 and a continuous voltage output of 218 mV (two units in series). This micro-macro synergistic optimization strategy offers a feasible approach for decentralized water purification and electricity supply in remote or off-grid locations, showing great promise for environmentally friendly and sustainable growth.