Zeolite nanosheet–carbon composite films for high-efficiency and salt-resistant interfacial solar evaporation

Interfacial solar evaporation is a promising approach for sustainable water purification. However, its large-scale implementation is limited by complex fabrication methods and salt accumulation issues. In this study, a simple, template-free, and scalable strategy is reported for the fabrication of a zeolite nanosheet–carbon (ZNC) composite film via one-step solution coating and pyrolysis. The carbon matrix provided a broadband solar absorption capability, whereas the embedded zeolite nanosheets enhanced the surface roughness, hydrophilicity, and water transport. Critically, the ZNC film also exhibited a passive salt-rejection capability without requiring polymer membranes or external desalting processes. Under 1 sun illumination, the optimized ZNC film achieved a stable water evaporation rate of ~2.0 kg m⁻² h⁻¹ with a ~91 % solar-to-vapor conversion efficiency. Detailed characterization and control experiments revealed that this performance enhancement arose from multiple synergistic effects, including light trapping due to surface texturing, rapid capillary-driven water replenishment, interfacial water structuring with reduced enthalpic barriers, and efficient heat localization. Long-term operation under saline conditions further demonstrated the robust antifouling behavior and structural stability of the developed system. Overall, this study highlights the potential of zeolite–carbon hybrids for use as practical high-performance evaporators for solar-driven desalination.