Hierarchically Structured Self-Floating Multilayer Evaporator Based on Polyaniline/Carbon Black Functionalized Carbon Fiber Paper for Efficient Solar Desalination

Solar-driven interfacial evaporation has emerged as a transformative technology for sustainable seawater desalination. While significant advancements have been made in enhancing evaporation rates through material selection and architectural optimization, mitigating parasitic heat loss remains a critical technical bottleneck. In this work, we present a hierarchically structured, self-floating multilayer evaporator utilizing carbon fiber paper (CP) functionalized with polyaniline (PAN) and carbon black (CB) as the photothermal layer. The designed architecture leverages a delignified wood (DW) block as an efficient hydrophilic water-pumping scaffold, coupled with a modified hydrophobic carbon paper (CP@PAN-CB) to effectively localize heat and suppress downward conduction to the bulk water. Systematic investigation reveals that the sequential doping of PAN followed by CB creates a synergistically high-dispersion interface that bolsters light-harvesting efficiency. Under one-sun irradiation (1 kW m −2 ), the evaporator attains a stable surface temperature of approximately 65°C within 60 s and achieves a peak evaporation rate of 1.593 kg m −2 h −1 in seawater. Furthermore, the system demonstrates exceptional long-term stability with negligible salt crystallization over continuous 8-h testing. This work highlights the potential of gradient hydrophilicity and optimized photothermal functionalization for robust and efficient solar-driven water purification.