nterfacial solar steam generation (ISSG) is an emerging technol- ogy for sustainable water production, harnessing solar energy to desalinate seawater and treat wastewater. However, the develop- ment of efficient, cost-effective photothermal materials for these systems remains a challenge. This study investigates the use of FeNi nanoparticles (NPs) coated on bio-inspired substrates— wood sponge (WS) and pine cone (PC)—for ISSG. These sub- strates, enhanced for their high porosity and hydrophilicity, facil- itate water transport via capillary action, whereas the FeNi NPs improve light absorption and photothermal conversion. Results show that both PC/FeNi and WS/FeNi demonstrate high evapo- ration efficiencies, with PC/FeNi outperforming WS/FeNi in terms of evaporation flux and stability across multiple cycles. The PC- based device achieved a solar evaporation flux of 1.73 kg m2 h−1 and an efficiency of 97.59% under 1 sun illumination, showing promise for large-scale desalination. Furthermore, both pho- toabsorbers effectively reduced ion concentrations in seawater, meeting WHO drinking water standards. This study highlights the potential of bio-inspired, 3D structured substrates like PC for efficient and sustainable ISSG applications.

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