Ag Modified Pinecone Photoabsorber for Highly Efficient Interfacial Solar Steam Generation and Wastewater Treatment

Interfacial solar steam generation (ISSG) offers a sustainable and environmentally friendly strategy for addressing the energy and water crises. In this study, we fabricated a highly efficient and cost-effective plasmonic photoabsorber for ISSG of seawater by coating silver nanoparticles (Ag NPs) on pinecone (PC). The PC with low thermal conductivity and numerous aligned microchannels for fast water transport, provides sufficient water supply and reduces the bulk heat loss. In addition, Ag NPs strongly absorb solar radiation through the surface plasmon resonance effect. Using Ag/PC under 1 sun (1 kW m^–2), we achieved an evaporation flux and efficiency of 1.82 kg m^–2 h^–1 and 100%, respectively. Moreover, Ag/PC removed more than 99% of Na⁺, K⁺, Mg²⁺, and Ca²⁺ ions from seawater. The plasmonic PC also exhibited excellent cycling during 10 cycles efficiency of ISSG. Furthermore, treatment of paper industry wastewater with Ag/PC resulted in a significant decrease in the concentration of ions.