All-in-one biomimetic solar desalination for electricity and water cogeneration: role of carbon felt geometry

• A simple and low-cost solar energy-driven water-energy cogeneration system was developed. • Jellyfish-inspired cotton yarns enabled efficient solar water transport. • Achieved high solar evaporation rate of 4.6 kg m −2 h −1 with 257% efficiency. • Carbon felt geometry significantly influenced the electricity generation. • The system exhibited strong salt resistance and self-regeneration for long-term use. Evaporation-driven electricity generation and solar desalination have emerged as promising strategies for sustainable energy and freshwater production. However, both approaches face limitations such as low efficiency, salt accumulation, and system complexity. In this study, a simple, low-cost, and shape-configurable system based on carbon felt placed on polyurethane foam is developed, with water transport enabled via cotton yarns inspired by jellyfish tentacles. The system achieves simultaneous power generation and water purification, with a high evaporation rate of 4.6 kg m −2 h −1 and a conversion efficiency of 257%. The star-shaped geometry exhibits the highest evaporation, corresponding to a 400% increase and a maximum value five times larger than the control. Meanwhile, the circular planar structure delivers the highest electrical output. The system also attains a maximum power density of 0.02 mW m −2 . The electrical output is strongly influenced by the geometry of the carbon felt, revealing a clear structure-performance relationship. The system demonstrates excellent salt resistance and self-regeneration, eliminating the need for cleaning and enhancing long-term stability for at least 168 h. These findings highlight a promising direction for developing integrated water-energy harvesting platforms for simultaneous clean water production and electricity generation.