High-performance solar vapor generation by sustainable biomimetic snake-scale-like porous carbon

Abstract

Solar vapor generation, which combines the abundant solar energy and unpurified water, is regarded as a promising technique for water production. However, challenges remain in terms of unsatisfactory sunlight absorbability and slow water transportation. Herein, enlightened by scales of West African Gaboon viper, an efficient sunlight absorbability and water evaporation system has been developed by biomimetic snake-scale-like porous carbon (BSPC) from the carbonization of polycarbonate (PC) waste by ZnO. ZnO catalyzes the de-carboxylation of PC to form numerous micropores that act as porogens to introduce plenty of mesopores and macropores. Owing to the 3D interconnected hierarchical nanopores and rich oxygen-containing functional groups, the as-prepared BSPC exhibits high solar absorption (ca. 95%), low thermal conductivity (0.086 W m⁻¹ K⁻¹), superhydrophilicity, and superwettability. The combined merits endow BSPC with high solar-to-thermal conversion efficiency and fast water molecule transportation, and enable BSPC to demonstrate distinguished performance in interfacial solar-driven vapor generation. For instance, BSPC displays an evaporation rate of 1.58 kg m⁻² h⁻¹ under 1 kW m⁻², conversion efficiency of 91%, and metallic ion/dye removal efficiency of over 99.99%, making it among the best carbon-based solar evaporators reported so far. This work provides a new opportunity for water purification by the fusion of bioinspired solar evaporation systems and sustainable carbon materials with well-defined microstructures.