Spray-freezing induced multidimensional morphology tuning of assembled spherical carbon for solar-driven steam generation

Spray-freezing induced multidimensional morphology tuning of assembled spherical carbon for solar-driven steam generation

Da Li, Ang Li, Yaxin Chen, Guanyu Chen, Xiaohong Chen, Dexu Zhang, Haitao Zhu, Imran Ahmed Samo, Huaihe Song

Abstract

Carbon materials have been extensively researched as solar absorbers in the field of solar steam generation (SSG) for their full spectrum absorption, non-biotoxicity, and excellent photothermal properties. In this work, we provide a general ice-templating method for obtaining multidimensional carbon materials controlled by regulating the surface tension during the phase separation of phenolic resin solution. Through spraying the atomized droplets into liquid nitrogen, freeze drying, and carbonization, a type of spherical carbon material assembled with carbon nanosheets with a thickness of about 3 nm can be obtained. With the enhancement of the surface tension by spray and the adjustment of the concentration of phenolic resin, a series of morphologies of carbon materials can be obtained from nanowires to nanosheets and further to spherical assemblies. In addition, an efficient SSG system was designed by combining the carbon material with polyurethane foam as matrix, notably showing good evaporation efficiency of 81.7% with a solar flux of 500 W/m2. This work provides a new idea for the morphology control of assembled carbon materials and has achieved excellent performance in the field of photothermal conversion.

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