Dyson sphere-like evaporators enhanced interfacial solar evaporation via self-generated internal convection

Enhancing solar evaporation performance while minimizing material consumption is essential for advancing the practical application of interfacial solar evaporation technologies. Although introducing external airflow can significantly boost evaporation rates, it requires additional components and electricity input, compromising the simplicity, passivity and sustainability of interfacial solar evaporation. To address this challenge, Dyson sphere-like evaporators (DSEs) capable of self-generating convective flow inside the evaporator are designed. This self-generated internal airflow facilitates the removal of generated vapor from both inner and outer evaporation surfaces, thus significantly improving the evaporation rate. Notably, despite sacrificing 36% of solar light energy to generate internal convection, the DSE still achieves a much higher evaporation rate (4.08 kg m^-2 h^-1) compared to a typical spherical evaporator (2.04 kg m^-2 h^-1) which utilizes all the solar light energy directly for water evaporation. This finding suggests that future evaporator design should consider the balance between the energy used for water evaporation and convection generation for vapor removal.