All-weather-available electrothermal and solar–thermal wood-derived porous carbon-based steam generators for highly efficient water purification

Solar steam generation devices cannot work properly under weak solar light irradiation and even no solar light. Herein, all-weather-available electrothermal and solar–thermal wood-derived porous carbon-based water steam generation devices are fabricated for highly efficient water evaporation and purification by preparing wood-derived hydrophilic and porous carbon architectures, generating grooves on their top surfaces, and coating with hydrophobic layers of carbon nanoparticles. Under solar light irradiations, the eco-friendly wood-derived steam generation device can harvest solar energy efficiently for thermally evaporating water on the basis of its solar–thermal energy conversion mechanism. Under a weak solar light irradiation or even no solar light, the steam generator can still generate clean water via its electrothermal evaporation mechanism. Under 1-sun irradiation, the steam generator exhibits a water evaporation rate of 1.49 kg m−2 h−1 with an evaporation efficiency of 77.2%. By integrating the solar–thermal and electrothermal energy conversion mechanisms, an ultrahigh water evaporation rate of 11.73 kg m−2 h−1 is readily achieved under 1-sun irradiation with a voltage of 6 V. The integration of the electrothermal and solar–thermal energy conversion mechanisms makes the environmentally friendly carbon-based steam generator all-weather-available for generating sufficient clean water from wastewater and seawater.