Natural wood-derived all-carbon-conductive foam for sustainable all-weather monolithic photo-electrothermal interfacial water evaporation

Interfacial solar evaporator (ISE) is a very promising low-carbon technology for producing fresh water. However, the evaporation rate of ISE is highly dependent on sunlight. Although various photo-electrothermal evaporators have been developed for all-weather steam generation, almost all of these materials are synthetic and environmentally unfriendly. Here, a natural wood-derived all-carbon conductive foam (ACCF) without adding any synthetic material is prepared by a top-down method as an all-weather monolithic photo-electrothermal evaporator. An ultrahigh temperature of 145.2 °C is reached with only a 2 V input voltage in a dry state due to its outstanding electrothermal effect. A remarkable evaporation rate of 2.25 kg/m2/h under 1 sun is achieved owing to its excellent photothermal conversion and reduced evaporation enthalpy, and it further increases to 6.73 kg/m2/h with a 2 V electrothermal compensation. The 3D cross-linked bimodal lumen and micro mesopores structures of the ACCF ensure rapid reflux of salt solution, which can realize long periods of no salt operation. More importantly, the ACCF can be degraded in the natural environment and will not cause secondary pollution of the water body. The remarkable advantages of ACCF include outstanding conductivity, excellent solar absorption, and environmental sustainability, making it a strong candidate for all-weather photo-electrothermal steam generation.