Hierarchically porous nickel foam supported Co-NCNT arrays for efficient solar water evaporation, wastewater purification and electricity generation

Developing advanced solar-powered interfacial evaporators with three-dimensional porous configuration inte-grating key components of effective solar conversion, adequate water transmission, and flexible thermal mod-ulation is highly demanded but remains a major challenge for solar steam generation. In this work, nitrogen -doped carbon nanotube@Co arrays are in situ grown on three-dimensional macroporous nickel foam (Co-NCNT/NF) to act as a hierarchically porous configuration for solar water evaporation. Synergistic cooperation between Co nanoparticles and NCNT leads to outstanding broadband absorption across whole solar spectrum. Under 1 sun irradiation, the Co-NCNT/NF can rapidly respond to solar light and generate a stable surface temperature as high as 41.5 degrees C during solar evaporation process. Benefiting from the multifunctional structure features, the Co-NCNT/NF achieves a high evaporation rate of 1.65 kg m(- 2) h(-1) and an evaporation efficiency up to 97.5 % under 1 sun irradiation. Such performance facilitates the continuous production of clean water from seawater and the effective purification of various wastewater. Moreover, comprehensive utilization of additional heat loss during solar water evaporation for thermoelectric power generation is demonstrated as well.

Automated summary

This study developed an advanced solar-powered interfacial evaporator with a three-dimensional porous configuration that effectively converts solar energy into steam. By using nitrogen-doped carbon nanotube@cobalt arrays, the evaporator achieved outstanding broadband absorption across the entire solar spectrum. Under 1 sun irradiation, the evaporator rapidly responded to solar light and generated a stable surface temperature, resulting in high evaporation rate and efficiency. This performance facilitates the continuous production of clean water, effective purification of wastewater, and utilization of additional heat loss for thermoelectric power generation.