Laser-engraved wood-based evaporators: A sustainable approach for solar interfacial evaporation

Solar interfacial evaporation is recognizable as one of the most prospective strategies to overcome the shortage of fresh water. Recently, there has been growing enthusiasm for the development of wood-based evaporators for solar steam generation. Although such technologies as surface coating and carbonization have been developed, it remains a challenge to cost-effectively manufacture high-efficient wood evaporators under open conditions with long-term serviceability. Here, a generalized laser engraving-driven integrated approach is proposed for simultaneously achieving the conversion of the surface of wood with chelation treatment to carbon and metal oxides and the construction of surface architectures in open environments, resulting in unique stabilized efficient wood-based evaporators. Thanks to the exceptional photothermal conversion properties and stability of carbon and metal oxides, as well as the efficient water transport and the inhibition of dense crystallized salts by the patterned surface structure, the fabricated evaporator exhibits a remarkably more efficient and stabilized output, with evaporation and retention rates of ∼1.72 kg m–2 h−1 and ∼93 %, respectively, surpassing the pristine wood with enhancements of ∼100 % and 120 %, respectively. More impressively, the applicability can be extended to other metal chelates. This work presents a new and sustainable strategy for the development of solar interfacial evaporators utilizing biomass materials.