3D porous N-doped lignosulfonate/graphene oxide aerogel for efficient solar steam generation and desalination

Solar-driven interfacial evaporation has been considered one of the most promising approaches to tackle the issue of water scarcity. The salt resistance and water transport capacity of solar evaporation materials are essential to evaluate desalination performance. Herein, a 3D-porous N-doped lignosulfonate/graphene oxide (GO) aerogel (NLGA) was facilely prepared by a one-step hydrothermal method. By introducing ethylenediamine (EDA) as a nitrogen source, the wettability and water transport capacity of the aerogel were enhanced; by introducing lignosulfonate (LS), its porous structure was regulated, and its light absorption capability was significantly improved. The obtained aerogel exhibited an outstanding evaporation rate (1.57 kg m- 2 h-1) and efficiency (95.2 %) under 1 sun illumination, which is significantly better than some reported foam-based solar evaporators. In addition, NLGA maintained a stable evaporation rate over long-term cyclic evaporation without visible salt accumulation on the surface. The good salt rejection performance is due to the rich-pore structure and superhydrophilicity of NGLA, which provides sufficient water supply to dissolve the salts during water evapo-ration. NLGA has enormous potential as a solar evaporator based on its excellent performance in solar vapor generation.

Automated summary

Solar-driven interfacial evaporation is a promising approach to address water scarcity. A 3D-porous N-doped lignosulfonate/graphene oxide aerogel (NLGA) was prepared by a one-step hydrothermal method. The NLGA showed excellent evaporation rate and efficiency under 1 sun illumination, surpassing foam-based solar evaporators. It also maintained stable evaporation rate without salt accumulation due to its rich-pore structure and superhydrophilicity.