Harvesting solar energy with a Ni-MOF-based evaporator for efficient solar thermal storage and steam generation

Harvesting solar energy for efficient photothermal conversion and steam generation over solar evaporators is particularly significant in the context of comprehensive solar utilization toward solving the global shortage of fresh water. Herein, a flexible Ni-based metal-organic framework composite (NMC) with hierarchical structures is constructed as a photothermal material for solar steam-generation devices. Besides, a phase change material (PCM)-based thermal storage pack is incorporated into the solar evaporator to overcome the solar radiation intermittency. By virtue of the synergistic effect of the promising 3D structure and excellent water transport, the NMC-PCM evaporator possesses an outstanding evaporation performance (2.55 kg m −2 h −1 ) under 1 sun irradiation. More strikingly, owing to the enhanced light-to-heat performance as well as large heat storage capacity, the proposed evaporator achieves a high water-evaporation rate of 1.46 kg m −2 h −1 without sunlight irradiation. This work opens up opportunities to realize excellent energy capture for solar-driven clean water production and solar thermal storage not only under sunlight incidence but also in no light environment. A hybrid solar evaporator comprising a Ni-based metal-organic framework material and a phase change material composite was fabricated for high performance solar-thermal energy storage and continuous solar vapor generation.