Innovative materials are required to promote the development of solar-powered interfacial desalination and purification technologies to address global freshwater scarcities. To this end, evaporators using polymeric hydrogels have been widely studied. However, these systems are slow, energy-intensive, complex, and difficult to operate. New strategies are in urgent need. The present work employs polymeric phase inversion to develop poly (vinyl alcohol) (PVA)-based foam hydrogels, wherein the air bubble phase served as the matrix and cross-linked PVA hydrogel acted as the dispersed phase. In addition, we utilize Ti₃C₂T_x nanosheets-based MXene as the photothermal agent to facilitate the fabrication of hierarchical pore-in-pore structures. The prepared PVA/MXene foam hydrogels exhibit > 95% porosity, as well as high compressibility (>7000 cycles) and very rapid water transport. Importantly, these materials also exhibit remarkably low water evaporation enthalpies. Combined with a new heat supply model, those foam hydrogels achieve an evaporation rate of 4.1 ± 0.1 kg m⁻²h⁻¹ with energy efficiency up to 128.8% ± 2.0% under 1 sun irradiation, which is the highest value for MXene-based nanocomposites reported so far. This study demonstrates a significant advancement in solar desalination system by combining phase inversion to make innovative foam materials with optimal external heat management.

需要创新材料来促进太阳能界面海水淡化和净化技术的发展，以解决全球淡水资源短缺问题。为此，已经广泛研究了使用聚合物水凝胶的蒸发器。然而，这些系统速度慢、耗能大、复杂且难以操作。迫切需要新的战略。目前的工作采用聚合物相转化来开发聚（乙烯醇）（PVA）基泡沫水凝胶，其中气泡相作为基质，交联 PVA 水凝胶作为分散相。此外，我们利用 Ti ₃ C ₂ T _x基于纳米片的 MXene 作为光热剂，以促进分层孔中孔结构的制造。制备的 PVA/MXene 泡沫水凝胶具有 > 95% 的孔隙率、高压缩性（>7000 次循环）和非常快速的水传输。重要的是，这些材料还表现出非常低的水蒸发焓。结合新的供热模型，这些泡沫水凝胶在 1 次太阳照射下的蒸发率为 4.1 ± 0.1 kg m ⁻² h ⁻¹，能量效率高达 128.8% ± 2.0%，这是基于 MXene 的最高值迄今为止报道的纳米复合材料。这项研究通过结合相转化来制造具有最佳外部热管理的创新泡沫材料，展示了太阳能海水淡化系统的重大进步。