Seeking an efficient and robust evaporator is the central goal of solar-driven interfacial steam generation. Here, a free-standing Janus aerogel with rough hydrophobic upper layer and smooth hydrophilic bottom layer was tailored by freeze drying of polypyrrole-polyvinyl alcohol (PPy/PVA) colloidal solution, followed by acetalization treatment and selective fluorination decoration. PPy/PVA-F Janus aerogel has a structure integrated in the form of different microscopic layers and chemical compositions, endowing it with omnidirectional light absorption, stable floating on water, enhanced evaporation performance, and salt rejection capability. Due to the reduced vaporization enthalpy, evaporation rate of 1.68 kg·m⁻²·h⁻¹ with solar-to-vapor efficiency of 94.7% was obtained under 1-sun irradiation using the Janus aerogel. Furthermore, the Janus aerogel demonstrated good recyclability and long-term durability at different radiation intensities. This Janus aerogel had satisfactory availability for solar desalination and sewage treatment. The strategy to integrate different microscopic layers and chemical compositions in a Janus aerogel holds great promise for the design and application of Janus evaporators in the field of solar steam generation.

寻求高效且坚固的蒸发器是太阳能驱动界面蒸汽发电的核心目标。在这里，通过冷冻干燥聚吡咯 - 聚乙烯醇（PPy / PVA）胶体溶液，然后进行缩醛化处理和选择性氟化装饰，定制了具有粗糙疏水上层和光滑亲水底层的独立 Janus 气凝胶。PPy/PVA-F Janus气凝胶具有以不同微观层和化学成分的形式集成的结构，赋予其全方位吸光、稳定漂浮在水面上、增强蒸发性能和脱盐能力。由于蒸发焓降低，蒸发率为1.68 kg·m ^-2 ·h ^-1使用 Janus 气凝胶在 1-sun 照射下获得了 94.7% 的太阳能 - 蒸汽效率。此外，Janus 气凝胶在不同辐射强度下表现出良好的可回收性和长期耐用性。这种 Janus 气凝胶在太阳能海水淡化和污水处理方面具有令人满意的可用性。在 Janus 气凝胶中整合不同微观层和化学成分的策略为 Janus 蒸发器在太阳能蒸汽发电领域的设计和应用提供了广阔的前景。