Efficient light absorption and trapping are of vital importance for the solar water evaporation by hydrogel-based photothermal conversion materials. Conventional strategies are focused on the development of the composition and structure of the hydrogel's internal network. In our point of view, the importance of the surface structure of hydrogel has usually been underestimated or ignored. Here inspired by the excellent absorbance and water transportation ability of biological surface structure, the hierarchical structured hydrogel evaporators (HSEs) increased the light absorption, trapping, water transportation and water-air interface, which is the beneficial photothermal conversion and water evaporation. The HSEs showed a rapid evaporation rate of 1.77 kg·m^-2·h^-1 at about 92% energy efficiency under one sun (1 kW·m^-2). Furthermore, the superhydrophilic window device was used in this work to collect the condensed water, which avoids the light-blocking caused by the water mist formed by the small droplets and the problem of the droplets stick on the device dropping back to the bulk water. Integrated with the excellent photothermal conversion hydrogel and superhydrophilic window equipment, this work provides efficient evaporation and desalination of hydrogel-based solar evaporators in practical large-scale applications.

有效的光吸收和捕集对于通过基于水凝胶的光热转换材料蒸发太阳能水至关重要。常规策略集中于水凝胶内部网络的组成和结构的发展。在我们看来，水凝胶表面结构的重要性通常被低估或忽略。在此，受到生物表面结构优异的吸收和输水能力的启发，分层结构的水凝胶蒸发器（HSE）增加了光吸收，捕集，输水和水-空气界面，这是有益的光热转换和水蒸发。HSEs的快速蒸发速率为1.77 kg·m ^-2 ·h ^-1在1个太阳（1 kW·m ^-2）下能效约为92％。此外，在这项工作中使用了超亲水的窗户装置来收集冷凝水，避免了由小液滴形成的水雾引起的遮光，以及避免了液滴粘附在装置上滴落回大量水的问题。结合出色的光热转化水凝胶和超亲水性窗户设备，这项工作可在实际的大规模应用中对基于水凝胶的太阳能蒸发器进行有效的蒸发和脱盐。