An important reason that restricts the evaporation rate of the solar-to-steam generator is the imbalance of water supply and demand in the solar absorber. Herein, a porosity-tunable evaporator (PTE) with submillimeter pores was introduced to accelerate water evaporation in terms of controlling the water supply velocity in the evaporation thin layer. The PTEs were composed of nanocarbon for light-absorbing and porous crosslinked polyvinyl alcohol for water supplying. The well-tailored apertures of PTE ensured adequate water supply velocity during evaporation, while excessive accumulation of water on the evaporation surface was prevented as a result of the dense skeleton of the upper surface layer. By adjusting the porosity and capillary height of PTE, a moderate water supply velocity was obtained. As a result, we received an evaporation rate of 1.67 kg m⁻² h⁻¹ under one sun illumination, which is the highest record so far for solar absorbers with submillimeter apertures. In addition, a long-term operation of PTE in 25% (w/w) NaCl solution showed an evaporation rate fluctuating around 1.59 kg m⁻² h⁻¹ within 3 h illumination, and maintaining to 1.34 kg m⁻² h⁻¹ after 6 h illumination. Having the advantages of controllable water supply velocity, fast evaporation rate, good salt resistance, together with its biocompatibility, acceptable cost (~58 $ m⁻²), and easy fabrication, PTE shows great potentials for its applications in the sustainable clean water production technologies.

限制太阳能蒸汽发生器蒸发速率的重要原因是太阳能吸收器中水的供需不平衡。在本文中，引入了具有亚毫米孔的孔隙度可调蒸发器（PTE），以控制蒸发薄层中的供水速度来加速水的蒸发。PTE由用于吸收光的纳米碳和用于供水的多孔交联聚乙烯醇组成。精心设计的PTE孔确保了蒸发过程中足够的供水速度，同时由于上表层的致密骨架，防止了水在蒸发表面上的过多积聚。通过调节PTE的孔隙率和毛细管高度，可获得适中的供水​​速度。结果，我们得到的蒸发率为1。在一个阳光照射下^-2  h ^-1，这是迄今为止具有亚毫米孔径的太阳能吸收器的最高记录。此外，PTE在25％（w / w）NaCl溶液中的长期运行显示，蒸发速率在3 h照射下的蒸发速率在1.59 kg m ^-2  h ^-1左右波动，并保持在1.34 kg m ^-2  h ^-1照明6小时后。PTE具有可控制的供水速度，快速的蒸发速度，良好的耐盐性以及其生物相容性，可接受的成本（〜58 $ m ⁻²）和易于制造的优点，在其可持续的清洁水生产中显示出巨大的应用潜力技术。