Solar steam generation is an emerging research field to approach the challenge of water shortages all around the world. Abundant light absorber materials have been developed to improve the broadband absorption of sunlight in the past few years, but the thermal insulating layers that often make a significant improvement in the photothermal conversion performance of the device have rarely been researched. A material that has both excellent heat insulation property and high light absorption is also uncommon. Bioinspired by the hollow hair of polar bears, here we demonstrate difunctional carbon-nanotube-based aerogels (DCTAs), which not only can be used as the thermal insulating layer that helps to resist heat loss from the surface to bulk water but also serve as the absorber layer. The hollow carbon nanofiber network structure can effectively resist thermal transport so that the carbon-nanotube-based aerogel shows great thermal insulating properties. Besides, the aerogel can self-float on the surface of water because of its lightweight and hydrophobic nature. By further compositing with Au nanoparticles, the broadband absorption of aerogel is up to 98% in the wavelength range of 250–2000 nm. This rational design endows the DCTAs with a good solar thermal conversion performance.

中文翻译：

---

仿生双功能碳纳米管气凝胶，可高效产生蒸汽

太阳能蒸汽发电是一个新兴的研究领域，旨在应对世界各地水资源短缺的挑战。在过去的几年中，已经开发出大量的吸光材料来改善对阳光的宽带吸收，但是很少对经常显着改善器件的光热转换性能的绝热层进行研究。具有优异的隔热性能和高的光吸收率的材料也是罕见的。受北极熊空心发丝的生物启发，我们在此展示了基于碳纳米管的双功能气凝胶（DCTA），该气凝胶不仅可用作隔热层，有助于抵抗从表面到大量水的热损失，而且还可以用作吸收层。中空的碳纳米纤维网络结构可以有效地抵抗热传输，从而使碳纳米管基气凝胶具有出色的隔热性能。此外，气凝胶由于其轻质和疏水性而可以在水表面自漂浮。通过与Au纳米颗粒进一步复合，气凝胶在250–2000 nm波长范围内的宽带吸收率高达98％。这种合理的设计使DCTA具有良好的太阳热转换性能。