Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Nat Nanotechnol. 2017 May;12(4):317-321. doi: 10.1038/nnano.2016.300. Epub 2017 Jan 30.
Water evaporation is a ubiquitous natural process that harvests thermal energy from the ambient environment. It has previously been utilized in a number of applications including the synthesis of nanostructures and the creation of energy-harvesting devices. Here, we show that water evaporation from the surface of a variety of nanostructured carbon materials can be used to generate electricity. We find that evaporation from centimetre-sized carbon black sheets can reliably generate sustained voltages of up to 1 V under ambient conditions. The interaction between the water molecules and the carbon layers and moreover evaporation-induced water flow within the porous carbon sheets are thought to be key to the voltage generation. This approach to electricity generation is related to the traditional streaming potential, which relies on driving ionic solutions through narrow gaps, and the recently reported method of moving ionic solutions across graphene surfaces, but as it exploits the natural process of evaporation and uses cheap carbon black it could offer advantages in the development of practical devices.
水蒸发是一种普遍存在的自然过程，它从环境中获取热能。它已经在许多应用中得到了利用，包括纳米结构的合成和能量收集器件的制造。在这里，我们表明，从各种纳米结构碳材料的表面蒸发水可以用来发电。我们发现，在环境条件下，从厘米大小的碳黑片上蒸发可以可靠地产生高达 1 V 的持续电压。水分子与碳层之间的相互作用，以及蒸发诱导的多孔碳片中的水流，被认为是产生电压的关键。这种发电方法与传统的流动电势有关，流动电势依赖于将离子溶液驱动通过狭窄的间隙，以及最近报道的在石墨烯表面移动离子溶液的方法，但由于它利用了蒸发的自然过程，并使用了廉价的碳黑，因此在开发实用器件方面可能具有优势。
