Harvesting environment energy from water-evaporation over free-standing graphene oxide sponges
Harvesting environment energy from water-evaporation over free-standing graphene oxide sponges
复制标题
通过独立式氧化石墨烯海绵的水蒸发收集环境能量
DOI：
10.1016/j.carbon.2019.03.041
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发表时间：
2019-07-01
期刊：
影响因子：
10.9
通讯作者：
Yao, Wei
中科院分区：
文献类型：
--
作者：
Zhang, Guang;Duan, Zheng;Yao, Wei
由于全球能源需求的增加、环境污染以及自供电设备的快速发展，将无处不在的环境能源转化为可用能源（例如电力）正在引起全世界越来越多的关注。在此，使用冷冻干燥方法制造了一种多孔氧化石墨烯（GO）海绵。然后进行退火处理和UV + O-3氧化以获得部分还原的GO（rGO）海绵。我们发现这些 rGO 海绵可以通过水的自然蒸发将环境能量转化为电能。经测量，单块 rGO 海绵产生的开路电压高达约 0.63 V。计算出最大输出功率和输出功率密度分别约为17.30μW和1.74μW·cm(-2)。我们认为，由水分子-石墨烯相互作用产生的流动电势应该是水蒸发诱导发电的基本机制。此外，我们证明环境温度、气流速度和蒸发面积都会严重影响发电。此外，通过串联多个样品，水蒸发感应电压可以轻松放大至约 2.34 V。因此，我们的工作提供了一种将无处不在的环境能源转化为电能的潜在方法。 (C) 2019 Elsevier Ltd. 保留所有权利。
Due to increasing global energy demands, environmental pollution, and the rapid development of self-powered devices, converting ubiquitous environmental energy to usable energy, e.g., electricity is attracting increasing interests worldwide. Herein, a type of porous graphene oxide (GO) sponges is fabricated using the freeze-drying method. Then an annealing treatment and UV + O-3 oxidation are carried out to achieve partially reduced GO (rGO) sponges. We find that these rGO sponges can convert environmental energy to electricity via the natural evaporation of water. The generated open-circuit voltages are measured to be as high as about 0.63 V over a single piece of rGO sponges. The maximum output power and output power density are calculated to be approximately 17.30 mu W and 1.74 mu W cm(-2), respectively. We suggest that streaming potentials, which arise from water molecule-graphene interactions, should be the underlying mechanism of water-evaporation-induced electricity generation. Furthermore, we demonstrate that ambient temperatures, airflow velocities, and evaporation-areas all can seriously influence the electricity generation. Moreover, the water-evaporation-induced voltage can be easily scaled up to as high as about 2.34 V by connecting multiple samples in series. Therefore, our work supplies a potential method of converting ubiquitous environmental energy to electricity. (C) 2019 Elsevier Ltd. All rights reserved.