Moist electric generators (MEGs) are promising portable power sources for harvesting energy from atmospheric moisture. However, the lack of an efficient device design and the associated working mechanisms related to ion interactions have resulted in relatively low electrical performance and short output times. In this study, we developed an efficient organic–inorganic hybrid MEG by in situ preparation of highly hygroscopic polyacrylamide ionic hydrogels on silicon nanowire arrays. The device yielded a record open-circuit voltage of 1.28 V at a relative humidity of 60% and 35 °C, and it maintained 60% of the peak performance even after 800 h of continuous operation. This exceeds the operating times of similar devices reported to date by a factor of approximately three. The outstanding performance achieved was due to the synergistic effect of the hybrid design: the increased dissociated ions from the ionic hydrogels, enhanced ion migration rate caused by the ion-induced Hofmeister effect, and rich cation-selective nanochannels of the robust silicon nanowires. More importantly, ions with smaller hydration radii and lower valence states can migrate faster within the nanochannels, thereby enhancing the electrical output of MEGs. This study provides a general ion-selection mechanism for improving the electrical output and operating time of MEGs.

中文翻译：

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基于硅纳米线/离子水凝胶的混合湿发电机，具有增强的电压输出和运行稳定性

潮湿发电机（MEG）是一种很有前途的便携式电源，用于从大气水分中获取能量。然而，缺乏有效的器件设计和与离子相互作用相关的工作机制导致了相对较低的电性能和较短的输出时间。在这项研究中，我们通过在硅纳米线阵列上原位制备高吸湿性聚丙烯酰胺离子水凝胶，开发了一种高效的有机-无机杂化MEG 。该器件在相对湿度 60% 和 35 °C 的条件下产生了 1.28 V 的创纪录开路电压，并且即使在连续运行 800 小时后仍保持 60% 的峰值性能。这比迄今为止报告的类似设备的运行时间高出大约三倍。所取得的出色性能归功于混合设计的协同效应：离子水凝胶中解离离子的增加、离子诱导的霍夫迈斯特效应引起的离子迁移速率的增强以及坚固的硅纳米线的丰富的阳离子选择性纳米通道。更重要的是，具有较小水合半径和较低价态的离子可以在纳米通道内更快地迁移，从而增强MEG的电输出。这项研究提供了一种通用的离子选择机制，用于提高 MEG 的电输出和运行时间。