Nanofluidic channels inspired by electric eels open a new era of efficient harvesting of clean blue osmotic energy from salinity gradients. Limited by less charge and weak ion selectivity of the raw material itself, energy conversion through nanofluidic channels is still facing considerable challenges. Here, a facile and efficient strategy to enhance osmotic energy harvesting based on drastically increasing surface charge density of MXenes subnanochannels via oxygen plasma is proposed. This plasma could break Ti–C bonds in the MXenes subnanochannels and effectively facilitate the formation of more Ti–O, C═O, O–OH, and rutile with a stronger negative charge and work function, which leads the surface potential of MXenes membrane to increase from 205 to 430 mV. This significant rise of surface charge endows the MXenes membrane with high cation selectivity, which could make the output power density of the MXenes membrane increase by 248.2%, reaching a high value of 5.92 W m⁻² in the artificial sea-river water system. Furthermore, with the assistance of low-quality heat at 50°C, the osmotic power is enhanced to an ultrahigh value of 9.68 W m⁻², which outperforms those of the state-of-the-art two-dimensional (2D) nanochannel membranes. This exciting breakthrough demonstrates the enormous potential of the facile plasma-treated 2D membranes for osmotic energy harvesting.

中文翻译：

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用于高性能渗透能转换的等离子体氧化 2D MXenes 亚纳米通道膜

受电鳗启发的纳米流体通道开启了从盐度梯度中高效收集清洁蓝色渗透能的新时代。受限于原料本身电荷少、离子选择性弱，通过纳米流体通道进行能量转换仍面临相当大的挑战。在这里，提出了一种基于通过氧等离子体大幅增加 MXenes 亚纳米通道表面电荷密度的增强渗透能量收集的简便有效的策略。这种等离子体可以破坏MXenes亚纳米通道中的Ti-C键，有效促进更多Ti-O、C=O、O-OH和金红石的形成，这些Ti-O、C=O、O-OH和金红石具有更强的负电荷和功函数，从而导致MXenes膜的表面电势升高从 205 增加到 430 mV。表面电荷的显着增加赋予了MXenes膜高阳离子选择性，这可以使MXenes膜的输出功率密度增加248.2%，在人工海河水系统中达到5.92 W m ^{-2的高值。}此外，在50°C低质量热量的帮助下，渗透力增强至9.68 W m ^-2的超高值，优于最先进的二维（2D）纳米通道膜。这一令人兴奋的突破证明了易于等离子体处理的二维膜在渗透能量收集方面的巨大潜力。