Nanofluidics is the system of fluid transport limited to nano-confined space, including the transport of ions and molecules. The use of intelligent nanofluidics have shown great potential in energy conversion. However, ion transport is hindered by homogeneous membranes with uniform charge distribution and concentration polarization, which often leads to an undesirable power conversion performance. Here, we demonstrate the feasibility of neutralization reaction-enhanced energy conversion process based on the heterogeneous graphene oxide (GO) nanofluidics with bipolar structure. The asymmetric charge distribution inherent to this heterogeneous nanofluidics facilitate a complementary two-way ion diffusion process, which in turn promotes efficient charge separation and superposed ionic diffusion. An output power density of up to 29.58 W·m-2 is achieved with 0.1 M HCl/NaOH as the acid-base pair (ABP), which is about 712% and 117% higher than using symmetric unipolar pGO and nGO membranes. Both experiments and theoretical simulations indicate that the tunable asymmetric heterostructure contributes to regulating diffusion-based ion transport and enhancing the ion flux. This work not only establishes a significant paradigm for the utilization of chemical reactions within nanofluidic systems but also opens up new avenues for groundbreaking discoveries in the fields of chemistry, nanotechnology, and materials science.

中文翻译：

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通过异相氧化石墨烯膜从中和反应中收集离子能


纳米流体是仅限于纳米受限空间的流体传输系统，包括离子和分子的传输。智能纳米流体的使用在能量转换方面显示出巨大的潜力。然而，具有均匀电荷分布和浓度极化的均相膜会阻碍离子传输，这通常会导致不理想的功率转换性能。在这里，我们展示了基于具有双极结构的异质氧化石墨烯 （GO） 纳米流体的中和反应增强能量转换过程的可行性。这种非均相纳米流体固有的不对称电荷分布促进了互补的双向离子扩散过程，这反过来又促进了有效的电荷分离和叠加离子扩散。使用 0.1 M HCl/NaOH 作为酸碱对 （ABP） 可实现高达 29.58 W·m-2 的输出功率密度，比使用对称单极 pGO 和 nGO 膜高约 712% 和 117%。实验和理论模拟都表明，可调谐的不对称异质结构有助于调节基于扩散的离子传输和增强离子通量。这项工作不仅为纳米流体系统中化学反应的利用建立了重要的范式，而且还为化学、纳米技术和材料科学领域的突破性发现开辟了新的途径。