关键词: 碳纳米管, 三明治结构, 湿气发电, 水分吸附, 湿气传感

Abstract: Against the backdrop of growing demand for energy transformation and environmentally friendly technologies, moisture-electric generation can utilize the interaction of water molecules in the atmosphere (such as moisture and water vapor) with specific materials to generate electricity. It does not require complex configuration and has higher adaptability and stability. It is gradually being regarded as an important potential energy solution for flexible electronics, self-powered systems, and environmental sensing devices. In this paper, carbon nanotubes (CNTs) are used as the basic material to assemble the MWCNTs−COOH@CaCl2/PVA-H3PO4/CNT moisture-electric generator. MWCNTs−COOH@CaCl2 film and CNT film are prepared by ultrasonic dispersion and vacuum filtration, respectively, as the upper and lower electrodes of the device. Specifically, the carboxyl (−COOH) functional groups and hydrophilic material calcium chloride (CaCl2) in the upper electrode MWCNTs−COOH@CaCl2 film significantly enhance its hygroscopicity and form a good moisture enrichment interface. CaCl2 not only acts as a hygroscopic agent to promote the ionization of surface water to produce protons (H+), but also releases charged ions such as Ca2+, further enhancing the ion concentration gradient. The middle layer uses polyvinyl alcohol phosphoric acid (PVA-H3PO4) gel electrolyte with high proton conductivity to provide a continuous and stable channel for ion migration. The device constructs a variety of asymmetric characteristics: functional group distribution, electrode hydrophilicity, ion concentration and asymmetric water diffusion path, which synergistically enhance the power generation performance of the device. The study found that constructing an asymmetric sandwich structure with different hydrophilicity between the upper and lower electrodes helps to enhance the efficiency of ion migration under humidity gradient, thereby improving the overall electrical output performance of the device. The designed device shows good stability and adaptability under a variety of humidity environments and mechanical deformation conditions, and has the potential for flexible, wearable and self-powered applications. At the same time, the device can respond to dynamic moisture disturbances and show good humidity sensing capabilities, verifying its feasibility in small electronic power supply and physiological signal monitoring. In the future, the adaptability tests of the devices can be expanded in various practical scenarios, such as high-frequency dynamic humidity response and multi-point distributed sensing applications; combined with the development of integrated electronic systems, such devices can also be used in wearable health monitoring, flexible smart textiles and environmental perception platforms.

Key words: carbon nanotubes, sandwich structure, moisture power generation, moisture adsorption, moisture sensing