HF-free synthesis of high-entropy MXene-PVA composite film and its flexible nanogenerator

Abstract

MXene exhibits notable piezoelectric properties, making it a promising material for high-performance piezoelectric nanogenerators (PENGs) in next-generation smart wearable devices and bioelectronics. However, current MXene-based PENGs face challenges such as insufficient mechanical robustness, low piezoelectric response, and limited long-term functionality. These limitations primarily stem from the small effective area and low strain levels of MXene nanosheets. Here, we constructed a high-entropy TiVCrMoC3Tx MXene composite film by leveraging strong hydrogen bonding interactions between MXene and polyvinyl alcohol (PVA), which was further developed into a self-powered flexible nanogenerator. The resulting device exhibited a significant piezoresponse with output signals of 500 mV and 790 pA under a compressive force of 3.47 N, along with considerable long-term functionality over 1500 cycles. Moreover, a hydrofluoric-free etching approach was employed to synthesize the high-entropy MXene nanosheets, which ensures the safety and biocompatibility for bioelectronics applications. This work highlights the potential of high-entropy MXene for sustainable applications in wearable electronics and energy harvesting. MXene表现出显著的压电性能, 使其成为下一代智能可穿戴设 备和生物电子学中高性能压电纳米发电机(PENGs)应用的潜力材料. 然而, 当前基于MXene的压电纳米发电机面临诸多挑战, 例如机械强度 不足、压电响应较低以及长期工作稳定性有限. 这些问题主要源于 MXene纳米片的有效应力传递面积较小以及应变水平较低. 在本研究 中, 我们通过利用MXene与聚乙烯醇(PVA)之间的强氢键相互作用, 构建了一种高熵TiVCrMoC3Tx MXene复合薄膜, 并进一步开发出一种 自供电柔性纳米发电机. 该器件在受到3.47 N的压力时输出高达 500 mV和790 pA的压电信号, 且在1500个循环工作过程中表现出良好 的长期工作稳定性. 此外, 该高熵MXene纳米片通过无氢氟酸(HF-free) 蚀刻方法合成, 确保了其在生物电子学应用中的安全性和生物相容性. 本工作突显了高熵MXene在柔性可穿戴电子产品和能量收集方面的可 持续应用潜力.