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. (Figure presented.)