Author(s): Cai, X (Cai, Xu); Xiao, Y (Xiao, Yu); Zhang, BW (Zhang, Bingwen); Yang, YH (Yang, Yanhui); Wang, J (Wang, Jun); Chen, HM (Chen, Huamin); Shen, GZ (Shen, Guozhen)

Source: ADVANCED FUNCTIONAL MATERIALS DOI: 10.1002/adfm.202304456  Early Access Date: JUL 2023  

Abstract: MXene materials emerge as promising candidates for energy harvesting and storage application. In this study, the effect of the surface chemistry on the work function of MXenes, which determines the performance of MXene-based triboelectric nanogenerator (TENG), is elucidated. First-principles calculations reveal that the surface functional group greatly influences MXene work function: -OH termination reduces the work function with respect to that of bare surface, while -F and -Cl increase it. Then, work functions are experimentally determined by Kelvin probe force microscopy. The MXene prepared by gentle etching at 40 & DEG;C for 48 h (GE(40/48)) has the largest work function. Furthermore, an electron-cloud potential-well model is established to explain the mechanism of electron emission-dominated charge transfer and assemble a triboelectric device to verify experimentally its conclusions. It is found that GE(40/48) has the best performance with a 281 V open-circuit voltage, 9.7 & mu;A short-current current, and storing 1.019 & mu;C of charge, which is consistent with the model. Last, a patterned TENG is demonstrated for self-powered human-machine interaction application. This finding enhances the understanding of the inherent mechanism between the surface structure and the output performance of MXene-based TENG, which can be applied to other TENG based on 2D materials.

Accession Number: WOS:001019890000001

ISSN: 1616-301X

eISSN: 1616-3028