Gaseous Scissor-mediated Electrochemical Exfoliation of Halogenated MXenes and its Boosting in Wear-Resisting Tribovoltaic Devices

TL;DR

This paper introduces a novel gaseous scissor-mediated electrochemical exfoliation method to produce few-layer halogenated MXenes, significantly improving their yield and surface chemistry control for enhanced tribovoltaic device performance.

Contribution

The study presents an innovative electrochemical exfoliation technique using gaseous scissors to efficiently produce high-yield, surface-chemistry-preserved MXene nanosheets for electronic applications.

Findings

Achieved ~93% yield of few-layer MXenes

Demonstrated improved electrical output in tribovoltaic nanogenerators

Enabled better understanding of MXenes' physical properties

Abstract

Two-dimensional transition metal carbides (MXenes), especially their few-layered nanosheets, have triggered burgeoning research attentions owing to their superiorities including extraordinary conductivity, accessible active surface, and adjustable processability. Molten salts etching route further achieves their controllable surface chemistry. However, the method encounters challenges in achieving few-layer structures due to more complex delamination behaviors. Herein, we present an efficient strategy to fabricate Cl- or Br-terminated MXene nanoflakes with few-layers, achieved by electrochemical intercalation of Li ions and concomitant solvent molecules in the electrolyte solution, with gaseous scissors (propylene molecules) to break up interlayer forces. By controlling cut-off voltages, the optimal protocol results in nanosheets with an ultrahigh yield (~93%) and preserved surface chemistry. The resultant MXenes dispersions were employed as lubricants to enhance tribovoltaic nanogenerators, where Ti3C2Br2 displayed superior electrical output. These findings facilitate the understanding of MXenes' intrinsic physical properties and enable the nanoengineering of advanced electronic devices.