Effect of two-dimensional MXene on electrical conductivity of cement pastes

Abstract

In this study, two-dimensional (2D) MXene cement-based material with high electrical conductivity was prepared. The conductive behavior of cement pastes was measured by electrochemical impedance spectroscopy (EIS) and four-probe method. Besides, the microstructures of cement pastes were examined by scanning electron microscope (SEM), X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP). The results demonstrate that the variation of electrical conductivity corresponds to percolation theory, and curing age exerts a negligible influence on the percolation threshold. Increasing the MXene content leads to both an increase in the electrical conductivity and the compressive strength (at an MXene dosage below 0.5 wt%). SEM analysis reveals that MXene can form a conductive network in the percolation zone of the matrix. Moreover, the hydration degree is promoted with the addition of MXene within 1.0 wt%, reflected by XRD analysis. The MIP results demonstrate that the addition of MXene at 0.7 wt% significantly reduces the porosity.