Solvothermal-induced (002) facet orientation in multi-layer Ti3C2Tx MXenes: a facet engineering approach for enhanced capacitive performance

MXenes are considered ideal electrode materials. However, the cumbersome and poorly efficient preparation of few-layer MXenes, whereas the electrochemical performance of the more easily producible multi-layer MXenes is fundamentally constrained by severe interlayer stacking. In this work, the (002) facet orientation of multi-layer Ti 3 C 2 T x was modified via a solvothermal process, resulting in substantially enhanced electrochemical properties. The texture coefficients of (002) facet (TC (002) ) in multi-layer Ti 3 C 2 T x increases with increasing solvothermal temperature. Moreover, the specific capacitance was calculated to be approximately proportional to TC (002) , and HMX-180 reached a capacity of 310.2 F g −1 at a current density of 1 A g −1 . Density functional theory (DFT) calculations revealed that the (002) facets have the minimum adsorption energy for H + and a higher Fermi energy level, indicating that the (002) facets are more likely to be enriched with H + and exhibit higher electrical conductivity. These features promote the rapid transport of H + between the Ti 3 C 2 T x layers. Furthermore, multi-layer Ti 3 C 2 T x prepared via MILD method also undergoes (002) facet orientation and corresponding performance enhancement through this approach. This work provides a universal and scalable approach for fabricating high-performance MXene electrodes, which holds considerable promise for developing next-generation supercapacitors for practical applications in portable electronics and sustainable energy systems. This strategy also offers considerable potential for application in other energy storage systems, including metal-ion batteries, and catalytic devices.