Surface termination modification on high-conductivity MXene film for energy conversion

Two-dimensional transition metal carbides and nitrides (MXenes) demonstrate excellent performances in various field as a result of their unique surface group structures and high electrical conductivity. In this work, we employ a simple strategy of surface group modification to optimize the semiconductor performance of a high-conductivity Ti3C2Tx film for thermoelectric energy conversion. In the process, the hydrothermal treatment with different concentrations, temperatures, and types of alkali solutions has significant effects on the thermoelectric properties of Ti3C2Tx. As a result, the modified free-standing Ti3C2Tx film maintained its originally high conductivity (1652 S cm−1) and the Seebeck coefficient is improved threefold, leading to an optimized power factor of 44.98 μW m−1K−2 at room temperature. This study provides a new method for the development of the thermoelectric performance of highly-conductive MXene films.