Aging Effect on Ti3C2Tx MXene: A Morphological, Electronic, and Electrical Investigation

MXenes, the two-dimensional class of nanomaterials consisting of transition metal carbides, nitrides, or carbonitrides, have been spotlighted in the last decade due to their peculiar properties, allowing them to be applicable in different fields, ranging from energy storage to sensors. In particular, the Ti3C2Tx MXene phase has attracted attention for electronic and optoelectronic applications. In such fields, it is important to characterize the stability of this phase. Testing the stability of the aged sample may provide new hints for the engineering of this phase, ensuring its long-term performance. X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure measurements with a synchrotron source, complementary studies with a conventional X-ray source, and electrical conductivity measurements were employed to characterize the electronic and structural properties of a Ti3C2Tx thin film deposited on a quartz substrate immediately after preparation and again one year later, following storage in a nitrogen-filled environment. Despite only minor surface oxidation after one year, the conductivity of the aged sample decreased by nearly one order of magnitude compared to the as-prepared sample, highlighting the need for appropriate precautions if this MXene phase is to be implemented in electronic or optoelectronic devices.