The effect of the interlayer element on the exfoliation of layered Mo(2)AC (A = Al, Si, P, Ga, Ge, As or In) MAX phases into two-dimensional Mo(2)C nanosheets

The experimental exfoliation of layered, ternary transition-metal carbide and nitride compounds, known as MAX phases, into two-dimensional (2D) nanosheets, is a great development in the synthesis of novel low-dimensional inorganic systems. Among the MAX phases, Mo-containing ones might be considered as the source for obtaining Mo(2)C nanosheets with potentially unique properties, if they could be exfoliated. Here, by using a set of first-principles calculations, we discuss the effect of the interlayer ‘A’ element on the exfoliation of Mo(2)AC (A = Al, Si, P, Ga, Ge, As or In) MAX phases into the 2D Mo(2)C nanosheets. Based on the calculated exfoliation energies and the elastic constants, we propose that Mo(2)InC with the lowest exfoliation energy and the highest elastic constant anisotropy between C(11) and C(33) might be a suitable compound for exfoliation into 2D Mo(2)C nanosheets.