As one of the classic transition metal carbides, two-dimensional (2D) Mo2C possesses a wealth of controllable electronic properties and exhibits great application potential in the field of photocatalysis, energy storage, and superconductivity due to its variety of charge, orbital and spin degree of freedom. According to the first principles calculations, the superconducting transition temperature value of 2D Mo2C, strongly related to its electronic structure, varies in the range of 2 - 13 K. Therefore, tuning the electronic structure will be the key issue to obtaining the Mo2C with high-quality and superior performance. In this study, we adopted a topochemical method to synthesize 2D Mo2C powders with high quality. Based on that, the F-Mo2C and N, P-Mo2C samples are prepared by fluorine modification and N, P co-doping, respectively. Moreover, the surface morphology, electronic structure, and superconductivity of all samples are systematically studied as well as the superconductivity.
The superconducting transition temperature (Tc) of the Mo2C sample was measured by using the zero-field cooling (ZFC) and field cooling (FC) modes; the value of H was 10 Oe. The values of Tc were determined from the M/H – T plot in ZFC mode. In comparison with 3.2 K of the pure Mo2C sample, the highest Tc value of 5.7 K and 6.1 K can be obtained in F-Mo2C sample and N, P-co-doped Mo2C sample, respectively.
[1] Liu H-D, Lu H-Y, Jiao N, et al. Physic. Chem. Chem. Physic., 2023, 25(1): 580-589.
[2] Guo Y, Xu K, Wu C, et al. Chem. Soc. Rev., 2015, 44(3): 637-646.
This work was supported by Northwest Institute for Non-ferrous Metal Research (No. YK2110), National Key Research and Development Program of China (No. 2021YFB3800200).
Keywords: molybdenum carbide, topochemical transformation, surface functionalization, superconductivity