Transition Metal Carbo‐Chalcogenide “TMCC:” A New Family of 2D Materials

Here, a new family of 2D transition metal carbo‐chalcogenides (TMCCs) is reported, which can be considered a combination of two well‐known families, TM carbides (MXenes) and TM dichalcogenides (TMDCs), at the atomic level. Single sheets are successfully obtained from multilayered Nb2S2C and Ta2S2C using electrochemical lithiation followed by sonication in water. The parent multilayered TMCCs are synthesized using a simple, scalable solid‐state synthesis followed by a topochemical reaction. Superconductivity transition is observed at 7.55 K for Nb2S2C. The delaminated Nb2S2C outperforms both multilayered Nb2S2C and delaminated NbS2 as an electrode material for Li‐ion batteries. Ab initio calculations predict the elastic constant of TMCC to be over 50% higher than that of TMDC.