This study first presents a subtle thermal-chlorination strategy for a universal transformation of abundant 2D metal carbides (M_xC_y, e.g., Cr₃C₂, Mo₂C, NbC, and VC) to 2D graphene and M-self-doped graphene (MG). The as-obtained MG endows a transparent sheet architecture of one to four atomic layers. Simultaneously, MG with different M amounts is synthesized by tuning the chlorination parameters. Among them, the novel and representative Cr-self-doped graphene with optimal Cr amount (4.81 at%) demonstrates the outstanding electrochemical performance. It presents an energy density of 686 W h per kg electrode and a power density of more than 391 W per kg electrode as anode material of Li ion batteries, and four-fold activity against the commercial iridium oxide electrode toward oxygen evolution reaction as well as a comparable oxygen reduction reaction performance to the commercial platinum catalyst. Moreover, this method is readily scalable to produce graphene and MG electrode materials on industrial levels.

Zongkui Kou, Tian Meng, Beibei Guo,Ibrahim Saana Amiinu, Wenqiang Li, Jie Zhang, Shichun Mu*. A generic conversion strategy: From 2D metal carbides (MxCy) to M-self-doped graphene towards high-efficiency energy applications. Advanced Functional Materials, 2017, 27(8), 1604904.

http://onlinelibrary.wiley.com/doi/10.1002/adfm.201604904/abstract