Ultrathin Bi2Se3/graphene derived from Bi-based metal-organic-framework as superior electrode material for sodium-ion storage

• Morphology control of Bi 2 Se 3 /NG-7 is realized via using N-dope graphene template. • Multi-heteroatom doping is realized for Bi 2 Se 3 /NG-7 via using the HCTP-COOH ligand. • Bi 2 Se 3 /NG-7 shows advanced electrochemical performance for sodium-ion storage. Herein, we synthesized a multi-heteroatom doped ultrathin nanosheet Bi 2 Se 3 /N-doped graphene (NG) composite by using hexa(4-carboxyl-phenoxy)-cyclotriphosphazene (HCTP-COOH) containing Bi-MOF/NG as the precursor through a simple selenization step. Compared with pure Bi 2 Se 3 , Bi 2 Se 3 /NG with an ultrathin nanosheet structure displays significantly improved rate capacity and cycling performance while used as an anode for sodium-ion batteries. The enhanced electrochemical performance of the Bi 2 Se 3 /NG composite can be ascribed to the special nanosheet structures and multi-heteroatom doping in the carbon matrix.