Facile fabrication of novel Ti3C2Tx-supported fallen leaf-like Bi2S3 nanopieces by a combined local-repulsion and macroscopic attraction strategy with enhanced symmetrical supercapacitor performance.

Hybrid electrode materials with superior electrochemical performance are highly desired to fulfil the ever-increasing energy-density demands of supercapacitors. Herein, a facile and efficient ion-attraction strategy is demonstrated for the construction of a uniform heterostructure of Bi 2 S 3 /Ti 3 C 2 T x (BSTC) nanocomposites, in which fallen leaf-like Bi 2 S 3 nanopieces are firstly planted on the surface of Ti 3 C 2 T x due to the local-repulsion of Ti atoms and the macroscopic attraction of functional groups (OH/O/F) to Bi3+. The DFT calculation was conducted to explain the morphology transformation mechanism from nanoparticles to nanopieces and the enhancement of the electrical conductivity of Bi 2 S 3 is due to the incorporation of Ti 3 C 2 T x. When used as a supercapacitor electrode, the BSTC-29 (Ti 3 C 2 T x content: 29 wt.%) nanocomposite exhibits a superior electrochemical performance with an enhanced capacity of 615 C g-1 at a high discharge current density of 3 A g-1, and a high capacitance retention up to 91% is also obtained due to the enhanced structural stability. Furthermore, the assembled symmetrical supercapacitor exhibits both a high energy density of 27.6 Wh kg-1 and a power density of 24.3 kW kg-1, respectively, surpassing those of Bi 2 S 3 and Ti 3 C 2 T x in this study and many other related composites in literature. This study presents a new promising strategy for the synthesis of high-performance supercapacitor electrode materials. [ABSTRACT FROM AUTHOR]