Hierarchical architecture of Ti3C2@PDA/NiCo2S4 composite electrode as high-performance supercapacitors

A novel Ti 3 C 2 @PDA/NiCo 2 S 4 composites as high performance supercapacitor electrodes were synthesized by the hydrothermal treatment process. The chemical modification and uniformly coating of Ti 3 C 2 surface by polydopamine (PDA) can prevent the structural collapse and over-oxidation of Ti 3 C 2 during the hydrothermal synthesis of NiCo 2 S 4 . Furthermore, the confined-synthesis of smaller NiCo 2 S 4 particles between the Ti 3 C 2 layers, not only prevent the restacking of Ti 3 C 2 that between the adjacent monolayers during cycling, but also afford high surface areas accessible to charge transfer and ion diffusion. Thereby, enhance the electrochemical cycling stability of the Ti 3 C 2 @PDA/NiCo 2 S 4 composite. It is significant to explore how NiCo 2 S 4 alters the microstructure, morphology as well as supercapacitors performance of Ti 3 C 2 to tune the microstructure and performance of Ti 3 C 2 by appropriate hydrothermal synthesis strategy. The experimental results exhibit a prominent improvement in the supercapacitor performance, the gravimetric capacitance of Ti 3 C 2 @PDA/NiCo 2 S 4 composites achieve as high as 495 F g -1 at 2 mV s -1 , which increase the 10 times as compared to the pristine Ti 3 C 2 . Furthermore, the cycling stability of the Ti 3 C 2 @PDA/NiCo 2 S 4 composites electrode was enhanced significantly by the hierarchical architecture, and showed exceptional capacitance retention (81.16%) even after 3000 cycles. The dramatic improvement in the supercapacitors performance of Ti 3 C 2 @PDA/NiCo 2 S 4 electrodes is attributed to impressive conductive matrix Ti 3 C 2 , the effective modification of small size Ni 2 Co 2 S 4 , and the strong interfacial interaction between Ti 3 C 2 @PDA and NiCo 2 S 4 . This study demonstrating its attractive application prospect of Ti 3 C 2 Mxenes modified with bimetallic sulfide as electrode materials for high-performance supercapacitors.