Flower-like Mo doped Ni(OH)2@Co3S4-Ni3S2 heterostructure for asymmetric supercapacitors

Abstract

The construction of heterostructures is a common means for obtaining new high-performance materials. On this basis, doping of metallic elements tends to achieve surprising expectations. Here, Ni(OH)(2)@Co3S4-Mo-Ni3S2 heterostructures were obtained by doping molybdenum into cobalt sulfide layers through a facile two-step hydrothermal synthesis method. Impressively, the doping of Mo also affected the Ni-O bond interaction, and this cross-component synergistic effect led to the generation of defects and triggered an overall improvement in the properties of the original Ni(OH)(2)@Co3S4-Ni(3)S(2 )material. The results showed that the specific surface area increased from 24.4 m(2)/g to 53.8 m(2)/g after Mo doping, and the Ni(OH)(2)@Co3S4-Mo-Ni3S2 electrode exhibited twice the specific capacitance (2869: 1360 F g(-1) = 2.1) at a current of 2 A g(-1). Likewise, after 5000 cycles, the capacitance retention of the Ni(OH)(2)@Co3S4-Mo-Ni3S2 electrode was 86.7%, better than the 82.5% before doping. To further explore its practicality, the Ni(OH)(2)@Co3S4-Mo-Ni3S2//AC ACS device was assembled, delivering a maximum energy density of 56.2 W h kg(-1) at a power density of 213.4 W kg(-1) and showing good cycling stability (91.2% capacitance retention after 5000 cycles). This work demonstrates that Mo doping for modification of heterostructures to further improve performance is a feasible and prospective approach.& nbsp;