Synthesis of Hierarchical Porous Ni1.5Co1.5S4/g-C3N4 Composite for Supercapacitor with Excellent Cycle Stability

Abstract

In this work, the hierarchical porous Ni1.5Co1.5S4/g-C3N4 composite was prepared by growing Ni1.5Co1.5S4 nanoparticles on graphitic carbon nitride (g-C3N4) nanosheets via a hydrothermal route. Due to the self-assembly of larger size g-C3N4 nanosheets as a skeleton, the prepared nanocomposite possesses a unique hierarchical porous structure that can provide short ions diffusion and fast electron transport. As a result, the Ni1.5Co1.5S4/g-C3N4 composite exhibits a high specific capacitance of 1827 F g−1 at a current density of 1 A g−1, which is 1.53 times that of pure Ni1.5Co1.5S4 (1191 F g−1). In particular, the Ni1.5Co1.5S4/g-C3N4//activated carbon (AC) asymmetric supercapacitor delivers a high energy density of 49.0 Wh kg−1 at a power density of 799.0 W kg−1. Moreover, the assembled device shows outstanding cycle stability with 95.5% capacitance retention after 8000 cycles at a high current density of 10 A g−1. The attractive performance indicates that the easily synthesized and low-cost Ni1.5Co1.5S4/g-C3N4 composite would be a promising electrode material for supercapacitor application.

Self-Assembled Hierarchical Silkworm-Type Bimetallic Sulfide (NiMo3S4) Nanostructures Developed on S-g-C3N4 Sheets: Promising Electrode Material for Supercapacitors

“…Here, our NMS@S-gC//AC device in a two-series connection efficiently powers all LEDs ranging from red to blue. The overall outcome of this investigation discloses an enhanced performance of asymmetric g-C 3 N 4 composite-based supercapacitors using a new approach of self-assembled hierarchical silkworm-like electrode materials. − In previous investigations, various approaches had been reported for Co embodied with g-C 3 N 4 nanostructures because of superior theoretical values of Co and g-C 3 N 4 for storage applications, but here, we reported a new strategy with Mo rather than Co and the basic matrix also changed from g-C 3 N 4 to S-g-C 3 N 4 . Basically, g-C 3 N 4 is a 2D structure with a high nitrogen content, which enhances the electron-donor properties of the matrix and further leads to improved electron transportation of active material.…”

3D Assembly of CoAl2O4 Spinel Nanosheets for Energy Storage

“…The p-XRD pattern, SEM, high- and low-resolution TEM of this product are provided in Figure S4. The p-XRD peaks corresponding to planes (003), (006), (012), (015), (018), (110), (113), and (116) of CoAl-LDH/C (Figure S4a) suggest the formation of LDH phases due to the hydrothermal treatment in the first step of synthesis of CoAl 2 O 4 /C composite. ,, As presented in Figure S4b, the SEM image of the first step product shows 3D flowerlike morphology of CoAl-LDH/C composite. Figure S4c,d represents the high- and low-resolution TEM images of the CoAl-LDH/C composite.…”

Ni0.5Co0.5S nano-chains: a high-performing intercalating pseudocapacitive electrode in asymmetric supercapacitor (ASC) mode for the development of large-scale energy storage devices

“…Thus, the XPS study confirms the formation of Co 2+ , Ni 2+ , and S 2− oxidation states in the Ni 0.5 Co 0.5 S sample. 64,67…”

“…51,52 Bimetallic sulfides are regarded as a promising class of electrode materials for high-performance energy storage devices due to their exceptional electrochemical activity and capacity compared to most mono-metal sulfides. [53][54][55][56][57][58] Due to their distinctive physical, chemical, electrical, and optical properties, as well as their numerous potential applications in catalysis and electrochemical supercapacitors, Ni-Co-S compounds with different stoichiometric compositions, such as NiCo 2 S 4 , [59][60][61][62] CoNi 2 S 4 , [63][64][65] Ni 1.5 Co 1.5 S 4 , 66,67 Ni x Co 3−x S 4 , 68,69 (Ni 0.5 Co 0.5 ) 9 S 8 , 70 and Ni x Co 1−x S 2 , [71][72][73] have drawn significant attention. Electrochemical activities can be maximized by altering the active material compositions, fine-tuning the electronic struc-tures, and adjusting the active sites of materials.…”

“…Ni 1.5 Co 1.5 S 4 ,66,67 Ni x Co 3−x S 4 ,68,69 (Ni 0.5 Co 0.5 ) 9 S 8 ,70 and Ni x Co 1−x S 2 ,[71][72][73] have drawn significant attention.Electrochemical activities can be maximized by altering the active material compositions, fine-tuning the electronic struc-tures, and adjusting the active sites of materials. The ionic radius of Co 2+ is close to that of Ni 2+ as they are adjacent transition metal elements.…”