Designing of Kirkendall effect assisted CoFe : WS ₂ nanoboxes for dye‐sensitized solar cell and supercapacitor applications

Abstract

In this study, CoFe: tungsten disulfide (WS 2 ) hollow nanoboxes were synthesized for dye-sensitized solar cell (DSSC) and supercapacitor (SC) applications.Hollow nanoboxes structured as CoFe: WS 2 were synthesized using the facile hydrothermal and co-precipitation methods, combined with the ultrasonication technique as a pioneer. The morphological transformation from nanocubes to hollow nanoboxes (Kirkendall effect) was observed upon the incorporation of WS 2 quantum dots in an optimal ratio. The CoFe: WS 2 -2 hollow nanoboxes were employed as the counter electrode (CE) in DSSCs, which exhibit phenomenal catalytic activity in I 3 À electrolyte reduction and achieved a maximum power conversion efficiency (PCE) of 5.7%. Increased active sites for red-ox reaction and enhanced surface area due to the Kirkendall effect made the power conversion of the CoFe: WS 2 -2 DSSC device superior to that of platinum devices (4.0%). Supercapacitor performance of the CoFe: WS 2 -2 hollow nanoboxes shows a maximum specific capacitance of 551 F/g at a Current density of 1 A/g and the capacitance retention was noticed to be 88.96% in the three-electrode system using 2 M KOH as electrolyte. The asymmetric supercapacitor device exhibits an energy density of 37.18 Wh/kg and a power density of 875 W/kg at a current density of 1 A/g. The constructed CoFe: WS 2 -2//AC device reveals capacitance retention and coulombic efficiency of 71.99% and 98.18% after 6000 cycles, in the SC, respectively. The result emphasizes that hollow nanoboxes structured CoFe: WS 2 -2 can be an outstanding electrode in both DSSCs and SCs devices.

Cyanido-Bridged Bimetallic/rGO Electrodes for Dye-Sensitized Solar Cells and Battery-Type Supercapacitors

“…When two materials of various diffusivity concentrations were combined in the presence of external kinetic energy, the ion diffusion occurs from the higher to lower concentration region owing to the nonequality in their solubility and diffusion rate. 27 Here, when WS 2 / NiFe and rGO are brought into contact under probe sonication, the heterogeneity in the diffusion causes the movement of ions from the high concentration to lower concentration area. Initially, the nickel, iron, and tungsten ions move outward with simultaneous internal diffusion of sulfur ions.…”

“…The evolution of nanocage morphology can be described using the Kirkendall mechanism, Graham’s law of diffusion, and kinetic theory of solids. When two materials of various diffusivity concentrations were combined in the presence of external kinetic energy, the ion diffusion occurs from the higher to lower concentration region owing to the nonequality in their solubility and diffusion rate . Here, when WS 2 /NiFe and rGO are brought into contact under probe sonication, the heterogeneity in the diffusion causes the movement of ions from the high concentration to lower concentration area.…”

Designed fabrication of MoS2 hollow structures with different geometries and the comparative investigation toward capacitive properties

“…However, the structure of molybdenum disulfide is difficult to control during the simple hydrothermal process. 18 The combination of the hydrothermal method and template method may be a suitable method for preparing MoS 2 electrode materials with a hollow structure. 19 Zhang et al 20 reported a two-step template-assisted method to synthesize MoS 2 /PANI hollow microspheres as electrode materials for supercapacitors.…”

Nickel Telluride Quantum Dots as a Counter Electrode for an Efficient Dye-Sensitized Solar Cell

“…Their findings demonstrate that, by reducing the size of the material to that of QDs, the transportation and diffusion of ions within the material are significantly decreased. 23 Mohammadnezhad et al reported that incorporating lowdimensional nanocarbon, such as graphene, into a CuS composite improves its electrocatalytic properties and subsequently enhances the performance of DSSCs. 24 Akshaya et al 3 investigated WS 2 QDs coated over NiFe nanocube electrode materials.…”

“…Low-dimensional WS 2 electrode materials have been used for supercapacitors with an impressive performance. Their findings demonstrate that, by reducing the size of the material to that of QDs, the transportation and diffusion of ions within the material are significantly decreased . Mohammadnezhad et al reported that incorporating low-dimensional nanocarbon, such as graphene, into a CuS composite improves its electrocatalytic properties and subsequently enhances the performance of DSSCs .…”