Dual Functionality of Dichalcogenide-Supported Pentagon Core–Hexagon Ring-Structured NiCo₂O₄ Nanoplates: An Effective Hybridization for Tuning of a Diffused- to a Surface-Controlled Process and Boosting of CO₂ Electrocatalysis

Abstract

Rationally fabricating the hybrid nanostructures with a distinctive surface and internal properties is substantial due to their multifunctional features in energy storage and catalysis applications. Generally, the battery-like supercapacitor materials experience low energy density and inferior cyclic stability issues due to their intercalation/ deintercalation process. To address this problem, the dichalcogenides (WSe 2 and MoSe 2 ) were hybridized with a battery-like material (NiCo 2 O 4 ), which effectively changed the diffused-controlled to the surface-controlled process and enhanced the energy density and cyclic stability features. The pentagon core−hexagon ring-structured NiCo 2 O 4 nanoplate with MoSe 2 hybrid structures presents excellent electrochemical features with a specific capacity of 857 C g −1 at 1 A g −1 and retains 98% initial capacity after 5000 cycles at 30 A g −1 , which is higher than that of pure NiCo 2 O 4 and NiCo 2 O 4 /WSe 2 materials. The asymmetric supercapacitor device (NiCo 2 O 4 /MoSe 2 //activated carbon) provides an energy density of 69 W h kg −1 at a power density of 1280 W kg −1 and withstands an excellent cyclic stability of 95% after 10,000 cycles at 30 A g −1 . Moreover, a preliminary electrochemical analysis was performed to evaluate the CO 2 electro-reduction property of the hybrid structures using an H-type cell in a 0.5 M choline chloride electrolyte. The hybridization of MoSe 2 enhanced the CO 2 electro-reduction properties in the NiCo 2 O 4 material in terms of high current density, low overpotential, smaller equivalent series resistance, charge transfer resistance, and increased electrochemical surface area. These excellent supercapacitors and CO 2 electro-reduction performance provide valuable insights into the design and optimization of nonprecious hybrid materials for multifunctional applications and render a viable approach to enhance the internal properties of various materials in the future. KEYWORDS: supercapacitors, CO 2 electro-reduction, NiCo 2 O 4 /WSe 2 , NiCo 2 O 4 /MoSe 2 , diffusive-and surface-controlled processes, core−ring structure

Electrochemical Formation of Ionic Porous Organic Polymers Based on Viologen for Electrochromic Applications

“…The b ‐values of both iPOPs indicate that the electrochemical processes are a combination of diffused‐controlled and surface‐controlled processes. [ 28 ]…”

“…The b-values of both iPOPs indicate that the electrochemical processes are a combination of diffused-controlled and surface-controlled processes. [28] The obtained iPOP films were initially compared with their corresponding monomers using FT-IR spectroscopy to further confirm the successful preparation of the polymers (Figure S7, Supporting Information). The characteristic peak of pyridine can be observed at about 1634 cm −1 , which can be attributed to the stretching vibration of the C = N (𝜈 C = N ) in pyridinium salt groups.…”