Facilitating the nucleophilic attack of metal centers by OH− for conducive adsorption of reaction intermediates and charge carriers along with easily accessible active sites is a determining factor for efficient Oxygen Evolution Reaction (OER) and pseudocapacitive charge storage. Herein, we report a bimetallic sulfide aerogel with hierarchical porosity prompting fast charge and mass transportation, while sulfurization and secondary metal incorporation instigate the increase of moderately binding active sites leading to favorable electrode-intermediate interaction. The electrode exhibits an overpotential of 335 mV at 500 mA cm−2 and a specific capacitance of 3983.2 Fg-1 at 1 Ag-1, with robust performance for 50 h and a 46% increase in capacity retention. From X-ray Photoelectron Spectroscopy (XPS) and Ammonia Temperature Programmed Desorption (NH3-TPD) analysis, lower Mδ+/M2/3+ results in higher OER performance, with Fe3+ in FeOOH providing moderately binding sites, while higher Mδ+/M2/3+ enhances cyclability for pseudocapacitive charge storage by inhibiting overoxidation and active site leaching. This work demonstrates the effect of simultaneous refinement of electronic structure and accessibility towards electrochemical performance by pairing the unique structural advantages of aerogels with the distinct chemical features of sulfides.
|Journal||Journal of Power Sources|
|Publication status||Published - 2023 Mar 15|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1A5A1019131 ).
© 2023 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering