Operando Unraveling of the Structural and Chemical
Stability of P‑Substituted CoSe<sub>2</sub> Electrocatalysts
toward Hydrogen and Oxygen Evolution Reactions in Alkaline Electrolyte
Yanping Zhu
Hsiao-Chien Chen
Chia-Shuo Hsu
Ting-Sheng Lin
Chia-Jui Chang
Sung-Chun Chang
Li-Duan Tsai
Hao Ming Chen
10.1021/acsenergylett.9b00382.s002
https://acs.figshare.com/articles/media/Operando_Unraveling_of_the_Structural_and_Chemical_Stability_of_P_Substituted_CoSe_sub_2_sub_Electrocatalysts_toward_Hydrogen_and_Oxygen_Evolution_Reactions_in_Alkaline_Electrolyte/7952873
The question of whether
the metal chalcogenides (phosphides) that
have been acknowledged to be efficient materials for bifunctional
electrocatalysts really perform as the active species or just “pre-catalysts”
has been debated. Herein, a series of operando measurements, including
in situ X-ray absorption spectroscopy, liquid-phase transmission electron
microscopy, and in situ Raman spectroscopy, were conducted to unravel
in real time the structural and chemical stability of P-substituted
CoSe<sub>2</sub> electrocatalysts under both hydrogen and oxygen evolution
reactions (HER and OER, respectively) in an alkaline electrolyte.
It can be conclusively revealed that, in an alkaline electrolyte,
the P-substituted CoSe<sub>2</sub> electrocatalyst was acting as the
“pre-catalyst” rather than the real reactive species.
The introduction of phosphorus is speculated to generate more vacancies
or defects around Co cations in the initial CoSe<sub>2</sub> and considerably
facilitates the structural transformation into the “real reactive
species”, such as metallic cobalt (for HER) and cobalt oxyhydroxide
(for OER).
2019-03-27 00:00:00
bifunctional electrocatalysts
P-substituted CoSe 2 electrocatalysts
X-ray absorption spectroscopy
Raman spectroscopy
chemical stability
electrolyte
liquid-phase transmission electron microscopy
CoSe 2
HER
operando measurements
oxygen evolution reactions
Chemical Stability
Co cations
Operando Unraveling
Oxygen Evolution Reactions
reactive species
P-substituted CoSe 2 electrocatalyst
pre-catalyst
OER
metal chalcogenides
cobalt oxyhydroxide
Alkaline Electrolyte