Uncovering the Promotion of CeO₂/CoS_1.97 Heterostructure with Specific Spatial Architectures on Oxygen Evolution Reaction

Abstract

Structural engineering and compositional controlling are extensively applied in rationally designing and fabricating advanced freestanding electrocatalysts. The key relationship between the spatial distribution of components and enhanced electrocatalysis performance still needs further elaborate elucidation. Here, CeO2 substrate supported CoS1.97 (CeO2‐CoS1.97) and CoS1.97 with CeO2 surface decorated (CoS1.97‐CeO2) materials are constructed to comprehensively investigate the origin of spatial architectures for the oxygen evolution reaction (OER). CeO2‐CoS1.97 exhibits a low overpotential of 264 mV at 10 mA cm−2 due to the stable heterostructure and faster mass transfer. Meanwhile, CoS1.97‐CeO2 has a smaller Tafel slope of 49 mV dec−1 through enhanced adsorption of OH−, fast electron transfer, and in situ formation of Co(IV)O2 species under the OER condition. Furthermore, operando spectroscopic characterizations combined with theoretical calculations demonstrate that spatial architectures play a distinguished role in modulating the electronic structure and promoting the reconstruction from sulfide to oxyhydroxide toward higher chemical valence. The findings highlight spatial architectures and surface reconstruction in designing advanced electrocatalytic materials.

Two-dimensional heterostructures built from ultrathin CeO2 nanosheet surface-coordinated and confined metal–organic frameworks with enhanced stability and catalytic performance

“…Simultaneously, the oxygen storage capacity generated from the fast reversible variation between Ce 3+ and Ce 4+ and the surface defect-rich structure of ultrathin CeO 2 serves as an oxygen buffer to enhance wettability and release stress from a drastic reaction. 55 Though CeO 2 is not a good OER catalyst, these results clearly demonstrate that CeO 2 could essentially improve activity and stability of electrocatalysis by coordination with particular 2D MOF materials. 56 In comparison with other uniformly structured counterparts, 2D heterostructures exhibit greater stability and provide more efficient charge transfer.…”

Engineering NiMoO4/NiFe LDH/rGO multicomponent nanosheets toward enhanced electrocatalytic oxygen evolution reaction

“…In order to overcome these challenges, many effective strategies have been proposed, including modifying the surface and interface, 14,15 architecture engineering, 16,17 improving electronic conductivity, 18,19 etc. Among them, surface and interface engineering has been widely accepted as a promising route to modulate the surface and interface properties of catalysts, which not only boosts the exposure of surface active sites, but also facilitates the charge transfer via heterointerfaces during electrochemical reactions.…”

Iron-Facilitated Transformation of Mesoporous Spinel Nanosheets into Oxyhydroxide Active Species in the Oxygen Evolution Reaction

“…The XPS spectra of Fe 0.2 Ni 0.8 Co 2 O 4 nanosheets after the OER (Figure S9) were also observed to analyze the active species. The increased fitting peak area ratios of Ni 3+ /Ni 2+ , Co 3+ /Co 2+ , and M–OH/M–O indicate the formation of nickel/cobalt oxyhydroxide. , …”

“…The increased fitting peak area ratios of Ni 3+ /Ni 2+ , Co 3+ /Co 2+ , and M−OH/ M−O indicate the formation of nickel/cobalt oxyhydroxide. 38,39 4. CONCLUSIONS In this study, we synthesized pure NiCo 2 O 4 and a series of Fesubstituted NiCo 2 O 4 -based spinel oxide.…”