FeSe/FeSe₂ Heterostructure as a Low‐Cost and High‐Performance Electrocatalyst for Oxygen Evolution Reaction

Abstract

A key consensus of implementing large-scale water splitting is developing highly efficient, durable, and earth-abundant electrocatalysts for oxygen evolution reaction (OER). In recent years, the Fe-based materials used in OER have attracted researchers' great attention around the globe, and Fe has been identified as the OER active sites. In this study, we firstly synthesized the coral-like FeSe/FeSe 2 heterostructure catalyst via a one-pot solvothermal method. We demonstrated that different components of FeSe/FeSe 2 heterostructure can facilitate the electron transfer process of the system, where a high Fe charge state promotes OER performance, rendering the coral-like FeSe/FeSe 2 heterostructure to be more promising Fe-based electrocatalyst for oxygen evolution reaction in alkaline. As expected, the asprepared FeSe/FeSe 2 heterostructure with highly charged iron and negatively charged selenium species exhibited better OER performance and needed only an overpotential of 309 mV to achieve an anodic current density of 10 mA cm À 2 . In addition, the catalyst had quick kinetics and good durability in alkaline medium. The present study would open up a potential avenue for the development of highly active non-noble-metal electrocatalysts.

UCoO4/Co3O4 Heterojunction as a Low-Cost and Efficient Electrocatalyst for Oxygen Evolution

“…The impedance data were fitted into an equivalent circuit using Zview software. All potential versus RHE was in accordance with the equation E (RHE) = E (Hg/HgO) + 0.059 × pH + 0.098 V …”

Expanding the Composition Range of Transition Metal Dichalcogenide Alloys, Fex(FeyV1–ySe2)

“…There is also a large overlap of the Fe 3p and Se 3d core levels, particularly complicating the analysis of the chemical states in the iron selenide compounds. As a consequence, XPS analysis of such compounds presented in the literature is oftentimes insufficient, incomplete, or conflicting. − …”

In situ construction of heterostructured CuxO@NiCoS nanoarrays for alkaline overall water splitting

“…In recent years, multiple types of transition metal-based electrocatalysts such as Mo,Co-NiS/NF, FeOOH/Ni 3 (NO 3 ) 2 (OH) 4 , Ni 5 P 4 -Co 2 P/NCF, Co 2 -P@NPPC, WC-W 2 C/HCDs, MoC/Mo 2 C, MoSe 2 /NiSe and FeSe/ FeSe 2 have been explored for water electrolysis. [16][17][18][19][20][21][22][23] Copper-based catalysts have been extensively employed in the energy eld owing to their high electrical conductivity, excellent catalytic activity, low price, high abundance and nontoxicity. [24][25][26] Among them, copper oxide with various morphologies can be used as an electrocatalyst or catalyst carrier for the OER.…”

“…In recent years, multiple types of transition metal-based electrocatalysts such as Mo,Co–NiS/NF, FeOOH/Ni 3 (NO 3 ) 2 (OH) 4 , Ni 5 P 4 –Co 2 P/NCF, Co 2 P@NPPC, WC–W 2 C/HCDs, MoC/Mo 2 C, MoSe 2 /NiSe and FeSe/FeSe 2 have been explored for water electrolysis. 16–23…”