| Title |
Hierarchical NiFe-LDH on Conductive Ni3Se2 Scaffolds for Efficient Oxygen Evolution Reaction |
| Authors |
안태광(Tae Kwang An) ; 장윤석(Yun Seok Jang) ; 유동현(Dong Hyun You) ; 권순용(Soon-Yong Kweon) ; 류정호(Jeong Ho Ryu) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.12.976 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Alkaline water electrolysis; Interfacial charge transfer; NiFe-LDH/Ni3Se2@NF; Nickel selenide (Ni3Se2); Oxygen evolution reaction (OER) |
| Abstract |
Developing earth-abundant oxygen-evolution reaction (OER) electrodes that operate
efficiently at practical current densities remains a challenge because NiFe layered double hydroxides (LDHs),
which are among the most active non-noble catalysts in alkaline media, are limited by poor electronic
conductivity, nanosheet restacking, and weak contact with current collectors. Herein, we develop a binderfree,
integrated NiFe-LDH/Ni3Se2@nickel foam (NF) electrode fabricated using a sequential hydrothermal
route: Ni3Se2 is first grown on NF using Se powder and hydrazine, followed by the in-situ deposition of NiFe-
LDH nanosheets. X-ray diffraction verifies the crystalline Ni3Se2 backbone and, after LDH growth, a
diagnostic low-angle peak near 2θ ? 11o is observed, assigned to the (003) basal reflection of hydrotalcite-like
LDH. Field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy reveal conformal
LDH coverage on the selenide scaffold with uniform Ni, Fe, and O signals, whereas X-ray photoelectron
spectroscopy shows mixed-valent Ni2+/Ni3+ and Fe3+ in the shell, preserved Se2- from the core, and hydroxyl/
water species in O 1s, consistent with a hydrotalcite-like surface that readily evolves to Ni(Fe)OOH under
an anodic bias. Electrochemically, the heterostructure exhibits lower overpotentials at 50?100 mA·cm-2, a
smaller Tafel slope, and reduced charge-transfer resistance relative to NiFe-LDH@NF and Ni3Se2@NF. The
gains correlate with the largest double-layer capacitance and electrochemically active surface area, and the
electrode exhibits stable chronopotentiometric operation. We attribute this performance to synergistic
interfacial coupling and rapid electron-transport through Ni3Se2, together with abundant, well-wired LDH
active sites and improved mass transport in the open 3D foam. This study provides a general strategy for
fabricating high-rate alkaline OER electrodes based on LDH/metal selenide heterostructure. |