Corrosion engineering approach to rapidly prepare Ni(Fe)OOH/Ni(Fe)S_x nanosheet arrays for efficient water oxidation

Abstract

The Ni-Fe composites catalyst is in-depth research due to high intrinsic activity in electrochemical water splitting applications. Corrosion engineering is considered as an effective strategy to prepare large-scale Ni-Fe composites...

In Situ Raman Study of Surface Reconstruction of FeOOH/Ni3S2 Oxygen Evolution Reaction Electrocatalysts

“…[ 38,40–42 ] Overall, the enhanced OER performance of the FeOOH/Ni 3 S 2 /NF composite structure is driven by the phase transition of FeOOH and the increased disorder of NiOOH. [ 28,29 ]…”

“…The crystal structure of as-prepared Ni [24,25] In addition to the Ni─S bonds at 304 and 351 cm −1 in FeOOH/Ni 3 S 2 /NF, emerged peaks located at 242 and 386 cm −1 can be ascribed to the Fe─O bond of 𝛼-FeOOH, and those located at 452 and 531 cm −1 belong to the Ni-O stretching vibration. [17,[26][27][28] Moreover, The XRD pattern of FeOOH/NF only exhibits the peaks corresponding to nickel foam (PDF#87-0712), demonstrating that the FeOOH is poorly crystalline. We further confirmed the bonding and composition of the samples by Raman spectroscopy.…”

“…[38,[40][41][42] Overall, the enhanced OER performance of the FeOOH/Ni 3 S 2 /NF composite structure is driven by the phase transition of FeOOH and the increased disorder of NiOOH. [28,29] Based on the above phenomena, theoretical calculations are adopted to reveal the phase transformation of FeOOH in OER process. As shown in Figure 4e, the crystal orbital Hamilton population (COHP) analysis was performed for Fe─O bond in 𝛼-FeOOH and 𝛽-FeOOH to compare the composition of bonding orbitals and anti-bonding orbitals.…”

“…It is demonstrated that the anti-bonding orbital of the Fe─O bond of 𝛼-FeOOH is partially filled and the 𝛼-FeOOH is less stable than the 𝛽-FeOOH, indicating that 𝛼-FeOOH is more easily transformed into 𝛽-FeOOH with higher stability. [28,43] S24a, Supporting Information), and a pair of new fitting peaks appeared at 875.36 and 856.55 eV, corresponding to the 2p 3/2 and 2p 5/2 of Ni 3+ , demonstrating partial Ni 2+ is oxidized during the OER process. [15] A relatively higher before OER/after OER ratio of Ni 2+ is obtained for FeOOH/Ni 3 S 2 (3.871) compared to the Ni 3 S 2 (1.635) (Figure S24e, Supporting Information).…”

Atomically precise copper nanoclusters as a potential catalyst for the electrochemical oxygen evolution reaction

“…Noble metal oxides (e.g., RuO 2 and IrO 2 ), mixed metal clusters and transition metal layered double hydroxides exhibit excellent electrocatalytic activity for OER. 49,50 However, the high cost of the metal precursors, poor catalytic activity, high overpotential, and poor stability of the catalyst highlight the need to develop better catalysts. In this regard, earth-abundant non-noble metals (Ni, Co, Fe and Cu) and their related single atom catalysts (SACs), 51,52 hydroxides, 53 phosphides/phosphates, 54,55 MOFs, 56 nano-clusters 57 and inorganic hybrids 58,59 are being investigated as an electrocatalyst for OER.…”