Structural investigation of metallic Ni nanoparticles with N-doped carbon for efficient oxygen evolution reaction

In Situ Reconstructed Zn doped FexNi(1−x)OOH Catalyst for Efficient and Ultrastable Oxygen Evolution Reaction at High Current Densities

“…Considering that nickel-based materials can be easily oxidized in the OER process, the generated NiOOH should be due to the oxidation of NiO/NF support and NiZn alloy (Figure S16, Supporting Information), which is also consistent with previous operando X-ray absorption spectroscopy results. [44][45][46] Based on the above SEM, TEM-EDS, XRD, Raman results, it can be concluded that the as-prepared electrode underwent the merging of Zn doped FeOOH with in situ generated NiOOH during the high-rate OER process, [34] leading to the transform of Zn-(Ni/FeOOH)@NF to NF supported Zn doped solid solution of NiOOH-FeOOH (Zn-Fe x Ni (1−x) OOH@NF). The covalent interaction of FeOOH-NiOOH not only firmly anchors the catalyst to the NF support, but also helps to maintain excellent catalytic activity.…”

“…All Ni peaks (Ni 2+ /Ni 3+ 2p 3/2 and Ni δ+ , δ is likely close to 0) and Fe peaks (Fe 3+ 2p 1/2 and Fe 3+ 2p 3/2 ) in post-OER electrode have a positive shift compared to those of pristine electrode, which indicates that Fe and Ni were oxidized to a higher valence states during OER, favoring enhanced OER kinetics (Figure 4e,f). [46][47][48][49] Moreover, the Zn signal in the post-OER electrode was relatively weaker (Figure S17, Supporting Information), indicating that a small amount of Zn ions slowly dissolved in the electrolyte during the process, the dissolution of Zn might be the main reason for the slight degradation of catalytic performance.…”

Tuning d Orbital of Ni Single Atom by Encapsulating Ni Nanoparticle in Carbon Nanotube for Efficient Oxygen Evolution Reaction

“…Clearly, the adsorption energies of oxygenates on Ni111 are remarkably larger than those on NiN 4 and NiN 4 /Ni111 catalysts, indicating a stronger interaction between Ni111 and oxygenates. This strong adsorption on Ni111 leads to a low OER activity due to the prohibitive desorption process of O* and OOH* (Figure S14); thus, the large energy uphill from the OOH* to O 2 gives the calculated theoretical overpotential as high as 1.80 V. Previous investigations demonstrated that the slight surface oxidation can improve the catalytic activity of Ni nanoparticle . The adsorption strength of oxygenates on NiN 4 /Ni111 is enhanced in comparison with that on NiN 4 , while the adsorption energy difference of O* on NiN 4 and NiN 4 /Ni111 is larger than those of OH* and OOH*, indicating that the O* gets more electrons from NiN 4 /Ni111 than from NiN 4 (0.56 vs 0.49 e).…”

“…This strong adsorption on Ni111 leads to a low OER activity due to the prohibitive desorption process of O* and OOH* (Figure S14); thus, the large energy uphill from the OOH* to O 2 gives the calculated theoretical overpotential as high as 1.80 V. Previous investigations demonstrated that the slight surface oxidation can improve the catalytic activity of Ni nanoparticle. 54 The adsorption strength of oxygenates on NiN 4 /Ni111 is enhanced in comparison with that on NiN 4 , while the adsorption energy difference of O* on NiN 4 and…”

Designable synthesis of reactive deep eutectic solvents (RDESs) in regulating Ni-based materials for an efficient oxygen evolution reaction

“…35,36 For comparison, the presence of Ni( ii ) is related to the high oxidation valence (NiO), which is mainly attributed to the surface oxidation of Ni nanoparticles. 37 Both the increased amount of Ni( ii ) and the larger bonding energy indicate the interaction between Ni and Ni(OH) 2 , which can enhance the electrocatalytic performance of the catalyst. 38,39 In the O 1s spectra (Fig.…”