Fluorine-doped nickel oxyhydroxide as a robust electrocatalyst for oxygen evolution reaction

(Fe, F) co-doped nickel oxyhydroxide for highly efficient oxygen evolution reaction

“…In our recent study of a F–NiOOH system, we obtained experimental and computational results supporting the F − substitution of OH − in the NiOOH surface layer. 35 Furthermore, our study and those by others demonstrated that substitutional F-doping resulted in significant improvement of OER activity. 35–37 This finding not only demonstrated the feasibility of improving OER activity from the anion side, but also provided an opportunity for anion–cation co-doping.…”

“…According to a previous study by Bell et al, 43 incorporation of Fe cations into γ-NiOOH could dramatically change the chemical bonding of Fe, Ni surface sites with the intermediates involved in the OER, resulting in variation of the relative stability of O* with respect to OH* and OOH*. In our preliminary study of a F–NiOOH system, 35 theoretical computation results indicated that F substitution of the surface OH group in NiOOH leads to increased electron donation of the adjacent Ni cations to F. As a consequence of the altered surface electronic properties, the adsorption of OH on the surface Ni site became stronger, making its deprotonation (*OH → *O) as the potential-limiting step. Whereas for pure NiOOH, the adsorption of OH on the Ni site (* → *OH) is the potential-limiting step with a higher free energy change.…”

“…35 Furthermore, our study and those by others demonstrated that substitutional F-doping resulted in signicant improvement of OER activity. [35][36][37] This nding not only demonstrated the feasibility of improving OER activity from the anion side, but also provided an opportunity for anion-cation co-doping. In comparison with cation-doping, anion-cation codoping may provide a greater degree of freedom to successfully engineer the surface properties of OER electrocatalysts.…”

Achieving High‐Performance Electrocatalytic Water Oxidation on Ni(OH)2 with Optimized Intermediate Binding Energy Enabled by S‐Doping and CeO2‐Interfacing

“…The location of the peaks for Ni 2+ and metallic Ni are the same as before OER stability measurement, and the emerged peaks for Ni-O and Ni 3+ may originate from the oxidation of uncovered Ni foam and Ni(OH) 2 during the OER condition, respectively, suggesting further some of Ni(OH) 2 is converted to NiOOH. [33,39] The intensity of the S 2p XPS spectrum of S-Ni(OH) 2 /CeO 2 /NF after the stability test is lower than that of before suggesting some of the S element leached after long-time OER measurement (Figure S10b, Supporting Information). The high-resolution Ce 3d XPS spectrum of S-Ni(OH) 2 /CeO 2 /NF after OER stability test (Figure S10c, Supporting Information) can also be deconvoluted into several peaks marked as u 0 , u, u′, u′′, and u′′′ assigning to Ce 3d 3/2 while the v′′′ belong to Ce 3d 5/2 .…”