Ultrathin Co–Fe hydroxide nanosheet arrays for improved oxygen evolution during water splitting

Abstract

The Fe-doping of hierarchical Co hydroxide nanosheet arrays (CoyFe1−y(OH)x NSAs) integrated on a three-dimensional electrode is shown to contribute to both increasing the available surface area and number of active sites.

Host-Guest Engineering of Layered Double Hydroxides towards Efficient Oxygen Evolution Reaction: Recent Advances and Perspectives

“…As a result, a high OER rate of 80 mA cm −2 for the H-LDHs could be readily achieved by applying a small overpotential (257 mV for H-LDH-1), much better than that of the Co 2 (OH) 2 CO 3 nanowire arrays (420 mV) and LDH NPs (492 mV). Zhao et al fabricated CoFe-LDH NSAs by a solution phase cation exchange method at room temperature by dipping the Cu foam loaded with Cu 2 O nanoarrays into an aqueous solution of CoCl 2 and FeCl 2 (Figure 6d) [74]. In this process, OH − was generated in situ along with the etching of electrocatalysts for OER and HER were further used for the overall water splitting in a two-electrode electrolysis cell (Figure 5h), which just needs a cell voltage of 1.59 V to give a water splitting current density of 10 mA cm −2 in 1.0 M KOH solution with a scan rate of 2 mV s −1 (Figure 5i).…”

Novel synthetic strategy for a nanostructured metal hydroxysulfide‐C and its initial electrochemical investigation as a new anode material for potassium‐ion batteries

“…Several peaks attributed to Co-OH and Co-S bonds appeared in the vicinity of 780.5/796.0 and 778.0/793.5 eV in the Co 2p spectrum, respectively (Figure S3a). 30 Furthermore, the O 1 s and S 2p spectra in Figures S3b and S3c, respectively, revealed peaks at 531.5 and 161.0/162.5 eV, which corresponded to the Co-OH and Co-S bonds, respectively. 30,31 The additional peaks centered around 530.5 eV in the O 1 s spectrum and 168.0 eV in the S 2p spectrum were attributed to the oxidation of the Co(OH)S surface.…”

“…30 Furthermore, the O 1 s and S 2p spectra in Figures S3b and S3c, respectively, revealed peaks at 531.5 and 161.0/162.5 eV, which corresponded to the Co-OH and Co-S bonds, respectively. 30,31 The additional peaks centered around 530.5 eV in the O 1 s spectrum and 168.0 eV in the S 2p spectrum were attributed to the oxidation of the Co(OH)S surface. 31 The unusual bands at 1399 and 572/1091 cm À1 in the FTIR spectrum (Figure S3d) were ascribed to the metalÀOH stretching vibration mode and the metaÀS bending vibration mode, respectively, further demonstrating the formation of the Co(OH)S phase.…”

Ultrathin Nanosheet-Assembled Co–Fe Hydroxide Nanotubes: Sacrificial Template Synthesis, Topotactic Transformation, and Their Application as Electrocatalysts for Efficient Oxygen Evolution Reaction

“…The high-resolution XPS Co 2p spectra of Co 0.8 Fe 0.2 hydroxide nanotubes and Co 0.8 Fe 0.2 P nanotubes are displayed in Figure b. Both spectra show two characteristic peaks of Co 2p 1/2 and Co 2p 3/2 at the positions of 797.8 and 782.2 eV, respectively, which are identified as Co 2+ . Another two peaks of Co 2p 1/2 and Co 2p 3/2 centered at 796.1 and 780.5 eV, respectively, of Co 0.8 Fe 0.2 hydroxide nanotubes are assigned to Co 3+ . , Whereas the Co 2p 1/2 and Co 2p 3/2 peaks of Co 0.8 Fe 0.2 P nanotubes are observed at 778.8 and 793.6 eV, respectively, which should correspond to Co + .…”