Ultra‐thin Co−Fe Layered Double Hydroxide Hollow Nanocubes for Efficient Electrocatalytic Water Oxidation

Abstract

Hierarchical hollow nanocubes based on ultra‐thin CoFe‐layered double hydroxide (CoFe−LDH) nanosheets have been prepared. The obtained CoFe−LDH hollow nanocubes could effectively catalyze water oxidation at a low overpotential of 270 mV @ 10 mA cm−2, low Tafel slope of 58.3 mV dec−1 and show a long‐term stability in alkali.

Dynamic Morphological Evolution of Co-Based Layered Double Hydroxide Nanosheets Investigated by In Situ Electrochemical-Atomic Force Microscopy

“…The information about the precise binding energy is presented in Table S3. The peaks located at ∼781.5 and ∼797.5 eV in the Co 2p spectra of six Co-based LDH nanosheets correspond to Co 2p 3/2 and Co 2p 1/2 , while the other two peaks located at ∼786.0 and ∼802.5 eV are attributed to the corresponding shakeup satellites (Figure D). , These results indicate that the Co oxidation state of six Co-based LDH nanosheets is mainly +2. , The O 1s spectra of six Co-based LDH nanosheets can be classified as deconvoluted into three peaks located at 532.9, ∼530.0, and ∼531.5 eV, corresponding to the adsorbed H 2 O molecules, metal–oxygen bonds (M–O–M), and hydroxyl groups (−OH), respectively (Figure E) . The O 1s binding energy of the CoAl-LDH nanosheets is higher than that of CoFe-LDH nanosheets (Figure E and Table S3), which suggests that the binding strength of metal–oxygen bonds of the CoAl-LDH nanosheets is stronger .…”

“…28,29 These results indicate that the Co oxidation state of six Co-based LDH nanosheets is mainly +2. 28,29 The O 1s spectra of six Co-based LDH nanosheets can be classified as deconvoluted into three peaks located at 532.9, ∼530.0, and ∼531.5 eV, corresponding to the adsorbed H 2 O molecules, metal−oxygen bonds (M−O−M), and hydroxyl groups (−OH), respectively (Figure 2E). 30 The O 1s binding energy of the CoAl-LDH nanosheets is higher than that of CoFe-LDH nanosheets (Figure 2E and Table S3), which suggests that the binding strength of metal−oxygen bonds of the CoAl-LDH nanosheets is stronger.…”

“…The peaks located at ∼781.5 and ∼797.5 eV in the Co 2p spectra of six Co-based LDH nanosheets correspond to Co 2p 3/2 and Co 2p 1/2 , while the other two peaks located at ∼786.0 and ∼802.5 eV are attributed to the corresponding shakeup satellites (Figure 2D). 28,29 These results indicate that the Co oxidation state of six Co-based LDH nanosheets is mainly +2. 28,29 The O 1s spectra of six Co-based LDH nanosheets can be classified as deconvoluted into three peaks located at 532.9, ∼530.0, and ∼531.5 eV, corresponding to the adsorbed H 2 O molecules, metal−oxygen bonds (M−O−M), and hydroxyl groups (−OH), respectively (Figure 2E).…”

Mesostructuring layered materials: self-supported mesoporous layered double hydroxide nanotubes

“…LDHs consequently are materials easily customizable to fulfil multiple different functions. They have successfully been used as catalysts, solid electrolytes, drug delivery vectors and adsorbents 4,[6][7][8][9][10][11][12][13][14] .…”

Coordination of Eu3+ Activators in ZnAlEu Layered Double Hydroxides Intercalated by Isophthalate and Nitrilotriacetate

“…This results in a general formula [M 1– x II M III x (OH) 2 ]­[A n – ] x / n · m H 2 O, such as in the natural mineral hydrotalcite, where part of the Mg II is replaced by Al III . LDH minerals exhibit a wide flexibility in composition and a score of polyvalent ions can be introduced into the layers. , The versatile composition of the LDH unlocks large application possibilities in diverse research fields, such as catalysis, electrolysis, drug delivery, and environmental sciences. − …”