Template-Assisted Fabrication of ZnO/Co₃O₄ One-Dimensional Metal–Organic Framework Array Decorated with Amorphous Iron Oxide/Hydroxide Nanoparticles as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

Abstract

The construction of new electrocatalysts for effective and low-cost water electrolysis continues to be an important conceptual barrier for clean renewable energy technologies. Herein, we fabricate a unique approach to a stable metal−organic framework (MOF) based on zinc oxide/cobalt oxide (MOF ZnO/Co 3 O 4 ) array synthesis aided by a sacrificial template technique and followed by the decoration of three-dimensional MOF arrays using amorphous iron oxide/hydroxide (FeOOH) nanoparticles. The highly active FeOOH nanoparticles are tightly bound to the surface of the MOF ZnO/Co 3 O 4 array. These integrated heterostructures provide copious active sites, a large electrochemical surface area, an effective charge-mass transfer, and a strong integration between MOF ZnO/Co 3 O 4 and FeOOH nanoparticles. Ascribed to all such aspects, FeOOH @ MOF ZnO/Co 3 O 4 nanorods supported on nickel foam show an oxygen evolution reaction activity order of magnitude higher than that of individual entities in an alkaline solution with an overpotential of 260 mV achieved at a current density of 50 mA•cm −2 and a Tafel slope of 48 mV dec −1 . This behavior can be ascribed to the effect of amorphous FeOOH nanoparticles being tightly anchored on the MOF ZnO/Co 3 O 4 surface, which not only synergistically enriches the electrochemical surface area but also enhances the active sites. This work offers to open a new strategy to design and fabricate advanced electrode materials for the water electrolysis process.

Integration of Cobalt Metal–Organic Frameworks into an Interpenetrated Prussian Blue Analogue to Derive Dual Metal–Organic Framework-Assisted Cobalt Iron Derivatives for Enhancing Electrochemical Total Water Splitting

“…46 Reduced phosphorus binding energies indicate a slightly negative shift relative to elemental P (130.0 eV), denoting a definite transfer of electron density from MOF CoFeP to P. In addition to one broad peak at 133.9 eV, which is attributed to oxidized phosphorus (PO 4 3− ), the surface oxidation of MOF CoFeP is caused by exposure to air. 45 In the C 1s spectrum (Figure 3D), the peaks at 284.5 and 285.8 eV are attributed to typical CC and CO bonds, respectively. Additionally, O 1s spectra reveal the peak observed at 530 eV, due to surface oxidation with atmospheric oxygen (Figure S5B).…”

A Review of Electrospun Carbon Nanofiber-Based Negative Electrode Materials for Supercapacitors

“…The BET surface area was observed to be almost 50 times that of pure ECNFs. Therefore, compared to conventional materials, MOF-based nanomaterials usually exhibit a controllable porous architecture and pore volume along with an extraordinarily large surface area [108,[110][111][112][113][114]. Furthermore, no additional template is required for promoting porosity.…”

Synthesis Methods and Applications of Semiconductor Material ZnWO4 with Multifunctions and Multiconstructions

“…Based on these advantages, the template method is widely used to prepare nanomaterials and nanoarrays. Kim and co‐workers [ 152 ] synthesized FeOOH‐modified MOF ZnO/Co 3 O 4 nanoarrays by the template method. Due to its synergistic effect, the heterostructure has a large specific surface area, abundant active sites, and fast charge transfer, which can be used to design advanced electrode materials.…”