Hollow Iron–Vanadium Composite Spheres: A Highly Efficient Iron‐Based Water Oxidation Electrocatalyst without the Need for Nickel or Cobalt

Abstract

Noble-metal-free bimetal-based electrocatalysts have shown high efficiency for water oxidation. Ni and/or Co in these electrocatalysts are essential to provide a conductive, high-surface area and a chemically stable host. However, the necessity of Ni or Co limits the scope of low-cost electrocatalysts. Herein, we report a hierarchical hollow FeV composite, which is Ni- and Co-free and highly efficient for electrocatalytic water oxidation with low overpotential 390 mV (10 mA cm catalytic current density), low Tafel slope of 36.7 mV dec , and a considerable durability. This work provides a novel and efficient catalyst, and greatly expands the scope of low-cost Fe-based electrocatalysts for water splitting without need of Ni or Co.

Oxygen Vacancy Engineering of Co3O4 Nanocrystals through Coupling with Metal Support for Water Oxidation

“…It is interesting that the distribution and crystallinity of these Co 3 O 4 nanocrystals and their coupled interface with the Ti mesh were not disturbed obviously as indicated by the SEM, HRTEM, and XPS results ( Figure S12 and S15). [7,15,16] Besides capturing hydroxyl groups as already presented by the O1sX PS peak at 531.17 eV (Figure 3d), [17] the oxygen vacancies also act as active centers for further oxidation reactions. Thea tomic ratios of Co and Oo fn-Co 3 O 4 /Ti( n = 1, 2, 3, 4and represents different loading) electrodes correlated well with the current density at 1.8 Vv ersus RHE.…”

Iron–Salen Complex and Co2+ Ion‐Derived Cobalt–Iron Hydroxide/Carbon Nanohybrid as an Efficient Oxygen Evolution Electrocatalyst

“…XPS spectrum in Figure S6a (Supporting Information) shows same element compositions as determined from EDX measurements. [32,36,37] The Co 2p spectrum in Figure 2b can be deconvoluted into two spin-orbit peaks at the binding energies of 781.2 (Co 2p 3/2 ) and 796.8 eV (Co 2p 1/2 ), and the corresponding satellite peaks at 786.1 and 803.1 eV are consistent with the presence of Co 2+ . In Figure 2a, the XPS spectrum of Fe 2p is featured with two satellite peaks at 718.3 and 733.2 eV, respectively, providing solid evidence to the presence of Fe 3+ .…”

Facile Synthesis of Sulfur‐Containing Transition Metal (Mn, Fe, Co, and Ni) (Hydr)oxides for Efficient Oxygen Evolution Reaction

“…We developed a scalable one-step wet chemical method to prepare sulfur-containing transition metal (manganese, iron, cobalt, and nickel) (hydr)oxides coupled with carbon nanotubes as additives to tailor OER performance. [13,14] Such strategies include, 1) creating nanostructures and reducing the catalyst size to raise the exposure of active sites and the electrochemically active surface area; [15,16] 2) increasing the electric conductivity by coupling the catalyst with conductive compounds like nickel foam, [17] transition metal chalcogenides, [18] and carbon materials; [19] 3) tailoring the intermediate adsorption and the intrinsic activity by elemental doping, [20,21] defect engineering, [22] and coating with carbon materials. Sulfur-containing cobalt (hydr)oxide achieved a low overpotential of 0.38 V at 10 mA cm À 2 , a low Tafel slope of 66 mV dec À 1 , and good stability.…”

“…[7][8][9][10] However, the scarcity and the high cost of iridium/ruthenium impede their large-scale utilization in industry. [13,14] Such strategies include, 1) creating nanostructures and reducing the catalyst size to raise the exposure of active sites and the electrochemically active surface area; [15,16] 2) increasing the electric conductivity by coupling the catalyst with conductive compounds like nickel foam, [17] transition metal chalcogenides, [18] and carbon materials; [19] 3) tailoring the intermediate adsorption and the intrinsic activity by elemental doping, [20,21] defect engineering, [22] and coating with carbon materials. [11][12][13] Diverse strategies have been developed to improve the OER performance of transition metal based materials.…”