Facile fabrication and nanostructure control of mesoporous iridium oxide films for efficient electrocatalytic water oxidation

Concisely Synthesized FeNiWOx Film as a Highly Efficient and Robust Catalyst for Electrochemical Water Oxidation

“…Conventionally, OER anodes have been prepared by various physical and chemical techniques, including hydrothermal, 36 electrodeposition, 39,40 electrophoresis, 41−43 spin coating, 44,45 drop-casting, 46 self-assembly, 47 dip coating, 48 screen printing, 49 chemical bath deposition, 50 photochemical formation, 51 and pulsed laser deposition. 19 However, facile and energyconserving preparation techniques of the OER anodes are absolutely needed in view of their extensive availability in a nod to current preparation methods of OER anodes using various physical and chemical techniques.…”

“…Conventionally, OER anodes have been prepared by various physical and chemical techniques, including hydrothermal, electrodeposition, , electrophoresis, − spin coating, , drop-casting, self-assembly, dip coating, screen printing, chemical bath deposition, photochemical formation, and pulsed laser deposition . However, facile and energy-conserving preparation techniques of the OER anodes are absolutely needed in view of their extensive availability in a nod to current preparation methods of OER anodes using various physical and chemical techniques. ,,− Herein, we have amazingly found that loading-controllable single- and mixed-metal oxide films adhered rigidly on various electrode substrates are easily prepared from precursor solutions or suspensions containing corresponding metal salts in methanol/1-methyl imidazole (MeIm) mixed solvents. Material hunting for superior OER anodes has been performed by preparing a variety of single- and mixed-metal oxide films using this method.…”

Redox-State Kinetics in Water-Oxidation IrOx Electrocatalysts Measured by Operando Spectroelectrochemistry

“…Iridium-based oxides exhibit state-of-the-art activity and stability for the oxygen evolution reaction (OER), the step that limits the efficiency of emerging technologies such as proton-exchange membrane (PEM) electrolyzers that convert renewable electricity into chemicals or fuels . In fact, iridium-based oxides are the only stable material with the ability to catalyze O 2 evolution under the acidic conditions of PEM electrolyzers. − To overcome the scalability issues related to the scarcity of iridium, − researchers have focused on improving the OER activity of these materials per iridium atom, developing more porous and amorphous materials such as hydrous iridium oxides (IrO x ). ,− These IrO x materials reach higher OER activities per mass of iridium than crystalline IrO 2 but have lower stability. , The activity of IrO x , however, is difficult to understand because of the highly disordered structure and the complex redox chemistry. For instance, atom probe tomography and electrochemistry–mass spectrometry measurements have recently revealed that more than just the surface and single-metal atoms are involved in redox reactions in OER electrocatalysts, but the relationship between redox states and states driving water oxidation remains elusive. − In this context, operando techniques are a unique way to probe the redox states accumulated under catalytic conditions.…”

Operando spectroelectrochemistry of redox state kinetics in water-oxidation IrOx electrocatalysts

“…1 In fact, iridium-based oxides are the only stable material with the ability to catalyse O2 evolution under the acid conditions of PEM electrolysers. [1][2][3][4][5][6][7][8][9][10] To overcome the scalability issues related to the scarcity of iridium, [11][12][13] researchers have focused on improving the OER activity of these materials per iridium atom, developing more porous and amorphous materials such as hydrous iridium oxides (IrOx). 6,[14][15][16][17][18][19][20] These IrOx materials reach higher OER activities per mass of iridium than crystalline IrO2, but have lower stability.…”