Active IrO2 and NiO Thin Films Prepared by Atomic Layer Deposition for Oxygen Evolution Reaction

Abstract

Atomic layer deposition (ALD) is a special type of chemical vapor deposition (CVD) technique that can grow uniformed thin films on a substrate through alternate self-limiting surface reactions. Recently, the application of these thin film materials to catalytic systems has begun to attract much attention, and the capacity to deposit these catalytic films in a highly controlled manner continues to gain importance. In this study, IrO2 and NiO thin films (approximately 25 to 60 nm) were deposited on industrial Ni expanded mesh as an anode for alkaline water electrolysis. Different ALD operating parameters such as the total number of deposition cycles, sublimation and deposition temperatures, and precursors pulse and purge lengths were varied to determine their effects on the structure and the electrochemical performance of the thin film materials. Results from the electrochemical tests (6 M KOH, 80 °C, up to 10 kA/m2) showed the catalytic activity of the samples. Oxygen overpotential values (ηO2) were 20 to 60 mV lower than the bare Ni expanded mesh. In summary, the study has demonstrated the feasibility of using the ALD technique to deposit uniformed and electroactive thin films on industrial metallic substrates as anodes for alkaline water electrolysis.

Applications of Atomic Layer Deposition in Design of Systems for Energy Conversion

“…The possibility of an industrial application of IrO 2 (and NiO) deposits prepared by ALD for OER under harsh conditions (6 m KOH, 80 °C, up to 10 kA m −2 ) was studied using industrial expanded Ni mesh as the substrate for the preparation of the anode. [ 93 ] The results indicate good applicability of the process for formation of uniform layers of the oxides with thickness in order of several tens of nm using iridium(III)acetylacetonate, nickel(II) bis(2,2,6,6,‐tetramethyl‐3,5‐heptanedionate), and ozone as the precursors. Although the mass loadings of the noble metal catalysts may be quite low while the catalytic systems still keep their relatively high catalytic activity, a search for cheaper materials is still in progress.…”

Current Status on the Manufacturing of Nanomaterials for Proton Exchange Membrane Energy Systems by Vapor-Based Processes

“…While the ALD method has been shown to be a feasible process for the development of Pt/C catalysts for PEMFCs, additional research has been performed in order to explore its applicability for the development of catalysts for the oxygen evolution reaction that takes place on the anode of the PEMWE. In recent years, research has begun on the development of iridium by ALD for water electrolysis applications. ,− Schlicht et al recently reported they were able to develop an iridium deposition process using ALD. , The authors used ethylcyclopentadienyl-1,3-cyclohexadiene-iridium­(I) ((EtCp)­Ir­(CHD)) as the first precursor material with ozone as the second precursor gas. Working with these precursors and gases, they were able to deposit Ir thin films on anodized aluminum oxide and TiO 2 nanotube supports.…”

Covalently Bonded Ir(IV) on Conducted Blue TiO2 for Efficient Electrocatalytic Oxygen Evolution Reaction in Acid Media

“…Currently published reports that highlight the preparation of both IrO 2 and Ir thin films have been used in the layer deposition method of a single atom. However, this method required H 2 and O 3 gases [19][20][21][22]. Moreover, the set-up cost of the experimental system is high, and the deposition efficiency is low rate [19,20].…”

“…However, this method required H 2 and O 3 gases [19][20][21][22]. Moreover, the set-up cost of the experimental system is high, and the deposition efficiency is low rate [19,20]. Additionally, the small size of metal and metal oxide nanoparticles needs to be investigated due to the chemical and electron properties of nanomaterial structures.…”