Atomic layer deposition of cobalt phosphate thin films for the oxygen evolution reaction

• Published in: Electrochemistry communications Vol. 98; pp. 73 - 77
• Main Authors: Di Palma, V., Zafeiropoulos, G., Goldsweer, T., Kessels, W.M.M., van de Sanden, M.C.M., Creatore, M., Tsampas, M.N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2019; Elsevier
• Subjects: Atomic layer deposition; Cobalt phosphate; Electrocatalysis; Oxygen evolution reaction; Electrocatalysis; Oxygen evolution reaction; Atomic layer deposition; Cobalt phosphate
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2018.11.021

Electrodeposited cobalt phosphate has been reported as a valid alternative to noble metals as an electrocatalyst for the Oxygen Evolution Reaction (OER). In parallel, Atomic Layer Deposition (ALD) is increasingly being used in (photo)electrocatalytic applications. In this contribution we report on the electrocatalytic activity towards OER of ALD-prepared cobalt phosphate thin films. The selected ALD approach enables tuning of the Co-to-P atomic ratio, which is found to significantly affect the activity of the prepared electrocatalyst. Specifically, concurrently with a Co-to-P ratio increase from 1.6 to 1.9, the current density for OER increases from 1.77 mA/cm2 at 1.8 V vs. RHE (Reversible Hydrogen Electrode) to 2.89 mA/cm2 at 1.8 V vs. RHE. Moreover the sample with a Co-to-P ratio of 1.9 has superior performance when compared to electrodeposited cobalt phosphate thin films reported in the literature.
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•Atomic layer deposited cobalt phosphate as oxygen evolution reaction catalyst.•Chemical composition of cobalt phosphate tuned using ALD supercycle approach•Current density for OER increases with cobalt-to‑phosphorus ratio in the film.•OER current density value of 2.89 mA/cm2 at 1.8 V vs. RHE for CoPiCo-rich sample•Superior performance of CoPiCo-rich compared to electrodeposited cobalt phosphate