Influence of the Substrate on the Performance of a Co-Prussian Blue Catalyst towards the Water Oxidation under Mild Conditions

Abstract

Efforts in developing water oxidation reaction (WOR) catalysts mainly focus on Earth-abundant elements with high stability and efficiency. However, the behavior of these materials may vary depending on the electrochemical substrate with which they interact. Understanding the interaction between the catalyst and the substrate can provide valuable insights to advance the design of highly efficient water-splitting devices. In this context, we investigated the influence of different electrochemical substrates on the performance of cobalt-Prussian blue analog (Co-PBA) in WOR under neutral conditions (pH = 7). The results highlight the role of substrate type, including conductive glass (fluorine-doped tin oxide (FTO)), 3D-printed electrodes (3DPE), and Ni-foam, on the electrocatalytic efficiency of Co-PBA. Two methods of Co-PBA synthesis (electrodeposition and drop casting) were employed to understand their effects on morphology, electrochemical properties, and performance in WOR. The results revealed that the substrate and preparation method of Co-PBA can affect the electrochemical behavior, demonstrating differences in electrocatalytic activity, stability, and charge transfer.