Localized electrodeposition of praseodymium oxide on boron-doped diamond

The deposition of praseodymium oxide (PrO₂) films on diamond electrodes is of interest for electrochemical applications, because of the catalytic and permselective properties of this material. In this work, PrO₂ was deposited on commercial boron-doped diamond (BDD) electrodes from solutions of praseodymium nitrate in hydrogen peroxide, where a local increase of pH at the electrode surface is used to precipitate hydrated praseodymium oxide at the solution-electrode interface. For particular deposition conditions, it is observed that pronounced lateral heterogeneities are seen in the observed deposition rate, arising from lateral fluctuations in the electrochemical activity of the diamond electrodes used. It is also observed that the use of scanning electrochemical techniques enables oxide deposition with good spatial control to be achieved.