Hi Charmaine,

What you can try is to sputter the oxidized layer by using noble gas e.g. with He+ for low etch rates or Ar+ for higher etch rates. You can look for broad beam low energy ion sputtering.

regards

Erik

Plasma cleaning is best for it. You can try hydrogen or HF plasma cleaning.

In chemical cleaning , you can use (20 ml HBr + 0.05 ml H2O2 ) solution.

In a chemical[1] cleaning you might be interested to use EIS (1Hz, 1MHz) as a tool[2,3] to probe, figure out or/and verify, in situ, learning how fast and strong might be (more efficient) your cleaning process.

1. For other cleaning processes you can, also, use EIS, (before and) after cleaning, as a lateral tool to figure out, ex situ, how helpful was your cleaning process.

2. Characterisation of the electrochemical redox behaviour of Pt electrodes by potentiodynamic electrochemical impedance spectroscopy https://link.springer.com/content/pdf/10.1007%2Fs10008-008-0663-7.pdf

3. EIS analysis of oxygen reduction reaction of Pt supported on different substrates https://www.sciencedirect.com/science/article/pii/S0360319917333335

Electrochemical cleaning of Pt electrode:

http://courses.chem.psu.edu/chem524/Pt_electrode_expt0.pdf