Gold electrodes with rough surfaces. The Golden Hedgehog Project

• The tester with two pairs of gold working and counter electrodes was designed.
• One of the pairs underwent amalgamation and then mercury evaporation.
• CV results show at least 20% electrode active surface growth.
• Surface roughening method is simple and technologically relevant.

A simple and technologically relevant way for Au surface roughening based on two physical processes is described: subjecting Au surface to mercury vapors and forming gold amalgamate followed by a thermal decomposition of the amalgamate under vacuum. All mercury is removed yielding the Au surface with numerous spine-like protrusions 2–4 μm high and separated from each other by a few μm. A special tester is prepared with two working Au electrodes and two counter electrodes of which one pair of WE + CE underwent amalgamate roughening (the other pair remained unchanged). Electrochemical measurements show that the tester with the roughened Au electrode has a surface area larger than the tester with untreated Au electrode by 20–160% depending on the method. Advantages of this process in comparison to other methods for Au roughening are briefly discussed.