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.