Illuminating nanostructured gold electrode: surface plasmons or electron ejection?

Recently, the photoelectric effect in metals in electrolyte environments has aroused the interest of researchers. However, direct evidence for surface plasmons-enhanced electrochemical reactions involving classic outer-sphere reactions of reversible redox couples is seldom reported. We used a surface plasmons-active gold-mushroom-array as a working electrode and observed enhanced faradaic current from ferrocenemethanol following illumination with a xenon lamp. The photoelectric current behaved differently in the presence and absence of oxygen in the solution. The preliminary results are discussed with consideration of the possible mechanisms of electron transfer, although they are very complex, due to the lack of direct evidence. Some consideration was also taken of the research on photoelectrochemical reactions on metallic electrodes.