Plasma in Liquids induced modification of Cu surfaces

Copper oxide surfaces are commonly used as the catalyst for the CO 2 reduction reaction towards hydrocarbons. However, the lifetime of these catalyst surfaces is limited. In this paper, a method of production of copper oxides through in-liquid plasma is explored, which may be a suitable reactivation method in such applications. The influence of the plasma, ignited in distilled water, with copper and its oxides is monitored in − situ using infrared spectroscopy and ex-situ using scanning electron spectroscop and x-ray photoelectron spectroscopy of the samples. It is shown that the interaction of the plasma with the samples causes a reduction of the copper oxide on a fast time scale and an oxidation on a longer time scale. The formation of preferentially oriented copper nanocubes is observed.