Nanosecond and microsecond-pulsed plasma-in-liquid treated copper oxide surfaces

TL;DR

This study investigates how nanosecond and microsecond plasma-in-liquid systems can modify copper oxide surfaces in situ, producing Cu2O nanocubes that serve as catalysts for electrochemical CO2 conversion, with nanosecond plasma being more efficient.

Contribution

It demonstrates a novel plasma-based method to regenerate copper oxide surfaces and produce Cu2O nanocubes for catalysis, comparing nanosecond and microsecond plasma excitation schemes.

Findings

Nanosecond plasma produces more H2O2 than microsecond plasma.

Cu2O nanocubes are formed on the surface after plasma treatment.

The plasma-treated surfaces are characterized by electron microscopy and electrochemical tests.

Abstract

Nanosecond and microsecond plasma-in liquid systems are explored to oxidize or regenerate a copper oxide surface in situ to serve as a catalyst for electrochemical CO$_2$ conversion. The plasma excitation generates H$_2$O$_2$ in the liquid, which induces the dissolution of Cu into Cu(OH)$_2$ and the recrystallization into Cu$_2$O nanocubes at the interface. The plasma performance of the two excitation schemes is analyzed, showing that the H$_2$O$_2$ production of nanosecond plasma is more efficient than of microsecond plasmas. The nature of the Cu$_2$O nanocubes is evaluated using electron microscopy and electrochemical characterization.