CuO/Cu Nanoparticles via Non-thermal Atmospheric Plasma for Photoelectrochemical Water-Splitting Application

This article discusses an interesting method to synthesize copper oxide films on a copper foil for photoelectrochemical (PEC) water-splitting applications. A simple, and low-cost, non-thermal plasma (NTP) jet on a copper foil with an Ar/O 2 gas mixture in ambient air are used. The NTP exposure times used to synthesize the CuO films on Cu foil were 10 s, 20 s, and 30 s. The prepared films were subjected to different apparatus and techniques. X-ray diffraction tests showed that the prepared films were polycrystalline with sharp peaks. Field-emission scanning electron microscopy (FE-SEM) revealed the morphology of the modified surface of the CuO films, the images showing that the films consist of homogeneous and well-distributed nanoparticles. These films were a photocathode using a three-electrode homemade Teflon PEC with a quartz window and a Keithley-2430 source meter. An increased photocurrent was obtained via water-splitting under full-spectrum xenon light with a photoconversion efficiency of up to 6.45%. The increased PEC water splitting was mostly due to the creation of many electron–hole pairs. This research could pave the way for a more efficient CuO-based photocathode for PEC. Graphic Abstract