Influence of deposition potential on the photoelectrochemical cathodic protection behavior of n-type Cu@Cu2O films

摘要

Cu@Cu2O films were prepared by electrochemical deposition method. The obtained Cu@Cu2O films were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), confocal Raman spectroscopy (CRS), UV-visible absorption spectroscopy and Photoluminescence (PL) spectroscopy. Electrochemical measurements were performed under intermittent visible light illumination to assess the photoelectrochemical cathodic protection effect of the prepared Cu@Cu2O films. The results indicated that a lower deposition potential could facilitate the reduction of Cu2O grain size together with an increase number of Cu. But the deposition potential has no obvious influence on the band-gap of the composite films, which exhibited n-type semiconductor properties. The open circuit potential of 304 stainless steel by coupling with the Cu@Cu2O-0.3 V films presented the most negative shift of -179 mV under visible-light illumination. The related photocurrent density was 0.13 mA.cm-2. The photoelectrochemical conversion mechanism and the photoelectrochemical cathodic protection effects of the Cu@Cu2O films were discussed in detail.