Potent n-type nanostructured cruciate flower-like Cu/Cu2O films for photocathodic protection

Various approaches have been developed to enhance n-type Cu2O photoelectrochemical activity. This study introduced a simple method of tuning electronic structure through adjusting solution pH when electrodeposition of Cu2O films on FTO substrate. Combined surface analysis showed that the Cu2O films presented gradual change cruciate flower-like nanostructure and hybrided with metallic copper. The Cu/Cu2O films presented a visible light response and the band gap could be effectively decreased by increasing the deposition solution pH. The photoelectrochemical cathodic protection performance of the films was studied. The electrode potential of 304 stainless steel by coupling with the Cu/Cu2O films (deposited at pH 5) reached the most negative photopotential shift of 179 mV under illumination. The related photocurrent density was 0.12 mA/cm(2) . This enhanced photoelectrochemical performance was evidenced by both direct excitation of Cu2O and the surface plasmon resonance effects of Cu upon illumination.