Electrodeposition of Cu2O Nanostructure on 3D Cu Micro-Cone Arrays as Photocathode for Photoelectrochemical Water Reduction

Abstract

The increased utilization ratio of solar energy by a PEC cell, which is significant in meeting the ever increasing demand of clean fuels and energy can be realized by fabricating the device into three dimensional structure. In this work, micrometer size Cu cone arrays was introduced to combine with electrodeposited Cu2O in the fabrication of photocathode. The acquired 3D Cu2O/Cu micro-cone arrays was proven to be more photoactive than the planar Cu2O/Cu foil structure. Under AM 1.5 illumination, the photocurrent density generated by the bare Cu2O/Cu micro-cone arrays reached a plateau value of −3.25 mA cm−2 in the linear sweep voltammetry test conducted from positive to negative. When protected by 20 nm ZnO plus 10 nm TiO2, the 3D photocathodes presented better stability and maintained a relatively large photocurrent at the same time. Thus, we have proposed a new structure in micrometer size that can improve the property of Cu2O photoelectrode.