Enhanced photoelectrochemical processes by interface engineering, using Cu2O nanorods

• Pure Cu2O nanorod arrays were fabricated through anodization of Cu foil.
• The surface of bulk crystalline Cu2O modified with nanorods.
• The nanorod/bulk Cu2O electrodes show enhanced photoelectrochemical behavior.

Here in this research, we report on surface engineering of bulk Cu2O photocathode thorough employing nanostructured materials. Nanorods (NRs) of copper oxide with average lengths of 150 nm have been synthesized by anodization of Cu foil in aqueous KOH electrolyte, followed by annealing treatment. Several heating processes were examined to reach pure Cu2O nanostructures and lastly the moderate annealing procedure at 700 °C under Ar gas flow resulted in pure Cu2O nanostructures, confirmed by XRD analysis. Surface modified nanorod/bulk Cu2O electrode was prepared by spin coating of sediments suspension of anodized drop on bulk Cu2O film fabricated through thermal oxidation method, followed by final heating process. Photoelectrochemical analysis indicates that nanorod/bulk Cu2O electrodes have noticeable enhancement in photocurrent, around 76% at −0.6 V and the favorable decrease in interface resistance about 103 Ω in comparison to the bulk Cu2O thermal oxidized electrode. This novel bulk Cu2O electrode with modified nanostructured surface can be a good candidate as the electrode of either photoelectrochemical systems for hydrogen generation or the photocathode of bulk heterojunction photovoltaic cells.