Stable Cu2O/TiO2 nanorod photoelectrodes for enhanced photoelectrochemical water splitting in ethanol-assisted systems

The heterojunction of the Cu 2 O/TiO 2 nanorod photoelectrode was synthesized via a facile hydrothermal method and electrodeposition method. The influence of Cu 2 O deposition on the structural, optical, and photoelectrochemical properties of the photoelectrodes was systematically investigated through comprehensive physicochemical characterization. Under AM 1.5 simulated solar illumination, the optimized Cu 2 O/TiO 2 nanorod photoelectrodes achieved a photocurrent density of 1.30 mA cm −2 at 1.23 V vs. RHE in an ethanol-containing electrolyte. The enhanced photoelectrochemical performance was attributed to improved light utilization and more efficient charge separation with suppressed electron-hole recombination resulting from the formation of the Cu 2 O/TiO 2 heterojunction. Simultaneously, ethanol also served as a sacrificial electron donor in the proposed system. Notably, the Cu 2 O/TiO 2 nanorod photoelectrodes can be promising photoelectrodes for solar-driven hydrogen production with a simple, economical, and environmentally friendly approach.