Plasmonic enhanced Cu(2)O-Au-BFO photocathodes for solar hydrogen production

A novel Cu(2)O-Au-BFO heterostructure photocathode was constructed which significantly improved the efficiency of photo-generated carrier transfer for solar hydrogen production. A BiFeO(3) (BFO) ferroelectric film was synthesized on top of a Cu(2)O layer by a sputtering process. The BFO layer acted to protect the Cu(2)O layer from photochemical corrosion, increasing photoelectrochemical (PEC) stability. The p–n heterojunction between Cu(2)O and BFO layers enhanced the PEC properties by suppressing charge recombination and improved interfacial charge transfer efficiency. When Cu(2)O and BFO are interfaced by Au Nanoparticles (NPs) the PEC performance was further enhanced, due to hot-electron transfer at the plasmonic resonance. After positive poling, the depolarization field across the whole volume of BFO film drove electrons into the electrolyte solution, inducing a significant anodic shift, V(op) of 1.01 V vs. RHE, together with a significantly enhanced photocurrent density of −91 μA/cm(2) at 0 V vs. RHE under 100 mW/cm(2) illumination. The mechanism was investigated through experimental and theoretivcal calculations.