Enhanced photoelectrochemical water splitting by oxides heterojunction photocathode coupled with Ag

A novel one-dimensional Co₃O₄/CuO/Ag composite structure film was directly grown on indium tin oxide glass substrate by a simple hydrothermal method and electrodeposition method. The film was employed for the first time as a photocathode for photoelectrochemical (PEC) water splitting to generate hydrogen. The photocurrent density of the Co₃O₄/CuO/Ag composite structure achieved -5.13 mA cm^-2 at -0.2 V vs. RHE, which is roughly 12.8 times that of 1D Co₃O₄ nanowires and 3.31 times Co₃O₄/CuO heterojunction photocathodes. The enhanced PEC performance of this Co₃O₄/CuO/Ag composite structure ascribes increased light-harvesting and light-absorption, distensible photoresponse range, decreased interface charge transfer resistance, and improved photogenerated electron-hole pairs transfer and separation.