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.