Electrodeposition of Cu2O nanocrystalline on TiO2 nanosheet arrays by chronopotentiometry for improvement of photoelectrochemical properties

A nano-sized Cu2O/TiO2 nanosheet arrays (TiO2 NSAs) heterojunction film was fabricating by electrodepositing Cu2O onto TiO2 NSAs using chronopotentiometry. The cyclic alternating current on working electrode is the main contribution to nano-sized Cu2O, which in turn improve the photoelectrochemical properties of the Cu2O/TiO2 NSAs heterojunction film because nano-sized Cu2O, with better electron transfer ability and smaller change transfer resistance in electrolyte, increases the separation and transportation efficiencies of photo-induced electron-hole pairs. Furthermore, electrolyte pH value and deposition current density have significant influence on Cu2O particles size. The results show that the sample prepared with pH = 8 and current density j = 0.25 mA/cm2 exhibits best photoelectrochemical properties because of the smaller sized Cu2O and uniform distribution on TiO2 NSAs.