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

Abstract A nano-sized Cu 2 O/TiO 2 nanosheet arrays (TiO 2 NSAs) heterojunction film was fabricating by electrodepositing Cu 2 O onto TiO 2 NSAs using chronopotentiometry. The cyclic alternating current on working electrode is the main contribution to nano-sized Cu 2 O, which in turn improve the photoelectrochemical properties of the Cu 2 O/TiO 2 NSAs heterojunction film because nano-sized Cu 2 O, 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 Cu 2 O particles size. The results show that the sample prepared with pH = 8 and current density j  = 0.25 mA/cm 2 exhibits best photoelectrochemical properties because of the smaller sized Cu 2 O and uniform distribution on TiO 2 NSAs.