International Journal of Hydrogen Energy, Vol.45, No.38, 19192-19205, 2020
Laser induced formation of copper species over TiO2 nanotubes towards enhanced water splitting performance
We proposed fast and scalable route where the ordered TiO2 nanotubes coated with thin copper layers were annealed by the laser beam of 355 nm wavelength at different fluencies in the range of 15-120 mJ/cm(2). As a result, copper species are integrated with the titania substrate and the formed material exhibits unique optical absorption bands in the visible range. Moreover, X-ray photoelectron spectroscopy analysis reveals the formation of Cu2O while the 4(+) oxidation state of titanium is preserved. According to the electrochemical results, the material treated by laser exhibits outstanding photoelectrochemical activity comparing to the pristine titania or the one only covered by the thin copper film. In particular, when the fluence of 60 mJ/cm(2) was used for the modification of the titania decorated with Cu film, the current density recorded in KOH electrolyte reaches nearly 4.5 mA/cm(2) at +2.0 V vs. Ag/AgCl/0.1 M KCl upon visible light. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.