Synthesis of novel Cu2O micro/nanostructural photocathode for solar water splitting

The hierarchical p-type Cu2O micro/nanostructural film on copper foil is successfully fabricated via a facile and cost-effective template route through transformation of lotus-like CuO/Cu(OH)(2) nanosheet/nanowire structure for photoelectrochemical (PEC) hydrogen generation. Various size of Cu2O micro/nanostructure transfers from CuO nanosheets and Cu(OH)(2) nanowires by means of thermally reducing the oxides from Cu2+ to Cu1+ at temperature of 500 degrees C under nitrogen atmosphere. Mott-Schottky plot shows the flat band potential of the hierarchical Cu2O film to be -0.17 V vs. Ag/AgCl and a hole concentration of 5.7 x 10(19) cm(-3). Direct band gap of 2.03 eV in Cu2O film is determined via incident photon-to-electron conversion efficiency measurement. Significantly, this Cu2O hierarchical photocathode exhibits remarkable photocurrent of -1.6 mA cm(-2) at a potential of -0.6V vs. Ag/AgCl, corresponding to the solar conversion efficiency of 1.97%. These results demonstrate the Cu2O micro/nanostructural film have great potential in solar hydrogen applications. Crown Copyright (c) 2013 Published by Elsevier Ltd. All rights reserved.