Photoelectrochemical CO2 reduction on CuO-Cu2O nanocomposites with noble metal co-catalysts enhances the production of C1 oxygenates and acetate

Identifier:  imarina:9475695

Handle: https://hdl.handle.net/20.500.11797/imarina9475695

Authors:  Yazdely, Tahereh Mokary; Garcia-Valls, Ricard; Puga, Alberto

Abstract:
Multi-junction copper oxide nanocomposite photocathodes formed by CuO nanowire arrays coated with Cu2O nanopyramids or stacked nanoprisms, i.e. CuO(NWA)|Cu2O(NPy), exhibit remarkable electrochemical stability toward reductive corrosion. Whilst bare CuO nanowires are extremely prone to decomposition even at the mildest potentials applied, the core@shell morphology of CuO(NWA)|Cu2O(NPy) resists cathodic potentials up to -0.7 V (vs. AgCl/Ag). Precisely controlled electrodeposition of silver or gold nanoparticles resulted in Ag nanotrails arranged on flatter surface regions in CuO(NWA)|Cu2O(NPy)|Ag, whereas Au nanoaggregates were deposited on both flat areas and prominent apexes in CuO(NWA)|Cu2O(NPy)|Au. Photocurrent measurements demonstrated redox process activation, namely above three-fold current density increases, by light for CuO (NWA)|Cu2O(NPy). The participation of CO2 in them was also confirmed by around 70 % photocurrent increases (higher than 0.2 mA cm- 2) and by sensibly milder cathodic potential onsets (