Photoelectrochemical water splitting with 600 keV N2+ ion irradiated BiVO4 and BiVO4/Au photoanodes

Low energy N2+ ion beam with 600 keV energy has been used to irradiate BiVO4 and Au nanoparticles loaded BiVO4 (BiVO4/Au) thin films deposited over fluorine doped tin oxide substrates via spray pyrolysis technique. Ion irradiation results in tailoring the optical, electrical, and morphological properties of the thin films and thence also responsible for changes in electrochemical properties. The scanning electron microscope images reveal the evolution of Au nanoparticles after irradiation at 2 x 10(15) fluence to a nanourchins type of morphology. In consequence of morphological changes, the signature of surface plasmon resonance peak exhibited by Au nanoparticles in BiVO4/Au shows improvement. An increase of approximately 92% in photocurrent density in comparison to pristine BiVO4 has been found after irradiation in BiVO4/Au photoanode at 2 x 10(15) ions/cm(2) fluence. Moreover, irradiation also aids in improving photoelectrochemical response of BiVO4 photo anodes without Au nanoparticles. The enhancement can be attributed to the notable changes in onset potential, charge separation, charge transfer resistance and optical properties. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.