Modification of a photoanode by means of localized surface plasmon resonance from Au nanoparticles decorated on ZnO nanorods for photoelectrochemical applications

Photoelectrochemical (PEC) activity is possibly enhanced by an increase in photocurrent generated from the photoanode. In this work, a modified photoanode that consists of zinc oxide nanorods (ZnO-NRs) decorated with gold nanoparticles (Au-NPs) is proposed to improve the generation of photocurrent. X-ray diffraction and scanning electron microscopy are employed to confirm the decoration of Au-NPs on well-aligned ZnO-NRs. A significant enhancement (∼4 times) in photocurrent density is obtained from the ZnO-NR photoanode decorated with Au-NPs compared to the bare ZnO-NR photoanode. Photoluminescence and UV-visible spectroscopy reveal that the improvement in photocurrent density results from (i) the decrease in charge recombination in the ZnO-NRs due to charge dissociation and (ii) the additional injection of charge from Au-NPs owing to localized surface plasmon resonance. This research presents the idea of taking the benefit from Au-NPs to enhance the photocurrent density in PEC applications through the decrease in charge recombination and the increase in charge injection.

Citation

Japanese Journal of Applied Physics, 58(SD), 2019