Enhanced plasmonic photoelectrochemical response of Au sandwiched WO3 photoanodes

•Plasmonic Au nanoparticles and WO3 in different configurations were prepared by electrochemical approaches.•The Au/WO3/Au photoanode showed the highest photocurrent generation at a higher bias potential.•The FTO/WO3/Au photoanode exhibited the highest ABPE conversion efficiency.

Herein we present a plasmonic sandwich photoelectrode design utilizing Au nanoparticles and WO3 for the photoelectrochemical process. The plasmonic layer of Au nanoparticles was electrodeposited onto WO3 photoanodes in different configurations to enhance the photocurrent generation of the WO3 photoanodes during photoelectrochemical reaction. The photoanodes were characterized by field emission scanning electron microscopy (FESEM), UV-Vis spectroscopy and photoelectrochemical analysis. It is found that the photoanodes with plasmonic layers showed a higher photocurrent density in comparison to pristine WO3. The improvement in photocurrent generation can be attributed to the plasmonic effect from the Au nanoparticles. Furthermore, the Au/WO3/Au photoanode generated the highest photocurrent among the samples at high bias potential. However, based on the ABPE conversion efficiency, the plasmonic Au as surface layer is the most promising configuration as photoanode.

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