Excellent plasmon-induced photoelectrochemical properties of WO3/Au nanosheets with uniform dispersion of dense Au nanoparticles fabricated by SILAR method

Abstract

Constructing noble metal-tungsten oxide heterostructure is an effective strategy for extending visible light absorption to longer wavelength owing to the plasmonic effect, thus endowing them with more potential applications in photo(electro)catalysis. Herein, a facile successive ionic layer adsorption and reaction (SILAR) method was developed to fabricate Au NPs decorated WO3 nanosheets (WO3-NSs) electrode for elucidating the mechanism of plasmon-induced charge separation (PICS) and enhancing PICS efficiency. Various characterizations suggested that dense Au NPs with small particle size (<20 nm) were highly dispersed on WO3-NSs by SILAR. The as-prepared WO3/Au electrodes exhibited strong and broad absorption in the visible light region of 500–700 nm, while pristine WO3 electrode had very weak absorption in this region. Anodic photocurrent responses and negative photopotential shifts were observed for WO3/Au electrode, demonstrating that PICS process indeed occurs at the Au-WO3 interface. Beneficial from the good dispersion and high loading amount of Au NPs, as well as formation of large interface between Au NPs and WO3-NSs, the as-prepared WO3/Au electrode achieved satisfactory PICS efficiency. This study paves a new way for the deposition of well-dispersed Au NPs on WO3 photoanodes with excellent PICS-based photoelectrochemical performance.