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The design of photocatalyst with excellent light-harvesting and charge-separation abilities is quite important for high-performance photocatalysis. Herein, narrow-bandgap PbS, wide-bandgap WO3–x, and Au nanoparticles were combined to form a plasmon-mediated Z-scheme nanostructure for the first time. Particularly, PbS nanoparticles were deposited on oxygen-abundant WO3–x nanobricks, then Au nanoparticles were grown on the hybrids to form WO3–x/PbS/Au ternary nanostructures. Because of the cooperation of wide and narrow bandgaps as well as the oxygen vacancies and plasmon, the ternary hybrids displayed wide light absorption ranging from ultraviolet to near-infrared region. Meanwhile, the energy band arrangement of PbS and WO3–x provides a direct Z-scheme pathway and built-in electric field for charge transfer and separation. As a result, WO3–x/PbS hybrids displayed a large enhancement on photocatalytic hydrogen generation activity compared with the components under visible light irradiation, which is 9.2 and 9.8 times of WO3–x and PbS, respectively. Furthermore, the WO3–x/PbS/Au ternary hybrids showed the best photocatalytic performance that is 21.8 and 2.4 times of WO3–x and WO3–x/PbS hybrids. Meanwhile, the ternary photocatalysts possessed prominent apparent quantum efficiency under near-infrared light irradiation. The prominent photocatalytic performance can be attributed to the broadband light absorption, enhanced specific surface area, efficient charge transfer and separation induced by the oxygen-vacancy and plasmon-mediated Z-scheme band energy structure. [ABSTRACT FROM AUTHOR]

Metal/semiconductor hybrids show potential application in fields of surface-enhanced Raman spectroscopy (SERS) and photocatalysis due to their excellent light absorption, electric field, and charge-transfer properties. Herein, a WO 3 -Au metal/semiconductor hybrid, which was a WO 3 nanobrick decorated with Au nanoparticles, was prepared via a facile hydrothermal method. The WO 3 -Au hybrids show excellent visible light absorption, strong plasmon coupling, high-performance SERS, and good photocatalytic activity. In particular, on sensing rhodamine B (RhB) under 532 nm excitation, bare WO 3 nanobricks have a Raman enhancement factor of 2.0 × 10 6 and a limit of detection of 10 -8 M due to the charger-transfer property and abundant oxygen vacancies. WO 3 -Au metal/semiconductor hybrids display a largely improved Raman enhancement factor compared to pure Au and WO 3 components owing to the synergistic effect of electromagnetic enhancement and charge transfer. The Raman enhancement factor and limit of detection are further improved, reaching 5.3 × 10 8 and 10 -12 M, respectively, on increasing the content of Au to 2.1 wt %, owing to the strong plasmon coupling between the Au nanoparticles. Additionally, the WO 3 -Au hybrids also exhibit excellent photocatalytic activity toward degradation of RhB under visible light irradiation. WO 3 -Au (2.1 wt %) possesses the fastest photocatalytic rate, which is 6.1 and 2.0 times that of pure WO 3 nanobricks and commercial P25, respectively. The enhanced photocatalytic activity is attributed to the strong plasmon coupling and the efficient charge transfer between Au and WO 3 nanobricks. The as-prepared materials show great potential in detecting and degrading pollutants in environmental treatment., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)