Oxygen Vacancies Induced Plasmonic Effect for Realizing Broad-Spectrum-Driven Photocatalytic H2 Evolution over an S-Scheme CdS/W18O49 Heterojunction

Broad-spectrum-driven photocatalysis remains a challenging pursuit for light-chemical energy conversion. Integrating plasmonic nanostructures with localized surface plasmon resonance (LSPR) effect as light absorber onto photocatalyst can realize broad spectral response as well as promote light to energy conversion. Herein, oxygen-vacancy-rich W18O49 as plasmon antenna was coupled with CdS to form an S-scheme CdS/W18O49 heterojunction demonstrating photocatalytic H-2 generation activity under a broad-spectrum light irradiation. Upon exposure to visible light, the CdS/W18O49 heterojunction illustrates the best photocatalytic H-2 generation rate of 5.9 mmol g(-1) h(-1), which is 2.6 times higher than CdS; and its external quantum efficiency achieves 0.17% and 0.05% at 550 and 650 nm, respectively. This activity enhancement is attributed to the enhanced light-harvesting ability and faster charge separation induced by the LSPR effect of the W18O49 plasmon with rich oxygen vacancies and S-scheme transfer mechanism. This work will be beneficial to develop non-metal plasmons assisted broad-spectrum-response photocatalysts.

Automated summary

Integrating oxygen-vacancy-rich W18O49 as a plasmon antenna with CdS can enhance the photocatalytic H-2 generation activity under visible light, achieving a higher efficiency compared to CdS alone. This enhancement is attributed to the improved light-harvesting ability and faster charge separation caused by the LSPR effect of W18O49 plasmon with rich oxygen vacancies and an S-scheme transfer mechanism.