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

Abstract 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 W 18 O 49 as plasmon antenna was coupled with CdS to form an S‐scheme CdS/W 18 O 49 heterojunction demonstrating photocatalytic H 2 generation activity under a broad‐spectrum light irradiation. Upon exposure to visible light, the CdS/W 18 O 49 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 W 18 O 49 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.