Light-Induced In Situ Formation of a Nonmetallic Plasmonic MoS2/MoO3–xHeterostructure with Efficient Charge Transfer for CO2Reduction and SERS Detection

Low-cost and abundant reserved nonmetallic plasmonic materials have been regarded as a promising substitute of noble metals for photocatalysis and surface-enhanced Raman scattering (SERS). In this paper, a MoS2/MoO3–xheterostructure was synthesized by light-induced in situ partial oxidation of MoS2nanosheets, exhibiting strong surface plasmon resonance (SPR) in a vis–near-infrared (NIR) region. Continuously plasmon-induced hot electrons boost CO2reduction to CO due to efficient photoelectron injection from MoS2to MoO3–x. Under UV–vis–NIR irradiation, the CO generation rate reached 32.4 μmol g–1h–1with a selectivity of 94.1%, which was much higher than that of single MoS2or MoO3–x. Furthermore, the plasmonic MoS2/MoO3–xheterostructure exhibits superior SERS performance for sensitive rhodamine 6G detection (10–9M) with an enhancement factor of ∼106because of the synergy between SPR and charge transfer effect. This work provides one novel mild synthetization of a plasmonic heterostructure and demonstrates its potential in plasmon-enhanced CO2reduction and SERS detection.