Vertically-aligned Pt-decorated MoS2 nanosheets coated on TiO2 nanotube arrays enable high-efficiency solar-light energy utilization for photocatalysis and self-cleaning SERS devices

The ability to reproducibly create a surface enhanced Raman scattering (SERS) substrate renders an effective means of detecting and degrading organic contaminants. Vertically aligned (VA) nanomaterials have been extensively explored as highly efficient catalysts due to their excellent electron transportability and high concentration of exposed active edge sites. Herein, we report on a ternary ultrafast-electron-transfer heterostructure composed of Pt nanoparticles in-situ grown on VA-MoS2 nanosheet edge sites decorated on TiO2 nanotube arrays (NTAs) (denoted Pt/VA-MoS2/NTAs). Compared with pristine TiO2 NTAs, the Pt/VA-MoS2/NTAs possess a strong resonant SERS effect for detecting rhodamine 6G and an outstanding UV-assisted self-cleaning effect, displaying an excellent photocatalytic performance under visible light irradiation. Such markedly improved performance of the ternary Pt/VA-MoS2/TiO2 NTAs nanocomposites can be attributed to the synergy of catalytic activity of Pt-deposited MoS2 edge sites, the ultrafast electron transfers of VA-MoS2 NS/TiO2 NTAs, and the appropriate band alignment among these three constituents. As such, it represents a robust mean of developing advanced energy utilization nanocomposites for high-performance catalysts and sensors.