Destroying the symmetric structure to promote phase transition: Improving the SERS performance and catalytic activity of MoS2 nanoflowers

Semiconductor surface-enhanced Raman scattering (SERS) substrates with excellent stability and uniformity have attracted more and more attention and can theoretically address deficiencies of noble metal. However, a key problem ahead of practical is how to improve sensitivity. Here, we introduce a metal-free, Ni-doped MoS2 nanoflowers (NFs) as SERS substrates with a significant enhancement factor of 3.56 x 10(5). This remarkable enhancement is attributed to three factors: (1) 1 T-2 H mixed-phase provides more electrons, significantly improved the charge transfer process and electromagnetic enhancement; (2) Ni doping improves the polarity of MoS2 NFs and enhances the interface dipole-dipole interaction with MB molecules; (3) increases the specific surface area of MoS2 NFs enabled sufficient interaction with the Methylene blue (MB) molecules. The Ni-doped MoS2 NFs was used to detect pollutants such as bilirubin, which shows super sensitive SERS activity with the detection limit as low as 10(-7) M. Moreover, this substrate has excellent stability and uniformity. Importantly, Ni doped MoS2 NFs also exhibits excellent catalytic activity. We believe that this research will not only help promote the application of MoS2 NFs for biosensor application but also provide help for understanding the enhancement mechanism of semiconductors as SERS substrates. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A metal-free, Ni-doped MoS2 nanoflowers (NFs) as SERS substrates with a significant enhancement factor were introduced, with remarkable enhancement attributed to factors such as more electrons, improved charge transfer and electromagnetic enhancement, enhanced interface interactions with molecules, and increased specific surface area. The substrate showed super sensitive SERS activity with excellent stability and catalytic activity, promoting the application of MoS2 NFs for biosensors and enhancing understanding of semiconductor enhancement mechanisms as SERS substrates.