Interface Design of 3D Flower-like Ag@ZnSe Composites: SERS and Photocatalytic Performance

Abstract

In this work, we cosputtered Ag and ZnSe on a polystyrene template to form a three-dimensional (3D) Ag@ZnSe (x) structure. The 3D surface morphology and material composition that provided abundant "hot spots" were controlled by adjusting the sputtering power of the ZnSe, which was confirmed by finite-difference time-domain (FDTD) simulation. The introduction of ZnSe into the noble metal Ag also introduced a charge-transfer (CT) effect into the system, and the CT path was proven with the two-dimensional correlation spectroscopy (2D-COS)-surface-enhanced Raman scattering (SERS) technique. In addition, the substrate exhibited excellent catalytic activity due to the CT effect. The catalyzed degradation of malachite green (MG) was due to the CT effect in the system, and the catalytic process was successfully monitored by in situ SERS. Most importantly, the catalytic degradation by Ag@ZnSe (x) with different parameters was proportional to the degree of CT (ρ CT ). The SERS and catalytic mechanisms were analyzed in depth with the 2D-COS-SERS technique, which was also useful in verifying the CT process. The catalytic sites for MG were successfully monitored with the 2D-COS-SERS technique. This study provides a reference for studies of the synergistic effects of the electromagnetic mechanism and CT, as well as a new perspective on photocatalysis with dye molecules and monitoring of the catalytic processes.

Noble metal-free SERS: mechanisms and applications

“…5,6 The synergy of the extremely high sensitivity offered by plasmonic nanomaterials, the inherent structural specificity of Raman spectra, and the experimental versatility of SERS has made SERS an exceptionally powerful analytical technique. 7,8 Although SERS has grown into a rich field of research and technology in the decades since its discovery, continued efforts are needed to achieve the goals of routine use in analytical and commercial products. For practical application, a SERS-active substrate should be homogeneous, reproducible, cost-effective, and easy to fabricate.…”

Porous rod-shaped Fe2O3/Ag/BP: a novel substrate for highly sensitive SERS detection of persistent organic pollutants

“…Under nature light irradiation, Ag NPs were excited due to the plasma resonance. Photoexcited electrons migrated from the surface of Ag NPs to the conduction band of Fe 2 O 3 , which was a narrow band gap semiconductor [67][68][69]. Besides, the unique porous structure of Fe 2 O 3 also provided more tiny gaps that could generate 'hot spots' and enhance the SERS activity of the substrate, which greatly enhanced the SERS activity from the EM [26].…”

3D Flower-like Composites in Energy Storage and Photocatalytic Applications: A Review

“…The 3D flower like structure with high specific surface area and more electroactive sites in the 3D flower like Ag@ZnO composite improves the cell efficiency. The high electrochemical performance was attributed to the unique flower like structure and the Ag-additive [127][128][129].…”