Photocatalytic activity of silver/silica core–shell nanoparticles for reversible azo-dimerization
The Beijing Key Laboratory for Nano-Photonics and Nano-Structure, Department of Physics, Capital Normal University, 100080, Beijing, China
Accepted: 10 November 2021
Published online: 23 November 2021
Surface-enhanced Raman scattering (SERS) is a promising technique for the study of plasma-driven photocatalytic reactions. It can not only detect the chemical information of probe molecules but also provide a suitable catalytic substrate for surface catalytic reactions. In this paper, SiO2-coated silver nanoparticles (Ag@SiO2) were designed and synthesized, as the photocatalyst for the surface plasmon-enhanced chemical reactions. Driven by the localized surface plasmon resonance (LSPR) over the surface of Ag@SiO2, 4,4′-dimercaptoazobenzene (DMAB) was successfully synthesized by the photocatalytic dimerization of 4-aminothiophenol (PATP) under the excitation of 532 nm laser. The reaction was found reversible under the same experimental conditions. In addition, we designed and synthesized a novel SERS substrate based on Ag@SiO2. Meanwhile, the SERS substrate based on Ag nanofilms (AgNF) also was prepared for comparison. With the same condition excitation laser, Raman signal enhancement effects are different when applying AgNF and Ag@SiO2, which could be attributed to the fact that the inert SiO2 shell eliminates the CE mechanism of the Raman signal. These results provide a simple strategy to figure out the mechanism of the catalytic reaction based on SERS.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021