Direct observation of p,p′‐dimercaptoazobenzene produced from p‐aminothiophenol and p‐nitrothiophenol on Cu₂O nanoparticles by surface‐enhanced Raman spectroscopy

Abstract

Surface-enhanced Raman scattering of p-aminothiophenol and p-nitrothiophenol were obtained on the surface of Cu 2 O nanoparticles, showing novel spectral changes with morphology-dependent and time-dependent characteristics. The measured Raman signals were believed to partly originate from the newly produced surface species p,p′-dimercaptoazobenzene. The nature of surface chemisorption status during Raman measurement was investigated experimentally and theoretically via combined surface-enhanced Raman scattering and density functional theory study, indicating that surface catalytic reaction of p-aminothiophenol and p-nitrothiophenol could take place on the surface of oxide nanostructures as well as coinage metal material.

Facet‐Controlled Synthetic Strategy of Cu2O‐Based Crystals for Catalysis and Sensing

“…In this context, the inexpensive, non‐toxic and abundantly available Cu 2 O nanomaterials, with unique optical and electrical properties, have recently aroused general attention, due to their outstanding morphology‐dependent applications in catalysis (gas oxidation, CO 2 reduction, organocatalysis, electrocatalysis, and photocatalysis, sensing (gas sensors, ion detection, and surface‐enhanced Raman scattering (SERS), as adsorbents, biotoxicity, as chemical templates and energy‐related processes (water splitting, solar energy conversion and lithium‐ion batteries. Compared to Cu 2 O nanowires or nanorods, nanospheres, hollow structures, self‐assembled superstructures, and Cu 2 O polyhedra enclosed by high‐index planes, the preparatio...…”

Effect of Intermolecular Distance on Surface-Plasmon-Assisted Catalysis

“…These three strong peaks were once considered to be the b2 enhancement mode of PATP but were finally proven to be the characteristic Raman peaks of DMAB following PATP coupling . These three peaks are now widely used as an indicator of surface-plasmon-assisted catalysis (DMAB formation) due to their very high Raman intensity and good discrimination. − …”

“…Raman mapping spectroscopy is an ideal technique for studying the distribution of matter. − To investigate the effect of PATP-Ag spacing on the coupling reaction with the aid of plasmids, different concentrations of PATP and APDS were subjected to Raman mapping spectroscopy testing under the same experimental conditions, and the results were compared. It can be seen from Figure c that the band at 1432 cm –1 is the strongest in the Raman spectrum of DMAB.…”

Noble Metal Free, Visible Light Driven Photocatalysis Using TiO2 Nanotube Arrays Sensitized by P‐Doped C3N4 Quantum Dots

“…Recently plasmonic materials coupled with semiconductor or graphenic materials has shown wide potential in plasmon‐exciton (collectively called “plexciton”) co‐driven surface catalytic reaction due to a synergistic improvement in plasmon‐to‐electron conversion efficiency . In this venture, plasmonic nanoparticles (NPs) integrated with semiconductor photocatalysts such as Cu 2 O, MoS 2 , TiO 2 ,50b,51 graphitic carbon nitride (g‐C 3 N 4 ), doped and undoped graphene,53d,57 etc. have been explored for the surface photocatalytic conversion of aromatic thiols into azo compounds .…”