In-situ SERS monitoring of photocatalytic reduction on the surface of large-sized gold nanoparticles solely driven by organic semiconductor

The combination of in-situ SERS monitoring and photocatalysis could track reaction process, and deepen understanding of underlying mechanism of photocatalysis. The study of photocatalytic behavior driven by organic semiconductor is not as clear as plasmonic and inorganic semiconductor photocatalysis. Herein, an organic semiconductor hybrids reactor was constructed by decorating gold nanoparticles (Au NPs). The hybrids achieved in-situ SERS monitoring of photocatalytic degradation of rhodamine 6G with considerable sensitivity and uniformity. This has been attributed to the photocatalytic performance of organic semiconductor and the SERS effect of uniformly modified Au NPs. In particular, the hybrids monitored the photocatalytic reduction of 4-nitrobenzenethiol on its surface by in-situ SERS tracking the formation of intermediate product 4, 4′-dimercaptoazobenzene and end product 4-aminothiophenol. This work introduced organic semiconductor into photocatalysis and in-situ SERS monitoring field for enhancing understanding of the photocatalytic mechanism on organic surface, and developing the application potential of SERS technology.