Detection and degradation of environmental pollutants based on Fe_3O_4@Au nanoparticles as surface enhanced Raman scattering (SERS) substrates

摘要

Ever since the surface-enhanced Raman scattering (SERS) effect was discovered, it has played a significant role in the field of vibrational spectroscopy and is now finding increasing use in high-profile applications. Recently, many catalytic-active SERS substrates have been developed for in situ monitoring of environmental pollutants, which could provide new insights into the kinetics and mechanism of catalysis. Herein we developed a recycable SERS substrate with Fe_3O_4 and Au constituents, which can also be used as active photocatalyst. Nitroaromatic compounds were chosen as the target pollutants due to their toxic and mutagenic effects towards organisms. The morphology and structure of Fe_3O_4@Au were characterized by multiple complimentary techniques including transmission electron microscopy, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometry analysis. Under visible light or UV irradiation, the reduction of the nitro-group to amino-group was identified by observing the spectroscopic changes. The result indicates that the adsorption of nitroaromatic compounds on Fe_3O_4@Au substrate occurs via the nitro-group. Our study could extend the SERS application to the photodegradation monitor of environmental pollutants containing nitro-group.