Fe3O4@m-ZrO2@Ag ternary magnetic nanocomposites for sensitive SERS sensing and photocatalytic removal of Cr(VI) and organic dyes

In this study, a crystalline mesoporous ZrO 2 interlayer allowing for enrichment capability and photocatalytic activity was introduced to develop a novel magnetic Fe 3 O 4 /m-ZrO 2 /Ag nanocomposite combined with excellent SERS activity and photocatalytic property. The coverage of Ag nanoparticles on Fe 3 O 4 /m-ZrO 2 /Ag was well controlled to tune their SERS sensitivity by varying the feed amount of AgNO 3 . Several characterization methods were utilized to investigate their composition, morphology and crystal structure. The SERS experiments demonstrated Fe 3 O 4 /m-ZrO 2 /Ag nanocomposites possessed markedly SERS sensitivity, exceptional signal reproducibility and excellent storing stability. They could sense R6G and Cr (VI) at the concentrations of 10 −9 and 5 × 10 −8  M, respectively. Beyond that, the Fe 3 O 4 /m-ZrO 2 /Ag nanocomposites effectively accomplished recyclable detecting R6G and Cr (VI) in 5 cycles through facile photocatalytic removal of pollutants under UV irradiation. Altogether, the novel Fe 3 O 4 /m-ZrO 2 /Ag nanocomposites prepared in this study have high SERS sensitivity and good photocatalytic performance, which is of great significance for environmental detection and ecological restoration.