LAUSR

Abstract Exposure to hexavalent chromium [Cr(VI)] poses a serious health threat. Thus, accurate field analysis and efficient Cr(VI) reduction are of great importance. The motivation of this research was to synthesize a multifunctional satellite Fe3O4-Au@TiO2 nano-structure for surface enhanced Raman scattering (SERS) detection and photo-reduction of Cr(VI). Our experimental results and three-dimensional finite difference time domain (FDTD) simulation suggest that coating Fe3O4@Au with a TiO2 layer 2–6 nm thick can protect SERS substrates from direct contact and reaction with Cr(VI), as well as enrich Cr(VI) in close proximity to Au NPs to facilitate its SERS detection. The SERS response exhibited a concentration dependence up to 5 μM with a detection limit of 0.05 μM. The SERS substrate exhibited an excellent selectivity for Cr(VI) over other coexisting ions and resulted in a satisfactory quantitation in complicated environmental matrices. In addition, the Cr(VI) reduction photo-catalyzed using this multifunctional material followed the first-order kinetics and the reduction process was monitored in situ with the SERS effect, and yielded a decrease of almost 80%. This novel platform provides an alternative method for the quantitative determination and remediation of Cr(VI).