Synthesis and superior SERS performance of porous octahedron Cu2O with oxygen vacancy derived from MOFs

Fabricate surface-enhanced Raman scattering (SERS) substrate with low cost and high performance through simple method is a challenge and worthy of work. Herein, an excellent Cu 2 O SERS substrate with porous octahedron structure was synthesized by brief calcining Cu-MOFs in Ar, air and H 2 /Ar gas environment at 350 °C successively. The as-obtained octahedral Cu 2 O was utilized as SERS substrate to measure dye molecules and organic pollutants, which exhibited splendid sensitivity for the detection of methylene blue and 4-mercaptopyridine (4-MPY) with the ultralow limit of 5 × 10 –9 M and 5 × 10 –10 M, respectively. The maximum relative standard deviation for detection of 4-MPY is as low as 12.3%, which is less than limiting step in quantitative SERS (15.0%). The above excellent results are due to outstanding synergistic effect of electromagnetic enhancement of oxygen vacancy on the Cu 2 O surface and chemical enhancement of the Cu–S bonds formation. The fabricated Cu 2 O possesses superior sensitivity, selectivity and reproducibility for SERS detection of probe molecules with sulfhydryl groups and may be a prospect candidate in the practical application. Graphical Abstract An excellent Cu 2 O SERS substrate with porous octahedron structure was synthesized by simple calcining Cu-MOFs in Ar, air and H 2 /Ar gas environment at 350 °C successively. The as-prepared Cu 2 O play significant roles in the enhancement of SERS signals for rich-thiol detection due to outstanding synergistic effect of electromagnetic enhancement of oxygen vacancy on the Cu 2 O surface and chemical enhancement of the Cu-S bonds formation. The detection limit of 4-Mercaptopyridine (4-MPY) can be as low as 5×10 –10 M. The porous octahedral Cu 2 O will have potential applications in SERS detection as the substrate.