Plasmon mediated Fe-O in an octahedral site of cuprospinel by Cu NPs for photocatalytic hydrogen evolution.

Cu NPs (copper nanoparticles) were synthesized in situ on the surface of CuFe2 O4 (cuprospinel). The enhancement of the separation efficiency of photogenerated e- /h+ and the catalytic quantum efficiency showed that the LSPR (local surface plasmon resonance) of Cu NPs facilitated the photocatalytic reaction activity of CuFe2 O4 . And due to the fact that CuFe2 O4 was constructed with Cu-O in the tetrahedral site and Fe-O in the octahedral site, the results of DTG and Raman spectra after HER (hydrogen evolution reaction) displayed that the phase change of Fe-O in the octahedral site of CuFe2 O4 took place during the HER process, and along with the peak of Fe2+ in XPS spectra after HER, which indicated that light activated Fe-O in the octahedral site was responsible for the photocatalytic process.