Hi there. When you use UV-Vis spectra you just have to look out for the plasmon band (500-550 nm) of gold.

If you observe the plasmon band, then:

a.) Au is the shell and ZnO is the core or you have just simple composites without any core/shell structure.

b.) If you do not see that plasmon band, than most probably your Au is the core an ZnO is the shell.

However, if you want to publish your results you have too examine your sample by HR-TEM and identify your phases/components by the lattice fringes.

I hope this information was helpful.Cheers,

Zsolt

It is difficult to understand the core shell structure from UV-visible spectroscopy. Better to go for XRD, TEM, and HR-TEM.

Thank you very much for all

 Dear Sudip,

Can you explain that how can we confirm it from XRD, TEM, HRTEM, if we have nanohetrostures quantum dots ?