Hello,

You can calculate a band gap then find the range of wavelength to know the range of his work.

you application it with certain color organic compound (dye) under light source of UV-A or by using Solar light to ensure from your work.

Actually size of the ZnO nanoparticles plays an important role. Normally absorbtion peak found at 258nm but it varies from 210-410 nm depends on the size and band gap wavelength of the nanoparticles.

ZnO nanoparticles UV spectrum range is

200nm------1100nm