In the case of CuO-Al2O3, Al2O3 is highly hydrophilic in nature in comparison of CuO, So with the increased contents of CuO in CuO-Al2O3 nanocomposite, it is getting hard to dissolve the material in water to get good UV-Vis spectra. Consequently, when I filter my material to get clear solution for UV-Vis spectra, then I found only dominant absorbance behavior of Al2O3 in nanocomposite, which is logically not acceptable.
So how can I resolve this issue by selecting just water or ethanol as solvent. ???