“…For example, for Ce III PO 4 (rhabdophane), the value of E g calculated by Lima et al was 2.7-2.8 eV, 56 for Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5 it was 2.7 eV 64 and for amorphous cerium pyrophosphate it was 2.3 eV. 61 The values of the energy band gap obtained in the current study are consistent with the literature data and indicate the 54 2.7 2.5 0.9 3.2 TiO 2 (rutile) 54 3.1 3.1 1.0 3.0 possibility of using cerium(IV) phosphates as components of UV protective materials: Cole et al, 75 using the example of zinc and titanium oxides (inorganic sunscreens approved by the FDA, E g = 3.1-3.3 eV 76 ), showed that metal oxide sunscreens protect skin by light absorption, not by reflection or scattering, with absorption efficiency being associated with the semiconductor band gap. At wavelengths above the semiconductor band gap absorption energy levels (in the long-wavelength UV-A and visible range), semiconductor nanoparticles predominantly reflect (up to 60% reflection), and do not absorb, radiation.…”