“…99 EPR can detect OVs, both at the surface and in the bulk medium in a wide range of substrates, e.g. titanium-based catalysts (TiO 2 , SrTiO 3 ), 12,68,75,83,100,101 bismuth-based catalysts (Bi 24 O 31 Br 10 , BiOCl, Bi 2 O 3 , BiVO 4 , BiO x , Bi 5 O 7 Br), 102–105 tungsten-based catalysts (WO 3 , W 18 O 49 ), 106 SnO 2 , 107,108 CuCr-LDH, 109 CuO, 110 Fe 2 O 3 , 111 Cu 2 O@CuNiMo 112 and CuZnAl-LDH. 79 OVs usually give rise to an isotropic, single-line EPR signal centered at around g ≈ 2.0.…”