Since Yang et al. employed [Ru(bpy)3](PF6)2 as the PC, an excitation at 468 nm was used throughout their study. By contrast, the higher energy absorption onset of the Cu(I) complexes studied by Minozzi et al. meant that excitation at 394 nm was more suitable for most of their A significantly different yield was obtained in our set-up compared to that of Minozzi et al.