Selective hydrogen–deuterium exchange in graphitic carbon nitrides: probing the active sites for photocatalytic water splitting by solid-state NMR

By selective deuteration, the exchangeable and unexchangeable protons of the H-containing groups of g-C₃N₄ were differentiated, providing a way to distinguish the hydrophilic and relatively non-hydrophilic H-containing groups of g-C₃N₄.