Ligand removal from CdS quantum dots for enhanced photocatalytic H2 generation in pH neutral water
Ligand-free CdS quantum dots were produced by a reactive ligand stripping procedure and employed for photocatalytic H2 evolution in pH neutral solution. The rate of H2 generation of the ‘bare’ quantum dots was 175 times higher than that of the equivalent mercaptopropionic acid-capped quantum dots in the presence of a cobalt co-catalyst and Na2SO3 as a sacrificial electron donor. Under optimised conditions, a turnover number of 58000 mol H2 per mol Co and 29000 mol H2 per mol CdS quantum dots was achieved after 88 h of UV-free solar light irradiation (λ > 420 nm, 1 Sun intensity). Ligand removal is therefore a potent method to substantially enhance the photocatalytic performance of quantum dot systems.