However, the light to hydrogen
conversion efficiency of these systems is reported to be lower than
40%. The low conversion efficiency is mainly due to losses occurring
at the different interfacial charge-transfer reactions taking place in the
multicomponent system during illumination. In this work we have
analyzed all the involved reactions in the hydrogen evolution catalysis
of a model system composed of CdTe quantum dots, a molecular cobalt catalyst and vitamin C as sacrificial electron donor. The
results demonstrate that the electron transfer from the quantum dots to the catalyst occurs fast enough and efficiently
(nanosecond time scale), while the back electron transfer and catalysis are much slower (millisecond and microsecond time
scales). Further improvements of the photodriven proton reduction should focus on the catalytic rate enhancement, which
should be at least in the hundreds of nanoseconds time scale.