A solution-processed, mercaptoacetic acid-engineered CdSe quantum dot photocathode for efficient hydrogen production under visible light irradiation

We describe here a simple, efficient and stable CdSe QDs/NiO photocathode engineered using a molecular linker, mercaptoacetic acid (MAA), for H-2 generation from neutral water. This protocol does not require any sacrificial reagent, external cocatalyst, protecting layer and buffer solution as well. Upon visible-light irradiation, photocurrent as high as -60 mu A cm(-2) is achieved at a bias of -0.1 V vs. NHE in 0.1 M Na2SO4 (pH 6.8). Simultaneously, the photocathode evolves H-2 consistently for 45 h with similar to 100% Faradic efficiency, which is unprecedented in the field of sensitized photocathodes for H-2 production. A mechanistic study reveals that the exceptional performance is derived from the efficient hole transfer process.