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 H2 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 μA 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 H2 consistently for 45 h with ∼100% Faradic efficiency, which is unprecedented in the field of sensitized photocathodes for H2 production. A mechanistic study reveals that the exceptional performance is derived from the efficient hole transfer process.