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

Abstract

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.