Cobalt Catalyst Grafted CdSeTe Quantum Dots on Porous NiO as Photocathode for H₂ Evolution under Visible Light

A photoelectrochemical cell for water splitting was first reported using CdSeTe quantum dots (QDs) as its superior photoelectric efficiency and photostability under the irradiation of visible light. Using the mesoporous p-type NiO as hole conductor and a cobaloxime catalyst as the economic cocatalyst for the hydrogen evolution reaction without sacrificial electron donor, the Co-CdSeTe-NiO photocathode exhibited a considerably high photocatalytic current density of-130 μA cm^-2 at a bias of-0.1 V vs NHE in a near neutral electrolyte upon illumination. Simultaneously, the photocathode produced 2.9 μmol H₂ with almost 93% Faradaic efficiency over 3 h illumination at-0.3 V vs NHE. It suggested that CdSeTe QDs could be used as good light absorber, and the Co-CdSeTe-NiO photocathode exhibited efficient photocatalytic ability.