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

Abstract

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.