Metal sulfide photoanodes emerge into an efficient platform for converting light energy into hydrogen by water splitting. Herein, we demonstrate the facile fabrication of a ternary photoanode (TiO2/Ag2Se/CdS) by decorating a TiO2/Ag2Se electrode with CdS quantum dots. The ternary electrode exhibits low charge transfer resistance, and high-density photocurrent (24.6 mAcm−2 at 1.23 V). We estimate the photon-to-hydrogen conversion efficiency at 14% (at 0.43 V) due to sulfite oxidation. Also, Ag2Se improves the electrode stability, highlighting the promising nature of the electrode for practical applications. These excellent photocatalytic properties of TiO2/Ag2Se/CdS are achieved by the favorable band-edges positions of CdS and Ag2Se quantum dots, the broad absorption of solar photons in the UV-to-NIR region, and the separation and transport of charge carriers. © 2021 Hydrogen Energy Publications LLC