Synergistically-mediated highly-efficient visible-light-driven hydrogen evolution activity using Ohmic/Schottky-type dual-junctions and sulfur vacancy.

ABSTRACT

Enabling highly-efficient multiplex-optimization photocatalysts is critical to overcome the bottlenecks of hydrogen evolution reaction efficiency and photostability. Herein, novel CoS/Sv-ZnIn2S4/MoS2 composites are successfully synthesized through an in situ technique. Taking advantage of the synergistic effect of sulfur vacancy, Schottky-type MoS2/Sv-ZnIn2S4 junction and Ohmic-type CoS/Sv-ZnIn2S4 junction, the light absorption, electron/hole separation efficiency, charge transfer rate and hydrogen reduction reaction dynamic can be significantly enhanced. As a result, an impressive photocatalytic hydrogen evolution rate of 18.43 mmol g-1 h-1 is achieved under the visible-light irradiation. Furthermore, apparent quantum efficiencies of 72.14 % and 9.91 % are also achieved under 350 and 420 nm monochromatic light irradiation. This work presents an in situ perspective to design multiplex-optimization photocatalytic system for highly-efficient hydrogen production.