Enhancement in the photocatalytic H₂ production activity of CdS NRs by Ag₂S and NiS dual cocatalysts

Cocatalysts play an indispensable role in photocatalytic H₂ production via water splitting for the conversion of solar energy into storable chemical energy. Herein, the hybrid catalyst CdS/Ag₂S/NiS is synthesized via hydrothermal and photodeposition methods. CdS/Ag₂S/NiS shows a drastically elevated hydrogen production rate of 48.3 mmol g⁻¹ h⁻¹ under visible light due to the combined merits of the Schottky junction between CdS and metal-like Ag₂S and the constructed p–n junction between CdS and NiS. Time-resolved photoluminescence spectroscopy and photochemical tests reveal the accelerated charge transfer and significantly reduced electron–hole pair recombination. Further investigation with in-situ surface photovoltage imaging technology demonstrates that the reduction cocatalyst Ag₂S and oxidation cocatalyst NiS can serve as photogenerated electron and hole traps, respectively. This research not only provides insight into designing high-efficiency photocatalyst for hydrogen production but also utilize a brand new method for the confirmation of charge–carrier migration pathways. Copyright © 2021 Elsevier B.V. All rights reserved.