Carbon dots as solid-state electron mediator for BiVO4/CDs/CdS Z -scheme photocatalyst working under visible light

Z-scheme photocatalytic system is an efficient way to achieve high efficiency photocatalytic overall water splitting. However, the acquisition of efficient Z-scheme visible-light photocatalysts is still a huge challenge at present due to the inactive visible light-active component and various low-band-gap for semiconductors. Herein, we constructed the BiVO4/CDs/CdS Z-scheme photocatalyst with carbon dots (CDs) as solid-state electron mediator, which exhibits excellent photcicatalytic activity and stability for photocatalytic overall water splitting under visible light. The BCC50 (BiVO4/CDs/CdS with the mass ratio of BiVO4/CdS = 50%) as photocatalyst shows the best photocatalytic activity with stoichiometric ratio of H-2 evolution rate of 1.2412 mu mol/h and O-2 evolution rate of about 0.61 mu mol/h. The enhanced photocatalytic activity of the Z-scheme photocatalyst can be attributed to high efficiencies for separation and transport of photogenerated charge carriers and extended the lifetime of electrons and holes. (C) 2017 Elsevier B.V. All rights reserved.