CoPtx-loaded Zn0.5Cd0.5S nanocomposites for enhanced visible light photocatalytic H2production

Zn0.5Cd0.5S solid solution, modified with bimetallic CoPtx nanoparticles, has been prepared using a two-step organic solution method. The photocatalytic H2 production rate of CoPtx–Zn0.5Cd0.5S nanocomposites with different composition and percentage of CoPtx was investigated. The results showed that the 1 wt% CoPt3–Zn0.5Cd0.5S sample had the best activity which was 4.7 times higher than that of pure Zn0.5Cd0.5S and 1.2 times higher than that of Pt–Zn0.5Cd0.5S for photocatalytic H2 production. The transient photocurrent response of the Zn0.5Cd0.5S showed an obvious increase in the current density after CoPtx loading. Electrochemical impedance spectra measurements showed that the CoPtx–Zn0.5Cd0.5S nanocomposites with x = 2 and 3 had lower charge transfer resistance Rt than that of Pt–Zn0.5Cd0.5S. The enhanced catalytic properties of the CoPtx–Zn0.5Cd0.5S nanocomposites are attributed to their better accumulation ability for photoexcited electrons and higher rate for charge separation and transportation. Copyright © 2016 John Wiley & Sons, Ltd.