Nanocomposites based on 3D honeycomb-like carbon nitride with Cd0.5Zn0.5S quantum dots for efficient photocatalytic hydrogen evolution

Honeycomb-like graphitic carbon nitride (H-C3N4) with unique morphology has been studied as a promising polymer photocatalyst. Herein, a novel binary metal sulfide constructed with H-C3N4 (Cd0.5Zn0.5S/H-C3N4) was prepared though the facile in situ precipitation method. The characterization data suggest that Cd0.5Zn0.5S quantum dots (QDs) are well dispersed on the macroporous structure of H-C3N4 (156 m(2) g(-1)), which can provide higher surface area, more catalytic active sites and larger interface contact area with accelerating the migration and separation of charge carriers. By taking advantage of 0D/3D heterojunction structure, the Cd0.5Zn0.5S/H-C3N4 dramatically boosts the photocatalytic H-2 evolution rate with the visible-light illumination. The Cd0.5Zn0.5S/H-C3N4-3 yields the highest photocatalytic activity of 5145 mu mol h(-1) g(-1), which is 4.3 times as high as that of pure Cd0.5Zn0.5S. Furthermore, Cd0.5Zn0.5S/H-C3N4 composite presents high stability after four recycles. The enhanced visible-light-driven photocatalytic H-2 production is attributed to the construction of n-n type heterojunction as well as the large surface area, which can inhibit the agglomeration of Cd0.5Zn0.5S nanoparticles, and efficiently transfer the photo excited electron-hole pairs in Cd0.5Zn0.5S. Therefore, this work provides a potential way for designing advanced 0D/3D heterojunction. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.