3D spatially branched hierarchical Z-scheme CdS-Au nanoclusters-ZnO hybrids with boosted photocatalytic hydrogen evolution

Integrating multi-dimension functional materials into an oriented nanoarchitecture is promising to construct an efficient all-solid-state vectorial Z-scheme artificial photosynthetic system with dimensionality-dependent merits. Herein, a Z-scheme photocatalyst with three dimensional (3D) spatially branched hierarchical heterostructure has been constructed for photocatalytic hydrogen production by growing ZnO arrays via a seeded growing methodology on the surface of CdS nanowires which is modified with zero dimensional (OD) Au nanoclusters (Au-x). Two strategies have been employed to significantly enhance H-2 evolution. The first is demonstrated through compositing Au-x on CdS nanowires to promote the efficient separation of electrons and holes. The second is a branch-growth method to achieve high branching of CdS nanowires. The photocurrent density is observably increased for the new composited photoanode. Due to a synergetic interaction of energy band matching at the interfaces of 3D multicomponent materials, the resultant Z-scheme photocatalyst achieves boosted and robust photocatalytic activity for the generation of H-2. The as-prepared amount-optimized composite exhibits a H-2 evolution rate of 102.9 mu mol h(-1 )with an apparent quantum yield (A.Q.Y.) of 9.6% when irradiated at 420 nm, which is remarkably higher than those of its counterparts. The performance enhancement is attributed to the synergy between the reduced recombination of photo-generated electrons and holes by compositing Au-x and the greatly increased absorption of light associated with the ZnO nanowire branching. (C) 2018 Elsevier B.V. All rights reserved.