Multiple exciton generation application of PbS quantum dots in ZnO@PbS/graphene oxide for enhanced photocatalytic activity

Multiple exciton generation (MEG), also known as carrier multiplication (CM), is a process in which absorption of a single photon produces more than one electron-hole pairs. We introduce PbS QDs with multiple exciton generation (MEG) property into the construction of a novel ZnO@PbS/GO structure photocatalyst and applied to suspended photocatalytic H-2 evolution from water for the first time. The presence of multiple exciton generation process in PbS QDs, which is confirmed by transient absorption spectrum and photocurrent measurements, remarkably improves the photocatalytic efficiency of hydrogen generation combined with the electron-hole separation of GO. This strategy is proposed to open a new way for the photocatalysts design to achieve high efficiency based on QDs materials with MEG property. (C) 2014 Elsevier B.V. All rights reserved.