Photoinduced Charge Separation in ZnO Quantum Dots and Carbon Nanomaterial Composites

Abstract

We report the successful conjugation of carbon nanomaterials on the surface of ZnO quantum dots (QDs) and vice versa. The synthesis of ZnO QDs and carbon nanomaterial composites was achieved using a mild solution-process method, which resulted in fast photoinduced charge separation. The conjugation of the ZnO QDs to the multi-walled carbon nanotubes (MWCNTs), the graphene to the ZnO QDs and the fullerene (C-60) to the ZnO QDs led to PL quenching of about 80%, 65% and 98%, respectively, which can be attributed to the efficient transfer of photoinduced electrons from the ZnO QDs to the MWCNT, from the ZnO QDs to the C-60 or from the ZnO QDs to the graphene through Zn-O-C chemical bonding.