Homogeneous Photocatalytic Hydrogen Evolution System with Assembly of CdSe Quantum Dots and Graphene Oxide

Abstract

Hydrogen is a promising energy carrier to replace traditional fossil fuel and could be obtained by the artificial photosynthesis. Herein, a homogenous system combined CdSe quantum dots (QDs) and graphene oxide (GO) (GO/CdSe QDs) were prepared by simple ultrasonication and stirring method for highly efficient photocatalytic hydrogen evolution. Notably, the optimized photocatalytic H2 evolution rate reached as high as 33.88 mmol g−1 h−1 for GO/CdSe QDs, which is about 7.9 times than that of pure CdSe QDs. The X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) confirmed that the GO has been successfully coupled with CdSe QDs and has ignorable influence on the original crystal structure and morphology of CdSe QDs. Importantly, we found that the hydrophilicity of GO is necessary to ensure its intact interaction with CdSe QDs for the continuous H2 production. The significant activity enhancement mainly attributed to the acceleration of charge migration and dynamics of proton reduction after introducing GO, which has been proved by electrochemical measurements, photoluminescence spectroscopy (PL) and dynamic decay of samples.