Self-templating synthesis of nitrogen doped graphene quantum dots/3D bismuth oxyiodine hybrid hollow microspheres with improved visible-light excited photocurrent generation: Simultaneous electron transfer acceleration and bandgap narrowing

Abstract

This work presents a self-templating synthetic approach for the synthesis of nitrogen doped graphene quantum dots/3D bismuth oxyiodine (NGQDs/3DBiOI) hybrid hollow microspheres (HHMs) by a facile one-pot solvothermal reaction. In this protocol, the formation of NGQDs/3DBiOI hollow microstructure and the hybridization of NGQDs with BiOI semiconductor were achieved simultaneously in one-pot reaction using the NGQDs as template and dopant, which played a double-acting role in the reaction: (i) to modulate the morphology of BiOI microspheres with special hollow structure; (ii) to hybrid with BiOI for the formation of NGQDs/3DBiOI HHMs. Further investigations revealed that the resulted NGQDs/3DBiOI HHMs exhibit tunable visible-light driven photocurrent generation with varying the amount of NGQDs used in the reaction process, which was ascribed to the simultaneous electron transfer acceleration and bandgap narrowing of the NGQDs/3DBiOI HHMs. Moreover, when evaluated as a matrix for enzyme encapsulation, the resulting NGQDs/3DBiOI HHMs exhibited enhanced load capacity than pure BiOI microspheres by virtue of their particular nanostructure. The design of such three-dimensional NGQDs/3DBiOI HHMs with preferable performance facilitates further multifarious applications for enhanced photocatalysis, enzyme immobilization and biofuels.