A facile one-pot route for the controllable growth of small sized and well-dispersed ZnO particles on GO-derived graphene

In this study, we reported the growth of well dispersed ZnO nanoparticles with small size of about 10 nm on GO-derived graphene via a facile solvothermal method, in which the Zn-EG-Ac complex, graphitic oxide (GO) and ethanol were selected as the Zn precursor, graphene precursor and solvent respectively. The Zn-EG-Ac with plenty of functional groups can interact with the functional groups (COOH, OH) on GO, and thus transform in situ on GO into well-dispersed ZnO without the need of additional alkali. Besides, as solvent, the ethanol also plays the role of a reducing agent that could reduce GO to GO-derived graphene under solvothermal conditions, excluding the use of additional reducing agents. The results indicated that the Zn-EG-Ac precursor was crucial for the formation of the small-sized and well-dispersed ZnO on graphene. Replacing the Zn-EG-Ac complex with Zn(Ac)(2), free ZnO with large size (up to mm) could be observed. In addition, other parameters, such as the amount of the reagent and the kind of solvent, also played an important role in determining the microstructure of the final composites. It needs to be mentioned that we have found the existence of a strong interaction between ZnO and the graphene substrate based on the results of XPS measurements. The interaction was important for improving the performance of the composite; typically, the photocatalytic performance as shown by the photocatalytic degradation of organic pollutants. Overall, our work provides a new avenue for fabricating a ZnO/graphene composite in terms of its simplicity, small size and the good dispersion of ZnO on the graphene, as well as its good performance for photocatalysis applications.