Facile synthesis of TiO2-ZnO-rGO nanocomposites for highly sensitive simultaneous determination of hydroquinone and catechol

In this paper, a glassy carbon electrode (GCE) modified with TiO2-ZnO-reduced graphene oxide (TiO2-ZnO-rGO) nanocomposites was designed for the selective and simultaneous quantification of hydroquinone (HQ) and catechol (CA). The TiO2-ZnO-rGO nanocomposites were prepared by a simple ultraviolet irradiation method for the first time. In the process of ultraviolet radiation, the photogenerated electrons in TiO2 and ZnO were transfered into GO which was then reduced to form rGO. Benefiting from functional properties of different components and synergistic effect, the TiO2-ZnO-rGO nanocomposites exhibited excellent sensing performance for the selective and simultaneous determination of HQ and CA. Under the optimized conditions, the linear ranges for selective assay of HQ or CA in the existence of 40 mu M of the respective isomer are 5-500 mu M. The linear ranges for simultaneous assay of HQ and CA are obtained from 0.1 to 100 mu M with the detection limits of 0.03 mu M (HQ) and 0.05 mu M (CA), respectively. The TiO2-ZnO-rGO/GCE also displayed excellent stability and satisfactory recovery when applied for real water samples analysis.