TiO2-graphene hybrid nanostructures by atomic layer deposition with enhanced electrochemical performance for Pb(II) and Cd(II) detection

In this work, atomic layer deposition is applied to coat graphene nanosheets with TiO2. The produced TiO2-graphene (TiO2-Gr) composites are characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. It is revealed that TiO2 is effectively deposited on the surface of graphene. The coatings have a highly controlled thickness. The electrochemical properties of the obtained TiO2-Gr composites are investigated for detection of lead (Pb2+) and cadmium (Cd2+) ions by differential pulse anodic stripping voltammetry (DPASV). It is found that the TiO2-Gr composite exhibits improved sensitivity for detection of these metal ions. The linear dynamic ranges are from 1.0 x 10 (8) M to 3.2 x 10 (5) M for Pb2+ and 6.0 x 10 (7) M to 3.2 x 10 (5) M for Cd2+, respectively. The detection limits (S/N = 3) are estimated to be 1.0 x 10(-10) M for Pb2+ and 2.0 x 10(-9) M for Cd2+, respectively.