Synthesis of Titanium Dioxide (TiO2)/Reduced Graphene Oxide (rGO) thin film composite by spray pyrolysis technique and its physical properties

TiO2/reduced graphene oxide (rGO) thin films prepared from different GO concentrations (0, 3, 5, and 10 wt%) were successfully deposited on fluorine-doped tin oxide (FTO) glass substrates using spray pyrolysis technique (SPT). The structural, morphological and optical properties of the thin films were examined using Raman spectroscopy and X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV-Vis spectroscopy, respectively. The presence of rGO in the thin films structure was confirmed by Raman analysis with D and G band intensity ratios (ID/IG) of 1.01, 1.03 and 1.08 for GO concentrations of 3, 5, and 10 wt%, respectively. The characteristic XRD peaks for TiO2 and rGO at 2 circle minus values of 25.3 degrees and 22-23 degrees, respectively, indicate the bonding of TiO2 with rGO. Surface morphology analysis of the TiO2/rGO thin films reveal homogenous distribution of graphene nanosheets and TiO2 on FTO glass substrate. In addition, optical transmittance reduced from 80% for TiO2 to 45% for TiO2/rGO prepared with 10 wt% GO. From UV-Vis analysis, band gap energy for TiO2 , and TiO2 /rGO reduced from 3.63 eV to 3.38 eV, with increase in the concentration (wt.%) of GO in the thin films. Thus, the use of the SPT method is believed to provide a cost-effective and easy approach to synthesize good quality TiO2/rGO thin film on FTO glass for photodetector and solar cell applications.