Preparations, Characterizations, and a Comparative Study on Photovoltaic Performance of Two Different Types of Graphene/TiO₂ Nanocomposites Photoelectrodes

Abstract

This research work undertook a comparative study of the promoting effects of graphene in TiO2 photoanodes. The aim of this work was to investigate the effects of the types and concentration of reduced graphene oxides (rGO) on structure properties and the photovoltaic performance of TiO2 based electrodes. Graphene oxide (GO) was prepared by using modified Hammer’s method. Next, GO was reduced by using two different approaches, which were the chemical reduction with vitamin C and thermal reduction. The latter approach was also carried out in situ during the fabrication and heat treatment processes of the dye-sensitized solar cells (DSSCs). From the results, it was found that the photovoltaic performance of the DSSCs containing the GO/TiO2 electrode, in which the GO phase experienced an in situ thermal reduction, was superior to those containing rGO/TiO2. It was also found that the power conversion efficiency of the DSSCs changed with the concentration of graphene in a nonlinear fashion. The optimum concentrations of graphene, corresponding to the highest PCE values of the GO/TiO2 based DSSC (3.69%) and that of the rGO/TiO2 based cell (2.90%), were 0.01 wt% and 0.03 wt%, respectively.

Hydrothermal Synthesis of rGO-TiO2 Composites as High-Performance UV Photocatalysts for Ethylparaben Degradation

“…The crystal size is 20.6 nm for anatase and 19.3 nm for rutile. In composites with P25, the crystal size is changed by the presence of rGO (Table S1) [52]. The TiO 2 sample prepared for this study contains 100% anatase.…”

Synthesis and characterization of hybrid materials based on graphene oxide and silica nanoparticles and their effect on the corrosion protection properties of epoxy resin coatings

“…GO was prepared from natural graphite powder through the modified Hummers method [27]. First, 2.0 g of graphite was mixed with 1.5 g of NaNO 3 and 50 mL of concentrated H 2 SO 4 and stirred for 3 h. Subsequently, the mixture was kept below 5 C using an ice bath, and 6 g of KMnO 4 was gradually added to the above solution while keeping the temperature at less than 20 C. The mixture was then stirred at 35 C for 24 h. Noteworthy is that the reaction between KMnO 4 and the graphite solution is exothermic and thus attempts were made to maintain the temperature below ambient temperature (35 C) [28]. After that, 100 mL of water was slowly added to the above mixture during a period of 30 min.…”

Graphene/Metal Oxide Nanocomposite Usage as Photoanode in Dye-Sensitized and Perovskite Solar Cells

“…The photovoltaic parameters thus calculated are open-circuit voltage (VOC), short circuit current (I SC ), fill factor (FF) and power conversion efficiency. In 2016, the Graphene/Metal Oxide Nanocomposite Usage as Photoanode in Dye-Sensitized and Perovskite… DOI: http://dx.doi.org /10.5772/intechopen.88971 power conversion efficiency values certified by the National Renewable Energy Laboratory (NREL), the best research dye-sensitized solar cell, organic photovoltaic cell (OPV) and the perovskite solar cell, are 11.9, 11.5 and 22.1%, respectively [10].…”

“…Kanta et al [10] carried out comparative study of the promoting effects of graphene in TiO 2 photoanodes. They investigated the effect of the types and concentration of rGO on structural and photovoltaic properties of TiO 2 -based electrodes.…”