Graphene oxide (GO) layer has been successfully deposited on to ITO/TiO2 substrate by electrochemical deposition. Deposition process of GO layers were carried out in one, three, and six cycles in the voltage range of-1.6 to 0 volt and scan rate of 50 mV/s. The variation of cycles was performed, in order to study the deposition process relates to device performances. TiO2 macro-channel (TiO2μc) also introduced in photoanode system and it required annealing treatment up to 500°C. The oxygen content in GO will be reduced by annealing treatment and the reduced-GO (rGO) layer was trapped inside of TiO2 mesoporous. The cyclic voltammetry curves of blank sample and GO deposition were also observed in order to ensure the GO deposition process was successfully done. After immersing in ruthenium dye overnight, the ITO/TiO2/rGO/TiO2-μc was sandwiched with Pt/FTO as counter electrode to configure dye sensitized solar cell (DSSC) structure. The photovoltaic characteristics, morphology, and UV-Vis absorbance of each layer were investigated. A highest DSSC efficiency (η= 3.34 %) was achieved by 3-cycles of GO deposition process of photoanode with photocurrent density (Jsc) of 9.94 mA/cm2, open voltage (Voc) of 0.70 V and fill factor (FF) of 48.69% under 100 mW/cm2 of light irradiation.
Photoreduction of CO2 over Ruthenium dye-sensitized TiO2-based catalysts under concentrated natural sunlight