Reduced graphene oxide/platinum hybrid counter electrode assisted by custom-made triple-tail surfactant and zinc oxide/titanium dioxide bilayer nanocomposite photoanode for enhancement of DSSCs photovoltaic performance

In this work, custom-made triple-tail sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-silphonate (TC14) surfactant was used to assist exfoliation through electrochemical method for synthesis of graphene oxide (GO). A commercially available single-tail sodium dodecyl sulphate (SDS) surfactant was also utilised for comparison. Both synthesised GOs were reduced to produce reduced GO (rGO), which was fabricated into thin films through spray coating. The rGO thin film assisted by TC14 surfactant (TC14-rGO) with Pt nanoparticles was hybridised to improve electrical conductivity. The five different fabricated thin films were TC14-GO, TC14-rGO, SDS-rGO, Pt and TC14-rGO/Pt hybrid, which were used in dye-sensitised solar cells (DSSCs) as counter electrode (CE). Zinc oxide nanorods/titanium dioxide (ZnO NRs/TiO2 bilayer) was used as photoanode and fabricated through a simple sol–gel immersion and squeegee method. Based on solar simulator measurement, TC14-rGO/Pt hybrid CE thin film exhibited the highest energy conversion efficiency of approximately 0.044% with the Voc, Jsc and FF values of approximately 0.618 V, 0.163 mA/cm2 and 0.387, respectively, compared with other fabricated CE materials. The combination of TC14-rGO/Pt hybrid CE and ZnO NRs/TiO2 bilayer photoanode enhanced the DSSCs photovoltaic performance because of the high conductivity, low oxygen content, high quality and less agglomeration of thin rGO films as a result of improved exfoliation by triple-tail TC14 surfactant.