A sustainable gel-state ionic liquid-based dye-sensitized solar cell with a novel synthesized lansoprazole functionalized graphene oxide

Abstract

Using environmental-friendly ionic liquid-based (IL) composite electrolytes to assemble gel-DSSC can restrict volatile organic solvent electrolyte leakage and improve device flexibility and sustainability. Through a covalent functionalization technique, a new class of 2- {(3-methyl-4-(2, 2, 2-trifluoroethoxy) pyridin-2-yl) methylsulfinyl}-1H-benzo(d)imidazole (lansoprazole, LNS) was covalently grafted onto graphene oxide sheets (GO). The incorporation of GO-LNS nanofillers could enhance the redox couple diffusion and conductivity of IL-based electrolytes due to the increased number of electronic and spatial active sites of mobile defects of GO by electron-rich nitrogen, oxygen, and sulphur heteroatoms. A gel-DSSC device fabricated with optimized GO-LNS/IL showed nearly 93% higher ionic conductivity and almost less than twice charge transfer resistance compared to the device made with standard IL-based electrolyte. The excellent electronic properties of GO-LNS containing electrolytes developed the photoelectrochemical characterization considerably. Thus, the overall performance of the gel-DSSC devices showed the maximum power conversion efficiency of 7.158% instead of 3.127% for the bare IL-based electrolyte. Such excellent efficiency correlating with the induced N, S, O, and F atoms localized at the LNS functional group can change the electronic states of graphitic carbon, which results in active sites for catalyzing I3− to I− decrease. On the other hand, fluorine atoms in the trifluoroethoxy group can provide binding sites for I2 molecules. This covalent modification of GO with lansoprazole assembly may develop effective strategies for practical application through an advanced class of environmentally friendly and sustainably produced IL-based nanocomposites.