▎ 摘　　要

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, 2trifluoroethoxy) 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 I-3(-) to I- decrease. On the other hand, fluorine atoms in the trifluoroethoxy group can provide binding sites for I-2 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. (C) 2022 Elsevier B.V. All rights reserved.