Enhanced electrochemical properties of ZnO nanoparticles-incorporated chitosan-based electrolyte as candidates for redox mediator in dye sensitized solar cells

Abstract This study investigates the application of quasi-solid-state polymer electrolytes as a candidate to replace liquid electrolytes in dye-sensitized solar cells (DSSCs) for addressing challenges such as electrolyte leakage and counter electrode corrosion. Chitosan, a biodegradable, non-toxic, odorless polymer known for its high mechanical strength, is explored for its potential in this role. To improve the electrochemical performance of chitosan-based polymer gel electrolytes, ZnO nanofillers, specifically ZnO nanorods and ZnO nanospindles synthesized via hydrothermal methods, were incorporated into the chitosan matrix, which was mixed with KI and I 2 in CH 3 COOH. The polymer gel electrolyte was then characterized using cyclic voltammetry, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The integration of ZnO nanoparticles enhances ionic conduction by providing additional pathways. The results show that incorporating 0.25 wt% ZnO nanorods into the polymer matrix yields anodic and cathodic peak currents of 6.68 mA and −9.37 mA, with a half-wave potential of 0.383 V (vs. Ag/AgCl). In comparison, incorporating 0.5 wt% ZnO nanospindles produces anodic and cathodic peak currents of 7.72 mA and −10.3 mA, with a half-wave potential of 0.380 V (vs. Ag/AgCl).