Effect of tin oxide crystallite size on the efficacy of polyaniline-tin oxide nanocomposite based counter electrode for DSSC applications

The underlying objective of the work was to establish a PANI-SnO2 nanocomposite based counter electrode as an alternative to the conventionally used Pt counter electrode, in designing cost-effective and transparent DSSCs. The effect of SnO2 crystallite size on the efficacy of the synthesized counter electrode for DSSCs was studied. Owing to high catalytic activity, transparency in the visible region and cost effectiveness, PANI has been found to be novel material for synthesizing counter electrodes. In order to increase conductivity and catalytic activity of PANI further, a low cost SnO2 dopant was utilized as instead of traditional dopants like TiO2, SiO2, Fe3O4, MnO2 etc. SnO2 was prepared by means of a co-precipitation reaction involving tin chloride dihydrate and oxalic acid dihydrate. By variation of sintering temperature, differently sized SnO2 nanoparticles were obtained. A facile in-situ polymerization method was used to synthesize the nanocomposite of SnO2 − PANI. To ascertain the crystallinity, morphology and catalytic behavior of the nanocomposite XRD, SEM and EDS studies were done. Thermal properties and functional groups were investigated using FTIR and Thermogravimetric studies. Further analysis was done using optical spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy.