Exploring the potential of potato starch-capped TiO2 nanoparticles for DSSC photoanodes

Abstract

Capping agents are widely employed to stabilize the synthesized nanoparticles. To address the problems associated with the chemical capping agents and agglomeration of nanoparticles in the chemical and physical methods, green synthesis methods based upon the usage of biodegradable, well-dispersed capping agents have widely been used. In this work, TiO2 was synthesized by simple sol–gel method and a green capping agent, potato starch has been used. Potato starch consist of two basic biopolymers i.e. amylose (∼20 %) and amylopectin (∼80 %), that binds through the functional groups viz. hydroxyl, carboxylic or amino groups with the metal cations to prevent agglomeration of the growing NPs. The structure and morphology of the synthesized TiO2 were characterized by FTIR and XRD, where the XRD patterns confirmed the anatase phase of TiO2. From the Tauc’s plot, the band-gap of un-capped and differently capped TiO2 was obtained. Potato starch-capped TiO2 coated with the Ru dye (N719) revealed photoelectric conversion efficiency of 2.58 % under illumination of 100 mW/cm2, that was much upgraded compared to the performance with the un-capped TiO2 (1.84 %). The EIS studies revealed the kinetic parameters. The illustrated results showed that potato starch-capped TiO2 have greater potential in enhancing the DSSC efficiency.

Keywords

• DSSC
• Capping
• TiO2
• Starch
• Semiconductor
• Thin film