No abstract

The nanocomposite of titanium-di-oxide (TiO 2 )/iodine (I 2 ) in polyvinyl alcohol (PVA) matrix has been explored to be used in hydrogen peroxide (H 2 O 2 ) sensing applications for the first time. The proposed nanocomposite can be easily casted in the form of thin film on glass substrates as well as free standing membranes. These nanocomposite films and membranes exhibit reduced resistance values and easily observable colour changes in the presence of H 2 O 2 . The films also exhibit significant quenching in photoluminescence emission properties upon H 2 O 2 exposure. These sensor responses have been attributed to redox reactions at nanocomposite films and H 2 O 2 interface. This study indicates an easy to fabricate, flexible and environmental friendly sensing platform for H 2 O 2 .

The quest for cost effective and efficient solid-state electrolytes is a primary goal for dye sensitized solar cells (DSSCs). The present study describes an experimental approach of synthesizing simple composite electrolytes from iodide-triiodide ions (I−/I3−) incorporated into a polyaniline/thiourea matrix for solid-state DSSC applications. This electrolyte composition can be effectively used to decrease the probability of recombination at the TiO2/electrolyte interface and increase the catalytic process of I3− reduction at the electrolyte/counter electrode interface. The application of the optimized electrolyte in DSSC results in increased open-circuit voltage as well as short circuit current density, thereby increasing the overall efficiency by 73% as compared to the reference electrolyte. The present composition can prove to be a promising redox medium for solid state DSSCs.

SEM micrograph of the optimized electrolyte with SCN : TU. Inset shows the current density–voltage characteristics of the DSSCs with reference and optimized electrolytes, A1 and A2, respectively.