Polypyrrole-based chalcogen/chalcogenide nano-composites and their energy applications: A review

Abstract

Substantial research and development in the field of conducting polymers and their composites has opened up new avenues in the field of energy applications. Conducting polymers exhibited various properties that can be tuned according to necessity, which has led to extensive research on them, including hybridizing them with nano-particles to eliminate their limitations. The hybrid nano-composites exhibited great potential when conducting polymers were combined with either transition metals, their oxides, metal chalcogenides and/or chalcogens. Consequently, amongst the conducting polymers, polypyrrole (PPy) has gained high popularity in regards to its attributes. Researchers have developed number of methods for synthesizing PPy and their nano-composites with chalcogens/chalcogenides over the past two decades for different fields of application. Chalcogens/chalcogenides such as sulfur (S), selenium (Se) and tellurium (Te) using a variety of their precursors and various in-situ/ex-situ polymerization techniques for potential nano-composites have been designed and documented in the literature. The nano-composites have technological importance owing to their tunable properties, such as electrical conductivity, thermal conductivity, mechanical strength, structural enhancement and optical behaviour etc. Presence of chalcogen significantly improve opto-electronic properties of PPy and its nano-composites to make them versatile materials for a range of electronic applications. In current scenario, the necessity for creative energy solutions is required for global energy crisis. Waste energy recycling can convert waste heat into power in an economical and environmentally beneficial manner by using polymer-nano-composites based thermoelectric (TE) technologies. This review provides an overview on synthesis of PPy/chalcogen or chalcogenides composites and their characterizations e.g. X-ray diffractions (XRD), UV-Visible, infrared and Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) for analysis of their salient properties desired for a variety of applications e.g. gas sensing, photovoltaics, supercapacitors, and thermoelectric generators etc.