Metal Sulfide Nanocomposites for Energy Harvesting Applications

The global challenges relating to energy harvesting could be solved using nanotechnology, which provides progressively elaborated and ingenious geometric structures, which can incorporate an accrescent material surface. For this purpose of energy harvesting, metal sulfides are serving as an emerging generation. For the conversion of electrochemical energy, metal sulfides have gained considerable attention as favorable electrode material due to their remarkable electrochemical performance including broad potential windows and elevated theoretical capacities. The production of electricity from the waste heat by thermoelectric material is of great interest because of its reliability and simplicity, which enhances energy efficiency. There are some scientific and civil problems regarding the achievement of power densities and high energy for electrochemical conversion. The possible solution to increasing energy demand around the world, for today and to the next generation, is the production of electrical energy directly from light. In this chapter, we have discussed the process by which metal sulfide nanocomposites can be used for energy harvesting, their utilization for eco-friendly and renewable energy demands, and its efficient storage from alternate sources. This chapter also includes different types of nanocomposites of metal sulfides, their synthetic route including one-step electrode coating method, atomic layer deposition method, one-step high-temperature solvothermal synthesis, hydrothermal method, metal sulfide deposition method, wet chemical method, low-temperature water bath technique and modified hummers method followed by hydrothermal method, hard templating method, soft templating method, and sacrificial templating method, and one step hydrothermal and sol-gel synthesis method. For the elucidation of their structural and morphological characteristics and functional properties, different techniques including SEM, TEM, X-ray photoelectron spectroscopy (XPS), UV/Vis absorption spectroscopy, XRD, cyclic voltammetry (CV), FTIR, BET (surface and pore size studies) and TGA have been discussed. Analysis for application potential of metal sulfides is elaborated based on several modes of their applications including photo/electrochemical energy storage and conversion, semiconductor solar cells, photocatalytic hydrogen production, electrochemical capacitors, hybrid solar cells with enhanced photocurrent, and solar energy harvesting. Some of the future concerns are also discussed related to their feasibility, production of composites containing multifunctional hybrids, stability and life span of composite, solution or medium for their regeneration, and their safe dumping.