The synthesis, properties, and potential applications of CoS2 as a transition metal dichalcogenide (TMD)

Cobalt disulfide (CoS2) is an attractive member of the dichalcogenides family, which has attracted a lot of attention due to its abundance of constituents and its special properties such as semi-metallic conductivity and large surface area. Particularly, the high theoretical capacity of CoS2 is so beneficial for energy storage systems such as different types of batteries, supercapacitors, and dye-sensitized solar cells (DSSCs). Furthermore, CoS2 has the lowest chemisorption energy for atomic hydrogen among other pyrite types. In this review, different methods for the synthesis of CoS2 are discussed and the role of CoS2 as an active electrode material for various applications such as different kinds of batteries, supercapacitors, DSSCs, an electrocatalyst for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR) reactions, and as a component in the sensor's construction is investigated. Moreover, several solutions to solve the challenges of using CoS2, such as volume changes during cycling or aggregation of nanoparticles, are presented and discussed. We hope that this information will be beneficial for many researchers around the world and suggest promising paths for future projects.