**Abstract**

Demand for environmental protection is gaining more public attention and legislative support. The development in industrial and technological sectors results in severe environmental issues, such as environmental contamination and energy shortage. Therefore, the development of new nanocomposites that can effectively act toward environmental remediation is necessary to overcome the detrimental environmental impacts. Transition metal chalcogenides (TMC) have gained worldwide attention in recent decades and are being researched for use in different applications due to their indirect bandgaps, optoelectronic behavior, and their stability that can enable the catalysts to absorb visible light that is abundant in solar radiation. In this chapter, synthesis, characterization, and application of TMCs, such as MSx and MSex, toward environmental remediation application are reviewed. Efficiency of different TMC materials and different experimental conditions is also elaborated.

**Keywords:** transition metal chalcogenides, degradation, hydrothermal, organic compounds
