Since India is one of the most populated countries in the world, there is a constant increase in the demand for food supply. To cater to the increased demand, the farmers use agrochemicals for crop protection and to enhance crop yield. Prolonged use of these agrochemicals, contaminates the groundwater, soil, and air, causing damage to our ecosystem and having adverse effects on human health. The present study reports the one‐pot synthesis of graphene‐CdS (GC) nanocomposites by a facile thermal decomposition approach. Thermal decomposition is an easy and cost‐effective technique. It's a facile and more efficient method than other methods. The synthesized graphene‐CdS nanocomposites were characterized using XRD, FT‐IR spectroscopy, Diffuse Reflectance Spectroscopy, RAMAN spectroscopy, and FE‐SEM analysis. The potential of GC nanocomposites has been explored as an efficient photocatalyst for the degradation of chlorpyrifos (CPY) in an aqueous solution. It was observed that the nanocomposites exhibit 89 % degradation efficiency in 90 minutes compared to the pristine CdS and Graphene. A detailed investigation of the degradation pathway and scavenger studies were also conducted. The Graphene‐CdS hold scope and potential to be explored as an effective photocatalyst for the mineralization of agrochemicals. [ABSTRACT FROM AUTHOR]