development of an electrochemical sensor for environmental pollutant detection based on cobalt sulfide and graphene nanocomposite

Hydrazine is a toxic and carcinogenic substance that can enter the human body through multiple pathways, leading to poisoning and other adverse health effects. given its ecological significance in various aqueous environments and its widespread industrial applications, accurate quantification and monitoring of hydrazine in environmental systems are crucial. electroanalytical techniques for hydrazine assessment demonstrate considerable promise owing to their cost-effectiveness, exceptional detection limits, and rapid analytical response. in this study, a new, simple, and cost-effective electrode is proposed and presented for the measurement of hydrazine. this electrode is a modified electrode based on a nanocomposite composed of cobalt sulfide and graphene nanoparticles. the modified cobalt sulfide-graphene electrode, after preparation, was used as a nanocomposite sensor for the electrocatalytic measurement of hydrazine through cyclic voltammetry. due to the presence of nanoparticles in its structure, this electrode exhibits sensitivity and selectivity in the electroanalysis of hydrazine. the effects of various parameters, such as scan rate (from 10 to 300 mv/s), ph (from 3 to 10), and different concentrations of hydrazine (from 0.2 to 2 mm), were investigated. the nanocomposite was characterized using field emission scanning electron microscopy (fesem). to determine the diffusion coefficient of hydrazine, chronoamperometry techniques were used, and the diffusion coefficient of hydrazine in this study was calculated to be 8.48×10-9 cm²/s. the detection limit was determined using differential pulse voltammetry, calculated to be 0.081 mm.