Synthesis of green nanocomposite based electrochemical sensor for the detection of water pollutant

Abstract

Electrochemical sensing techniques are considered to be highly efficient towards the detection of water pollutants. Most of these conventional electrochemical sensors utilize graphene and carbon nanotubes as a conducting material. But recent researches have documented several adverse impacts of these materials such as their toxicity, effect on ecosystem by various diseases and also their use make the sensor more costly. For the development of electro-chemical sensors, environmentally benign and sustainable natural materials are currently replacing harmful materials. In this regard this research work aims to synthesize the green nanocomposite based electrochemical sensor for the detection of water pollutants. Nano cellulose is used as a substrate. Nano cellulose was first synthesized by acid hydrolysis method. Further it was fabricated with polyaniline through in situ polymerization and metal oxide nanocomposite was incorporated in it. The synthesized composites were characterized by FTIR and XRD for structural evaluation. The electrochemical analysis of the synthesized composites was performed. The obtained analytical results of electrochemical impedance spectroscopy (EIS) suggest that both the synthesized composites (CoO/AgCl/NiO/PANI/nanocellulose and CoO/AgCl/CuO/PANI/nanocellulose) are conductive in nature. To check the sensing behavior of the synthesized composites against metal ions cyclic voltammetry was performed. Cyclic voltamogram of CoO/AgCl/NiO/PANI/nanocellulose was found to be efficient against the Pb+2 and Cd+2 ions with the limit of detection 0.5 and 0.14 mM/L respectively. Cyclic voltamogram of CoO/AgCl/CuO/PANI/nanocellulose was also obtained against Pb+2 and Cd+2 ions having better results than the bare GCE. The results suggest that modified electrodes are better conductor and have good sensitivity which can be applied for real sample analysis as electrochemical sensors.