Simple strategy synthesis of manganese cobalt oxide anchored on graphene oxide composite as an efficient electrocatalyst for hazardous 4-nitrophenol detection in toxic tannery waste

Abstract

Hazardous 4-nitrophenol (4-NP) and its isomers are very harmful to humans, plants, and animals even at very low concentrations. Consequently, it is very urgent and essential to identify 4-NP in the environment with a simple and accurate method. Herein, MnCo2O4 (MCO) nanosphere was synthesized by simple co-precipitation process using sodium hydroxide as a precipitating agent and subsequent elimination by calcination. The MCO@GO is prepared by ultrasound irradiation at room temperature. Graphene oxide was anchored with MCO nanospheres were performed excellent electrocatalytic activity owing to their Mn2+/Mn3+ and Co2+/Co3+ have an impressive synergistic effect (MCO) and large active surface area (GO). The prepared MCO@GO nanocomposite was characterized by different analytical techniques namely XRD (crystal nature), FTIR (functional group), FESEM, TEM (morphological analysis), XPS (elemental state). The electrochemical characterization was monitored by CV and DPV. The MCO@GO nanocomposite was drop cast on a glassy carbon electrode is referred to as MCO@GO/GCE for the electrochemical determination of 4-NP with good practical applicability. The peak current was increased while increasing the concentration of 4-NP from 0.5 µM to 151.5 µM with a regression equation y = 0.4952(µM) + 3.092 and correlation coefficient R2 = 0.9921. From this slope value, the LOD and sensitivity were determined to be 0.012 µM and 6.868 μA μM−1 cm−2. The sensor was successfully used for practical application of the 4-NP determination in toxic tannery wastes with a strong agreement with the added value and the recovery results. The objective of our work has afforded to readers a thorough understanding of the synthesis and electrochemical sensing applications of MCO@GO and some guidance in future research.