Hydrothermal Preparation of Manganese Dioxide/Sulfur Doped Reduced Graphene Oxide and Construction of 4-Nitrotoluene Sensor

Nitro-groups containing compounds are widely used in various applications but are considered highly toxic compounds. 4-nitrotoluene (4NT) belongs to the nitro-aromatic compounds and is a highly hazardous water contaminant. Thus, exploring new materials with excellent physiochemical and electrochemical properties is desirable for the construction of efficient 4NT sensors. The present study reports the fabrication of manganese dioxide/sulfur-doped reduced graphene oxide (α-MnO2/S@rGO) via hydrothermal synthesis procedure. The well-characterized α-MnO2/S@rGO was employed as a catalyst for the construction of α-MnO2/S@rGO modified screen printed carbon electrode (SPCE) for the detection of 4NT using cyclic voltammetry (CV). The α-MnO2/S@rGO modified electrode exhibits good electro-catalytic properties for the detection of 4NT compared to the bare SPCE, α-MnO2-, or S@rGO-modified electrodes. A reasonable detection limit of 0.5 µM with sensitivity of 1.97 µA.µM-1.cm-2 was obtained using α-MnO2/S@rGO modified electrode. The α-MnO2/S@rGO modified electrode demonstrated considerable selectivity for the sensing of 4NT in presence of various electro-active species. Note that the combination of catalytic α-MnO2 and conductive S@rGO present excellent synergistic interactions which improved the performance of the α-MnO2/S@rGO-modified electrode.