Fabrication of Mechanically Alloyed Super Duplex Stainless Steel Powder-Modified Carbon Paste Electrode for the Determination of Methylene Blue by the Cyclic Voltammetry Technique

Alloys with an equal balance of ferrite and austenite provide super duplex stainless steel (DSS) with enhanced strength and corrosion resistance. This study utilized mechanical alloying to produce nanostructured super duplex stainless steel powders for the identification of methylene blue dye in wastewater. High-energy particle grinding was employed to create the SAF-2507 DSS powders. To electrochemically oxidize methylene blue dye in wastewater, a modified carbon paste electrode (DSS-MCPE) was developed. Methylene blue, a water-soluble cationic colorant extensively used in the paper, pulp, and textile industries, poses a threat to human health and water supplies when improperly disposed of. DSS-MCPE demonstrated a significant current response, indicating its capability to detect methylene blue dye in a pH range of 6-8. The experiment revealed that 2 mg of DSS-MCPE produced a maximum current response of 72.22 μA, facilitating the effective electrooxidation of methylene blue dye in wastewater. Furthermore, the investigation demonstrated that the active surface area of the 2 mg of DSS-MCPE (0.478 cm²) was greater than that of the bare carbon paste electrode (BCPE) (0.054 cm²). The increased active surface area was correlated with an enhanced current response. The strong interaction between methylene blue molecules at the interface of the produced 2 mg of DSS-MCPE contributed to the observed increase in anodic current across methylene blue concentrations ranging from 0.1 to 0.6 mM.