Fabrication of Co3O4 nanoparticle-decorated porous activated carbon electrode for the electrochemical detection of 4-nitrophenol

Abstract

State-of-the-art electrochemical applications have recently employed various activated carbons combined with transition metal oxides as electrode materials, which exhibit superior conductivity and tailored porosity to offer rapid electron transfer. In this study, Bauhinia vahlii dead fruit-derived carbon (BVFC) integrated with cobalt oxide (Co₃O₄) nanoparticles was used to detect 4-nitrophenol (4-NP). The Co₃O₄@BVFC composite was characterized using various spectral and analytical techniques, including XRD, Raman, BET, TGA, FE-SEM, TEM and XPS. Under optimum experimental conditions, the Co₃O₄@BVFC-modified GCE revealed a wide linear range (0.01–140 μM), a low detection limit (5 nM), and high sensitivity (18.236 μA μM⁻¹ cm⁻²) towards 4-NP detection with considerable selectivity. The excellent sensing ability of the composite was mainly due to the higher surface area and the synergistic effect between Co₃O₄ and BVFC. Furthermore, the Co₃O₄@BVFC-modified GCE applied in the real-time analysis of 4-NP in water bodies showed satisfactory recovery results (±96.50–98.60%). Results show that Co₃O₄@BVFC is a good candidate for 4-NP detection.