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

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.