Development of mixed spinel metal oxide (Co-Mn-O) integrated functionalized boron nitride: Nanomolar electrochemical detection of herbicide diuron

Abstract

The crystal phase influences the electrochemical activity of electrode materials. In particular, mixed phases contain metal ions with different oxidation states which enable conductivity and enhance the electrochemical activity. Moreover, 2D nanomaterials enhance the adsorption of target molecules owing to their surface properties. Based on that, the nanocomposite of mixed spinel metal oxide [Co, Mn oxides (CMO NPs)]/and functionalized boron nitride (f-BN) was prepared first time for the electrochemical sensor applications towards herbicide diuron determination. The CMO NPs/f-BN composite has been confirmed by various spectroscopic and microscopic analyses such as p-XRD, FT-IR, FE-SEM, and HR-TEM techniques. p-XRD and FTIR analysis proved the formation of mixed spinel of Co, Mn oxides. Interestingly, morphological investigations revealed that CMO NPs formed as an irregular cubic shape with ± 120 nm in size and f-BN existed in lateral flake-like morphology. FT-IR exhibits, that functionalization promotes the transmittance of functional groups (-OH) of h-BN. The CMO NPs/f-BN/GCE exhibits the well-resolved DU oxidation peak in the CV experiments, owing to the synergetic effect between the CMO NPs and well-functionalized f-BN. In addition, CMO NPs/f-BN/GCE exhibits a low detection limit of 13 nM along with a sensitivity of 0.323 μA µM−1 cm−2 between the two linear ranges of 0.01–419 µM and 569–1770 µM. The proposed sensor showed good repeatability, reproducibility, and stability in DPV analysis. The fabricated DU sensor was successfully applied to real sample analysis in environmental water samples with acceptable recovery results, suggesting CMO NPs/f-BN composite as a beneficial electrode material for the determination of DU.