Noble-metal-free single-phase Co₃V₂O₈ with the structural integrity of nanofibers for the selective detection of ascorbic acid

We report the facile fabrication of single-phase bimetallic oxide Co₃V₂O₈ nanofibers with a tubular morphology prepared by electrospinning and subsequent thermal annealing processes, and carefully investigate the electrochemically fundamental measurements for the selective electrochemical detection of ascorbic acid (AA) for the first time. Particularly, single-phase Co₃V₂O₈ with the specific oxidation states of Co and V preserves the structural integrity of nanofibers despite the disparate thermal decomposition properties between the metal precursors and polymer matrix. Furthermore, as noble-metal-free electrocatalysts with tubular morphology, the Co₃V₂O₈ nanofibers exhibit high electrocatalytic activity for the oxidation of ascorbic acid (AA). The designed bimetallic oxide Co₃V₂O₈ nanofibers with compositional homogeneity revealed a large electrochemical surface area, which has great beneficial merit in enhancing the electrocatalytic AA oxidation compared to that with pure metal oxides (Co₃O₄ and V₂O₅). Considering that low-cost metal oxides are promising electrocatalytic materials for practical applications, the as-prepared Co₃V₂O₈ nanofibers with feasible AA sensing capability (sensitivity of 82.16 μA mM⁻¹ cm⁻²) could be one of the candidates to resolve the utilization of catalysts that have been previously restricted by the high cost and scarcity of noble metals.