Facile formation of highly single crystalline CuV₂O₆ nanorods: Utilization for electrochemical H₂S sensing

We demonstrate a straightforward synthetic approach for fabricating single-crystalline, low-dimensional copper vanadate (CuV₂O₆) nanorods via a simple acid-base reaction in aqueous solution followed by thermal annealing at 550 ℃. These nanorods were subsequently utilized for the first time in electrochemical measurements aimed at the selective detection of toxic hydrogen sulfide (H₂S) gas. The thermal annealing of the precipitated precursors comprising Cu(OH)₂ and V(OH)₃ readily induced the transformation from amorphous metal hydroxides to highly crystalline CuV₂O₆ nanorods through a simple dehydration-driven crystallization process. The resulting single crystalline bimetallic oxide, with its uniform low-dimensional structure, significantly enhances the electrochemical oxidation of H₂S gas due to a relatively large electrochemical surface area (ESA). Despite its nanoscale dimensions, CuV₂O₆-2h exhibited a notably high ESA, which correlated well with its superior H₂S sensing performance. Electrochemical studies confirmed that the nanorods achieved a sensitivity of 2.6₅ nA μM⁻¹ with 0.69₉ μM LOD with excellent selectivity for H₂S gas detection. These results suggest that CuV₂O₆ nanorods hold strong potential as an effective electrode material for amperometric H₂S sensors.