Abstract

The toxic vanadium (V) compounds of oil fly ash produced by power plants worldwide are posing a broad spectrum of many health threats and environmental hazards. Here, we use alkaline leaching and a simple two-step precipitation method to recycle vanadium from this industrial waste into nanostructured vanadium pentoxide (V₂O₅) for ethanol-sensing applications. The recovery of vanadium from the fly ash is maximized by applying the design of experiments based on the response surface methodology (RSM) to the fly ash leaching process. Containing small amounts of impurities such as Si, Al, Fe, and Ni, the recovered V₂O₅ shows up to 60% higher sensitivity toward ethanol than pure V₂O₅. Hence, the vanadium content of oil fly ash can be recycled into a product that holds great potential as a low-temperature ethanol sensor. This strategy not only helps mitigate the adverse effects of the landfill of the fly ash but also reduces the need for natural resources.

Graphic Abstract