Fabrication of a methanol chemical sensor based on hydrothermally prepared α-Fe₂O₃ codoped SnO₂ nanocubes.

We have prepared calcined α-Fe(2)O(3) codoped SnO(2) nanocubes (NCs) by a hydrothermal method using reducing agents in alkaline medium. The codoped NCs were characterized by UV/vis, FT-IR, and Raman spectroscopy, powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM). They were deposited on a silver electrode (AgE, surface area, 0.0216 cm(2)) to give a sensor with a fast response towards methanol in liquid phase. The sensor also exhibits good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r(2)=0.9809) over the 0.25 mmol L(-1) to 0.25 mol L(-1) methanol concentration range. The sensitivity is ∼5.79 μA cm(-2)mM(-1), and the detection limit is 0.16 ± 0.02 mmol L(-1) (signal-to-noise ratio, at a SNR of 3). We also discuss possible future prospective uses of this codoped semiconductor nanomaterial in terms of chemical sensing.