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

We have prepared calcined α-Fe2O3 codoped SnO2 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 cm2) 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 (r2 = 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.