Preparation of Fe₃O₄/MWCNT nano-hybrid and its application as phenol sensor

In this work, Fe₃O₄/MWCNT nano-hybrid was successfully fabricated. Its composition, structure and morphology were characterized by XRD and TEM and the results suggested that Fe₃O₄ nanoparticles with cubic structure was smoothly dispersed on MWCNT surface. Electrochemical impedance spectra (EIS) showed that Fe₃O₄/MWCNT presented excellent electron transfer behavior. The electrochemical determination of phenol in phosphate buffer solution (pH 7.4) revealed that Fe₃O₄/MWCNT modified GC electrode (Fe₃O₄/MWCNT/GCE) exhibited superior catalytic activity toward phenol with a linear equation of i _pa (μA) = −0.018 − 0.034c (μmol/L) R = 0.9990 in a wide range from 5 to 235 μM. The detection limit was calculated to be 4.83 μM (S/N = 3) and a high sensitivity of 481.2 μA mM⁻¹ cm⁻² was achieved from the equation slope. This electrocatalyst also showed a short response time and high anti-interference to ethanol. The wide detection range, fast response, low detection limit, high sensitivity and anti-interferance of Fe₃O₄/MWCNT endowed it with potential application in electrochemical detection of phenol. (paper)