Semiconductor α-Fe2O3 Hematite Fabricated Electrode for Sensitive Detection of Phenolic Pollutants

Abstract

Hematite (α-Fe2O3) semiconductor is an abundant and non-toxic catalyst for different (photo)electrochemical reactions. In this work, a selective p-nitrophenol sensor was developed by fabricating a thin-layer of a glassy carbon electrode (GCE) with 5% nafion coating binders onto α-Fe2O3 thin film synthesized by a simple and inexpensive process. High sensitivity including linear dynamic range, long-term stability, and enhanced electrochemical performance towards p-nitrophenol were achieved by a reliable current-voltage method. A linear calibration curve was observed over a wide range of p-nitrophenol concentrations. Very low detection limit (0.6±0.02 nM), good limit of quantification (2.0 nM) and high sensor sensitivity (K=74.1 μA⋅cm−2) are calculated based on noise to signal ratio of ∼3 N/S. Very importantly, the detection range covers over 7 orders of magnitude concentrations, from nM to mM. Figures of merits are comparable with best reported results whilst using a very simple device configuration. We show that hematite is an excellent material for the development of chemical sensors to detect hazardous compounds for environmental safety in a broad scale of concentrations.