Semiconductor α‐Fe ₂ O ₃ Hematite Fabricated Electrode for Sensitive Detection of Phenolic Pollutants

Abstract Hematite (α‐Fe 2 O 3 ) 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‐Fe 2 O 3 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.