Phenolic sensor development based on chromium oxide-decorated carbon nanotubes for environmental safety

A nanocomposite (NC) composed of chromium(III)oxide nanomaterials decorated carbon nanotubes (Cr2O3–CNT NC) was prepared via a simple solution method with reducing agents in an alkaline medium. The Cr2O3–CNT NC was characterized using ultraviolet–visible (UV/Vs.) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (XEDS), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FESEM). The Cr2O3–CNT composite was deposited on a flat glassy carbon electrode (GCE) with conducting nafion (5%) binders to produce a sensor that exhibited fast response and high selectivity toward 4-methoxyphenol (4MP) in phosphate buffer phase at pH 7. Furthermore, the sensor performance parameters, including the sensitivity, lower detection range, reliability, and reproducibility, ease of integration, long-term stability, and selectivity were investigated in detail. The calibration plot was found to be linear in the concentration range of 0.01 nM–0.1 μM. The sensitivity and detection limit were calculated as 1.4768 μA cm−2 μM−1 and 0.06428 ± 0.0002 nM (at a signal-to-noise ratio of 3), respectively. Thus, it was concluded that the proposed selective and efficient sensor represents a promising approach to effectively detect toxic phenolic compounds in the environment with acceptable and reliable results. [Display omitted] •Cr2O3- CNT nanocomposite was prepared by solution method.•A fast response towards 4-methoxyphenol was developed.•Sensor sensitivity was 1.4768 μA cm−2 μM−1.•Sensor detection limit was 0.06428 ± 0.0002 nM.•Environmental safety.