Simultaneous Electrochemical Determination of Catechol and Hydroquinone Using a Flower-Like Ni-Al Layered Double Hydroxide/Carbon Black Nanocomposite-Modified Electrode

We have developed a Ni-Al layered double hydroxide (LDH) and carbon black (CB) composite for the selective electrochemical detection of hydroquinone (HQ) and catechol (CT). LDH exhibits multiple active sites and high adsorption capacity for phenolic substances. CB demonstrates high conductivity and electrocatalytic capacity. The crystal structure was characterized by X-ray diffraction, establishing the successful synthesis of flower-like LDH, and the successful combination of LDH and CB. Fourier-transform infrared spectroscopy confirmed that the LDH surface contained sufficient hydroxyl groups to adsorb CT and HQ. The morphology of LDH/CB was characterized by scanning electron microscopy, and the composition and valence confirmed by X-ray photoelectron spectroscopy. The LDH/CB sensor delivered excellent performance in terms of sensing HQ and CT, with a wide detection range (0.1–150 μM) and detection limits of 0.011 and 0.0091 μM (DL = 3.3σ/S), respectively. The excellent performance of this sensor makes it a reliable choice for detecting HQ and CT in water.