Synthesis of NiO–CeO2 nanocomposite for electrochemical sensing of perilous 4-nitrophenol

Well-crystalline NiO–CeO2 nanocomposites have been fabricated by ignition method and investigated by X-ray diffraction, Fourier Transform Infrared, UV–Vis diffuse reflectance spectroscopy, Thermal gravimetric analysis, BET surface area, and transmission electron microscopy. The detailed characterizations disclosed that the pre-calcine (700 °C) nanocomposite (NCC) has two pure phases: cubic fluorite phase (CeO2) and cubic face-centered phase (NiO). Finally, the pre-calcine NCC nanocomposite was applied as electron intermediators for the electrochemical sensing of 4-nitrophenol (4-NP). Compared with as-grown modified electrode (NCG/GCE), pre-calcine electrode (NCC/GCE) exhibited more excellent conductivity and better electrocatalytic mediator for 4-NP. It was found that the NCC/GCE sensor displayed diffusion-controlled kinetics and excellent sensitivity (3.68 AμM−1 cm−2). The reduction current is directly proportional to the 4-NP concentration, ranging from 1 to 20 μM with lower detection limit of 2.48 μM.