Electrochemical sensor based on Ce-MOF/carbon nanotube composite for the simultaneous discrimination of hydroquinone...

Ce-MOF/CNTs nanocomposites were prepared by a simple method and post-treated with NaOH/H₂O₂ mixed solution. The morphology and structure of the treated samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that the post treatment induces the Ce-MOF morphological changing from rod-like structure into particles, which are covered on the surface of CNTs. XPS demonstrates that there are two-valence (TV) of Ce³⁺/Ce⁴⁺ in the post-treated Ce-MOF/CNTs (TV) composite. The electrochemical behaviors of nanocomposite were also investigated on electrochemical work station. By utilization of the good electrical conductivity of CNT, the two-valence of Ce and the high surface area of MOF, the nanocomposites were used to fabricate the electrochemical sensor for the simultaneous electrochemical detection of hydroquinone (HQ) and catechol (CC). Compared to the Ce-MOF/CNTs/GCE, the post-treated Ce-MOF (TV)/CNTs/GCE exhibited two well-defined peaks for the electrochemical oxidation of HQ and CC. The linear ranges responding to HQ and CC are 10~100 μM and 5~50 μM respectively.