Alizadeh Taher, Nayeri Sahar, Hamidi Negin
Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran P. O. Box 14155-6455 Tehran Iran
Department of Applied Chemistry, Faculty of Science, University of Mohaghegh Ardabili Ardabil Iran.
RSC Adv. 2019 Apr 29;9(23):13096-13103. doi: 10.1039/c9ra00982e. eCollection 2019 Apr 25.
Nanosized graphitic carbon nitride (nano-g-CN) was synthesized using the thermal polymerization of melamine and utilized as a novel electrocatalyst for electrooxidation of oxalic acid (OA). The nano-g-CN was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The electrocatalytic performance of the g-CN-modified carbon paste electrode (g-CN/CPE) was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode showed excellent electrocatalytic activity towards the oxidation of OA. The effects of electrode composition, pH and scan rate on the electrooxidation response of OA were studied. Under optimized conditions, the differential pulse voltammetric response of the electrode was linearly related to OA concentrations between 1 and 1000 μM, with a limit of detection (LOD) of 7.5 × 10 M. The electrode exhibited very high sensitivity of 1945 μA mM cm for OA assay. The developed method was successfully applied for the determination of OA in urine samples with satisfactory results.
采用三聚氰胺热聚合的方法合成了纳米尺寸的石墨相氮化碳（nano-g-CN），并将其用作草酸（OA）电氧化的新型电催化剂。通过傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）和场发射扫描电子显微镜（FE-SEM）对nano-g-CN进行了表征。采用循环伏安法和电化学阻抗谱（EIS）研究了g-CN修饰碳糊电极（g-CN/CPE）的电催化性能。修饰电极对OA的氧化表现出优异的电催化活性。研究了电极组成、pH值和扫描速率对OA电氧化响应的影响。在优化条件下，电极的差分脉冲伏安响应与1至1000 μM之间的OA浓度呈线性关系，检测限（LOD）为7.5×10⁻⁶ M。该电极对OA检测表现出1945 μA mM⁻¹ cm⁻²的极高灵敏度。所建立的方法成功应用于尿样中OA的测定，结果令人满意。
