关键词: 氧化镍, g-C3N4?, 电沉积, 抗坏血酸, 修饰电极

Abstract: NiO/g-C3N4 complex was successfully synthesized from NiCl2 and C3H6N6. The as-prepared NiO/g-C3N4 composite modified glassy carbon electrode by both casting method and electrodeposition showed remarkable electrocatalytic performance for ascorbic acid (AA). The peak current displayed a linear relationship with scanning rate in the range from 70 to 200 mV/s. The equations were depicted as follows: Ipa = ?34.14?1.167v, and Ipc= 53.42 + 0.357 8v, with correlation coefficients (R) equal to 0.998 and 0.982, respectively. Meanwhile, it was shown that the spike potential deviated with increasing scanning rate. This effect demonstrates that the electrochemical process was controlled by surface diffusion. The anodic current was proportional to the AA concentration and the calibration plot was Ipc= ?1.435 + 2.900C, R = 0.998, which was linear over the concentration ranges of 0.017 6 to 22.88 μg/mL. The detection limit (LOD) of the method was 0.008 8 μg/mL. Furthermore, results also showed that the sensor had good selectivity, stability and reproducibility and could be used to detect AA in juice samples with satisfactory results.

Key words: NiO, g-C3N4, electrolytic deposition, ascorbic acid, modified electrode