铁氰化镍/普鲁士蓝复合膜传感器的制备及性能研究

Study on the properties of nickel ferricyanide/prussian blue composite films electrochemical sensor

利用直接电沉积法制备了Nano-NiHCF/PB复合膜传感器.电沉积过程中EDTA同时起到了减慢金属铁氰化物成核速率、加快沉积速率的作用,使金属铁氰化物由不均匀的小岛状结块转变为立方体状并均匀分散于复合陶瓷碳电极(CCE)表面.结果表明,该复合膜并不是铁氰化镍和普鲁士蓝(PB)的简单混合,PB立方晶体中的FeШ被Ni2+占据进而生成铁、镍共沉积的铁氰化物.研究了复合膜的电化学性质及其对H2O2的电催化活性,H2O2浓度与其峰电流在7.9×10^-6~2.3×10^-2mo/L范围内呈良好的线性关系(r=0.9987),检出限为2.6×10^-6mol/L,灵敏度为77.5μA/mmol/L,异相催化反应速率常数为1.6×10^3L/mol/s.该复合材料较高的循环稳定性受益于nano-Ni/FeHCF成核点在CCE溶胶-凝胶形成的三维网状碳基底中的均匀分布.

The mixed nickel/iron hexacyanoferrates thin film was prepared on the surface of composite ceramic electrode by electrodeposition technique.The electrochemical behavior and electrocatalytic activity of the modified electrode were carefully investigated.The results showed that the presence of EDTA in deposition solution controlled the size and deposition rate of NiHCF/PB nanoparticles.The mixed material did not seem to be a simple mixture of hexacyanoferrates of nickel and iron,which showed unique voltammetric behavior when compared with the respective single-metal exacyanoferrates.The calibration curve was over the range of 7.9×10^-6 to 2.3×10^-2 mol/L with a correlation coefficient of 0.998 7,and a detection limit of 2.6×10^-6 mol/L(S/N=3) was obtained,the sensitivity was 77.5 μ A/mmol/L and the catalytic rate constant was 1.6×10^ 3 L/mol/s.Which made it possible for the constructing of biosensors.The NiHCF/PB composites exhibited good cyclic stability,which can be attributed to the uniform dispersion of MHCF in the sol-gel porous structure of CCE.