材料期刊网

目的：研究纳米CdTe/TiO2复合材料对304不锈钢的光生阴极保护行为。方法采用阳极氧化法制备二氧化钛纳米管，通过循环伏安沉积法在纳米管上进行CdTe修饰。应用扫描电镜（SEM）、X射线衍射（XRD）等测试方法对比纯TiO2与CdTe/TiO2的表面形貌与晶相特征。结合开路电位（OCP）、光电流密度-时间曲线（J-t）、Tafel 极化曲线等电化学方法，研究复合材料的光电转化性能及其对304不锈钢的阴极保护行为。结果在光照条件下，耦连CdTe/TiO2复合材料的304不锈钢的开路电位从初始的?190 mV负移至?730 mV，光电流密度可达0.15 mA/cm2，闭光后，开路电位上升至?350 mV，仍然具有保护作用，说明制备的纳米CdTe/TiO2复合材料具有储存电子的能力。结论在可见光照射下，与纯二氧化钛相比，制备的CdTe/TiO2复合材料对304不锈钢的阴极保护性能显著提高，且在闭光状态下仍能维持对不锈钢的保护，对不锈钢起到一定的延时保护效果。

ABSTRACT:Objective To study nano-CdTe/TiO2 composite material for photogenerated cathodic protection of 304 stainless steel.Methods TiO2 nanotubes were fabricated by anode oxidation method, and the CdTe deposition was prepared in the nano-tubes by potentiodynamic deposition. By changing the acidity of the electrolyte, CdTe/TiO2 composites with the best optical properties were obtained. Scanning electron microscopy (SEM) and X ray diffraction (XRD) test were used to observe the sur-face morphology and phase characteristics of the composite materials. Using open circuit potential (OCP), amperometricJ-t curve, tafel polarization curve and other electrochemical methods, the cathodic protection of 304 stainless steel was investigated. Results Under the visible light illumination, the open circuit potential of 304 stainless steel connected with the composite ma-terial could shift from?190 mV to?730 mV. The photocurrent density could reach 0.15 mA/cm2, after the light was turned off, the OCP of 304 kept?350 mV, which was lower than its corrosion potential. It indicated that the composite material was capable of electron storage.ConclusionThe cathodic protection performance of CdTe/TiO2 composite material was significantly im-proved compared with pure TiO2 in the visible range. And it could maintain the protection of stainless steel in dark environment. Comparing with TiO2, this material had the captivity of prolonging protection of the 304 stainless steel.