纳米TiO_2/SnO_2涂层的制备与光阴极保护性能

Preparation and Photo-Cathodic Protection Properties of Nano-Sized TiO_2/SnO_2 Coatings

采用溶胶-凝胶法在304不锈钢表面制备了纳米TiO2/SnO2叠层涂层.通过测量稳定电位研究了涂层的光电化学性能和光阴极保护特性,用扫描电子显微镜、X射线衍射和X射线光电子能谱对涂层的表面形貌、晶体结构与组成进行了表征.结果表明:纳米TiO2表层与纳米SnO2内层分别浸渍提拉4次制得的叠层涂层具有最好的光电化学效应、储存电子性能与光阴极保护作用,紫外光照1 h的延时阴极保护作用可达7 h;纳米叠层涂层表面连续、均匀致密;TiO2为锐钛矿型,SnO2为金红石型;涂层表面与内层均由Ti、Sn、O和C元素组成.文中还探讨了纳米TiO2/SnO2叠层涂层的光阴极保护作用机理.

Nano-sized double-layer TiOJSnO2 coatings were prepared on Type 304 stainless steel substrate via the sol-gel method. The ＂photo-electrochemical effect and photo-cathodic protection properties of the coatings were then investigated by measuring the stable potential. Moreover, the surface morphology, structure and composition of the prepared coatings were characterized by means of SEM, XRD and XPS. The results show that （1） the nano-sized double-layer TiOz/SnO2 coatings prepared by dipping TiO2 and SnO2 coatings respectively for 4 times are of the best photo-electrochemical effect, charge-storage capability and photo-cathodic protection properties, which provides the coated Type 304 stainless steel with a cathodic protection lasting 7 h after the irradiation by UV illumination for 1 h ; （2） the coatings are uniform and compact, with continuous surface, anatase TiO2 and rutile SnO2; and （3） both the outer and the inner layers of the coatings are composed of Ti, Sn, C and O. The mechanism of photo-cathodic protection of the nano-sized TiO2/SnO2 coatings is also discussed in the paper.