Characterization and photoelectrochemical performance of Zn-doped TiO_2 films by sol-gel method  

溶胶凝胶法制备Zn掺杂TiO_2薄膜的表征和光电化学行为（英文）

作　　者：Li-ying QIAO Feng-yu XIE Ming-hui XIE Cai-hua GONG Wei-lang WANG Jia-cheng GAO 乔丽英;谢奉妤;谢明辉;龚才华;王维朗;高家诚(重庆大学材料科学与工程学院,重庆400045;重庆大学国家镁合金材料工程技术研究中心,重庆400044;四川师范大学化学与材料科学学院,成都610068)

机构地区：[1]College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China [2]National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China [3]College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, China

出　　处：《Transactions of Nonferrous Metals Society of China》2016年第8期2109-2116,共8页中国有色金属学报（英文版）

基　　金：Project(cstc2011jj A50008)supported by the Natural Science Foundation of Chongqing,China;Project(14ZB0025)supported by Education Department of Sichuan Province,China

摘　　要：Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.采用溶胶-凝胶法在纯钛基体上制备Zn掺杂纳米TiO_2薄膜(Zn-TiO_2),研究不同热处理温度下Zn掺杂对纳米TiO_2薄膜的物理性能、光阴极保护效果和光电化学性能的影响。研究表明,与未掺杂TiO_2薄膜相比,Zn的加入提高了Zn-TiO_2薄膜的光电化学响应,在300°C热处理后的薄膜使金属基体的电极电位下降最大,降低了897 mV。SEM-EDS分析表明,Zn在掺杂薄膜中的分布不均匀,XRD结果显示Zn掺杂的薄膜比未掺杂的薄膜晶粒更细小。红外光谱结果表明,TiO_2晶粒表面有Zn—O键生成。紫外光谱表明,Zn掺杂使Zn-TiO 2吸收带边红移,扩大了TiO 2的光响应范围。根据Mott-Shottky曲线可知,Zn-TiO_2薄膜比纯TiO_2薄膜的平带电位更负,载流子量更大。这说明在平带电位、载流子量和空间电荷层宽度的协同作用下,300°C热处理后的Zn-TiO_2薄膜表现了最佳的光电化学响应。

关 键 词：TiO2 films Zn-doping photocathodic protection photoelectrochemical activity sol.gel method 

分 类 号：TG174.41[金属学及工艺—金属表面处理]