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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。
The Zn-doped TiO 2 thin films (Zn-TiO 2) were prepared on pure titanium substrates by sol-gel method, and the effects of Zn doping on the physical properties, photocathode protection and photoelectrochemical properties of the TiO 2 thin films were studied under different heat treatment temperatures . The results show that the addition of Zn improves the photoelectrochemical response of the Zn-TiO 2 thin film compared with that of the undoped TiO 2 thin film. The thin film after 300 ° C heat treatment can reduce the electrode potential of the metal substrate to the maximum by 897 mV. SEM-EDS analysis showed that Zn was not uniformly distributed in the doping films. XRD results showed that Zn-doped films were finer than undoped ones. The results of FTIR showed that Zn-O bond was formed on the surface of TiO 2 crystal. UV spectroscopy showed that Zn doping shifted the band edge of the Zn-TiO 2 band to the red side, expanding the photoreaction range of TiO 2. According to the Mott-Shottky curve, the Zn-TiO 2 thin film is more negative than the pure TiO 2 thin film and has a larger carrier carrying capacity. This shows that the Zn-TiO 2 films annealed at 300 ° C show the best photoelectrochemical response under the synergetic effect of flat band potential, carrier and space charge width.