Abstract In this study, polypyrrole (PPy)/TiO2 core-shell nanorods (PTNRs) films were successfully synthesized through hydrothermal treatment and electrochemical polymerization method. The structure and optical properties of the as-prepared films were characterized. The results showed that the core-shell PTNRs film exhibits superior visible-light absorption ability. The composite films with different deposition conditions were systematically studied on the performance of the photocathodic protection (PCP). The photoelectrochemical performance of the samples are related to their structures which are strongly influenced by the deposition time of PPy layer. Meanwhile, compared with other reported as-prepared films, PTNRs film under visible light illumination could negatively shift the potential of the coupled 304 stainless steel (304SS) to -640 mV vs. Ag/AgCl, exhibiting more efficient PCP effect. More importantly, it can continuously provide protection for the steel in the darkness based on the electron pool effect of PPy. The possible PCP mechanism of PTNRs film was also discussed.

中文翻译：

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PPy/TiO2核壳纳米棒薄膜的制备及其对304不锈钢可见光的光阴极保护

摘要 本研究通过水热处理和电化学聚合方法成功合成了聚吡咯（PPy）/TiO2核壳纳米棒（PTNRs）薄膜。表征了所制备薄膜的结构和光学性能。结果表明，核壳 PTNRs 薄膜表现出优异的可见光吸收能力。系统研究了不同沉积条件下复合薄膜的光阴极保护（PCP）性能。样品的光电化学性能与其结构有关，其结构受 PPy 层沉积时间的强烈影响。同时，与其他报道的制备的薄膜相比，可见光照射下的 PTNRs 薄膜可以将耦合的 304 不锈钢（304SS）的电位负移至 -640 mV，而 Ag/AgCl，表现出更有效的 PCP 效应。更重要的是，基于PPy的电子池效应，它可以在黑暗中持续为钢铁提供保护。还讨论了 PTNRs 薄膜可能的 PCP 机制。