Polythiophene-sensitized TiO 2 nanotube arrays for photo-generated cathodic protection of 304 stainless steel
- PDF / 2,168,148 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 63 Downloads / 205 Views
Polythiophene-sensitized TiO2 nanotube arrays for photo-generated cathodic protection of 304 stainless steel Yong Xu1, Weiwei Zhang1,*
1
, Weizhuo Yu1, Jianxu Ding1, and Haiqing Sun1
College of Materials and Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, People’s Republic of China
Received: 16 May 2020
ABSTRACT
Accepted: 2 November 2020
TiO2 nanotube arrays (TNAs) with highly ordered three-dimensional structure are a promising alternative in photo-generated cathodic protection. Organic semiconductor polythiophene (Pth)-sensitized TNAs nanocomposite was synthesized by a two-step anodic oxidation and electrochemical anodic polymerization methods in this work. The crystalline phase, morphology, optical property and photoelectrochemical performance of Pth/TNAs samples with different polymerization times were investigated. Light absorption of Pth/ TNAs samples improves with appropriate Pth deposition that increases the density of photo-generated charge carriers. Meanwhile, Pth deposition induces improvement in the inner electric field that drives electron transfer from semiconductor to the connected metal. Increased carrier separation and heterojunction barrier effects in Pth/TNAs/Ti/304 SS multiple interfaces enhances the photoelectrochemical performance of the photoanode that leads to excellent protection effect of 304 stainless steel with irradiation. Moreover, electrons reflux from metal corrosion will be retarded for the unidirectional continuity of electrons in heterojunction barriers without irradiation, which shows application potentials in photo-generated cathodic protection in dark.
Published online: 16 November 2020
Ó
Springer Science+Business
Media, LLC, part of Springer Nature 2020
Introduction Metal corrosion is an urgent issue to be solved for industrial development [1–3]. Recently, researchers have found that some semiconductors could provide
photo-generated cathodic protection for metals under illumination [4–7]. TiO2 has been regarded as a good candidate for cathodic protection due to its high Fermi level, non-toxicity, low cost and chemical stability [8–10]. When TiO2 is irradiated with light in
Handling Editor: Joshua Tong
Address correspondence to E-mail: [email protected]
https://doi.org/10.1007/s10853-020-05528-z
4471
J Mater Sci (2021) 56:4470–4483
suitable wavelength, electrons in valence band (EVB) will be excited to the conduction band (ECB). If the TiO2 is connected electrically with metal, the excited electrons will then transfer to the coupled metal [5, 11]. Thus, the corrosion of metal will be inhibited as the metal potential shift to immunity range [12, 13]. However, the application of TiO2 remains being restricted for the weak capability of light absorption, low quantum efficiency and poor unavailability in dark [14, 15]. Recently, TiO2 nanotube arrays (TNAs) have attracted much attention due to their highly ordered three-dimensional structure, which can increase the reflection of light within the nanotubes, thereby promoting the o
Data Loading...
