ZnFeAl-layered double hydroxides/TiO2 composites as photoanodes for photocathodic protection of 304 stainless steel

Xiu-Tong Wang; Xiao-Bo Ning; Qian Shao; Sheng-Song Ge; Zhi-Ying Fei; Jing Lei; Bao-Rong Hou

doi:10.1038/s41598-018-22572-7

ZnFeAl-layered double hydroxides/TiO₂ composites as photoanodes for photocathodic protection of 304 stainless steel

Sci Rep. 2018 Mar 7;8(1):4116. doi: 10.1038/s41598-018-22572-7.

Authors

Xiu-Tong Wang^{1

2}, Xiao-Bo Ning^{3

4

5}, Qian Shao⁴, Sheng-Song Ge⁴, Zhi-Ying Fei⁴, Jing Lei^{3

4

5}, Bao-Rong Hou^{3

5}

Affiliations

¹ Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China. xiutongwang@gmail.com.
² Open Studio for Marine Corrosion and Protection, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China. xiutongwang@gmail.com.
³ Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
⁴ College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
⁵ Open Studio for Marine Corrosion and Protection, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.

Abstract

A series of ZnFeAl-layered double hydroxides/TiO₂ (ZnFeAl-LDHs/TiO₂) composites are synthesized by a combined anodization and hydrothermal method. The structure, surface morphology, photo absorption and photocathodic protection properties of these samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) and electrochemical tests. The unique structure of the ZnFeAl-LDHs reduces the charge carriers recombination, and the visible photoresponse property increase the light harvesting. The XPS study reveals that the electrons in the ZnFeAl-LDHs travel to TiO₂, and the ZnFeAl-LDHs/TiO₂ composites generate and transfer more electrons to 304 stainless steel (304SS), and exhibits a better photocathodic protection performance than pure TiO₂. In addition, after intermittent visible-light illumination for four days, the photoanode still exhibits good stability and durability.