Preparation of SnIn4S8/TiO2 Nanotube Photoanode and Its Photocathodic Protection for Q235 Carbon Steel Under Visible Light

Hong Li,Baorong Hou,Pengfei Zhang,Weizhe Song,Yanhui Li,Lianjun Cheng,Xingqiang Cui

doi:10.1186/s11671-020-03447-1

Abstract

TiO2 is an attractive semiconductor suitable for photocathodic protection, but its weak absorption of visible light and low quantum yield limit its usage. Here, a new heterostructured SnIn4S8 nanosheet/TiO2 nanotube photoanode was prepared and its photocathodic protection performance was analyzed. SnIn4S8 nanosheets were uniformly deposited on the surface of the TiO2 nanotube via a solvothermal treatment. The SnIn4S8/TiO2 composite exhibited better photocathodic protection performance compared with pure TiO2 nanotubes, owing to its good visible-light response and photogenerated carrier separation efficiency. Moreover, the composite exhibited a maximum photocurrent density of 100 μA cm−2 for a 6 h solvothermal reaction under visible light irradiation. The negative shift of the photoinduced potential of Q235 carbon steel connected to the composite could reach 0.45 V versus SCE. Therefore, the SnIn4S8/TiO2 composite can offer efficient photocathodic protection for Q235 carbon steel against corrosion in 3.5 wt% NaCl solution. This work provides a new approach for the development of high-efficient photoanode materials for the photocathodic protection of metals.

Highlights

With the high-speed growth of industrial technology, metal corrosion has become a global problem [1, 2]
The nanostructure composed of thin nanosheets and large hierarchical pores was conducive to the improvement of the light harvestability due to multiple light scattering, which may facilitate the charge transfer in the Figure 3 shows the X-ray diffraction (XRD) spectra of the synthesized TiO2 and the SnIn4S8/TiO2 composite films
Compared with pure TiO2, three other diffraction peaks were observed in the XRD spectra of the Stannum indium sulfide (SnIn4S8)/TiO2 composites

Summary

Introduction

With the high-speed growth of industrial technology, metal corrosion has become a global problem [1, 2]. Metal corrosion shortens the service life of the equipment and causes huge economic losses, even catastrophic safety accidents and environmental problems. Q235 carbon steel (CS) is prone to severe corrosion in NaCl solution [3]. Photocathodic protection is an environmentally friendly and costsaving technology with great application potential for metal anti-corrosion [4], which uses clean solar energy unlike conventional anti-corrosion technology. Semiconductor photoanode materials are not consumed like traditional sacrificial anodes.

Methods

Results

Conclusion