3D ZnIn2S4 nanosheets/TiO2 nanotubes as photoanodes for photocathodic protection of Q235 CS with high efficiency under visible light

doi:10.1016/j.jallcom.2018.09.027

Journal of Alloys and Compounds

Volume 771, 15 January 2019, Pages 892-899

https://doi.org/10.1016/j.jallcom.2018.09.027 Get rights and content

Highlights

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TiO₂ nanotubes were decorated with ZnIn₂S₄.
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The composite can provide an effective protection for Q235 CS under visible light.
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Synthesis of the functionally most useful composite is described.
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The sensitization suppresses the recombination of electron−holes pairs.

Abstract

A 3-dimensional ZnIn₂S₄/TiO₂ nanotubes composite was prepared by a combined hydrothermal reaction and electrochemical anodization method. Photogenerated open circuit potential, photogenerated current density, electrochemical impedance spectra, Tafel curves, and i-V curves were measured to investigate the photoelectrochemical activities and photocathodic protection properties for Q235 carbon steel. The results showed that the photocurrent density of the ZnIn₂S₄/TiO₂ composite was greatly increased compared with pure TiO₂. Under visible light irradiation, the photocurrent density of the ZnIn₂S₄-0.25/TiO₂ composite can reach 400 μA cm⁻², which was two times that of TiO₂. The photogenerated potential drop of the composite photoanode was about 0.36 V, which was greater than that of TiO₂ (about 0.16 V). The introduction of the ZnIn₂S₄ improved the visible light absorption ability and photogenerated charge separation efficiency of TiO₂. The loading of ZnIn₂S₄ onto the TiO₂ surface led to a negative shift of the Fermi level of TiO₂. The generation of adsorbed oxygen can facilitate the separation of photogenerated charges.

Introduction

With the rapid development of modern industry, metal materials and structural materials made of metals have severe corrosion problems. Metal corrosion is extremely hazardous. The annual economic losses caused by metal corrosion in China account for about 3.34% of the gross domestic product, and about 25% of corrosion losses can be lowered through effective anti-corrosion measures. The metal ions produced by the corrosion process may cause environmental pollution. Therefore, it is of great significance to improve the corrosion resistance of metals. Q235 carbon steel (CS) is widely used for offshore equipment because of its low cost and high strength. However, Q235 CS has suffered severe corrosion in the marine environment, which directly affected the useful life of marine facilities.

Photoelectrochemical cathodic protection technology is a kind of green corrosion protection method [1]. Its principle is that when n-type semiconductor is irritated by the sunlight and the energy of the sunlight is higher than that of the semiconductor, photoinduced electrons are transferred from the conduction band (CB) of semiconductor to the metal surface and have an inhibitory effect on metal corrosion. During the application of this technology, the semiconductor photoanode material itself is not consumed and can be recycled because the anodic reaction is oxidation of water or adsorbed organic species by photoinduced holes [2]. In addition, this kind of technique can use solar energy which is a powerful, clean, endless and reliable source of energy. Therefore, photocathodic protection technique is a metal corrosion protection technology with broad prospects.

Since Tsujikawa et al. [2] applied semiconductor materials to the corrosion protection of metals, photoelectrochemical cathodic protection technology has received extensive attention from scholars at home and abroad. TiO₂ is widely studied due to its stability, environmental friendliness, and low cost. However, there are still many problems in the practical research of TiO₂ on metal protection. First, TiO₂ can only absorb ultraviolet (UV) light because of its wide band gap (about 3.2 eV) [3] and TiO₂ has low utilization of sunlight. Second, due to the positive TiO₂ CB position, TiO₂ has a relatively poor metal protection effect against metal with a negative corrosion potential. Third, since TiO₂ electrons and holes are easily recombined, the light quantum efficiency is low, resulting in a decrease in the protective performance. Therefore, we need to modify TiO₂. The development of high-efficiency visible-light-responsive TiO₂ materials is of great significance for advancing the practical application of photoelectrochemical cathodic protection technology.

Recently, construction of heterojunction photoanodes (such as NiO/TiO₂ [4], ZnO/TiO₂ [5], Ag₂S/TiO₂ [6], NiSe₂/TiO₂ [7], WO₃/TiO₂ [8,9], g-C₃N₄/TiO₂ [10,11], and Pt/CdS-TiO₂ [12]) is an effective way to broaden the light absorption range and improve the photogenerated carrier separation efficiency, resulting in improved photoelectrochemical cathodic protection property of TiO₂ [[13], [14], [15]]. However, these reports are mostly about the photoelectrochemical cathodic protection of modified TiO₂ heterojunction composites on 304 stainless steel, and less research on Q235 CS with negative potentials.

ZnIn₂S₄, a ternary chalcogenide with a narrow band gap (2.34–2.48 eV), has good stability and high catalytic activity under visible light irradiation [16,17]. However, photogenerated electrons and holes are easily recombined, resulting in low quantum efficiency [18]. The use of one-dimensional (1D) TiO₂ nanotubes (NTs) and two-dimensional (2D) ZnIn₂S₄ nanosheets to form a 3D heterojunction structure can not only improve light absorption, but also increase the specific surface area, thereby enhancing the photogenerated charge transfer efficiency and improving photoelectrochemical cathodic protection performance.

In this study, a novel 3D ZnIn₂S₄/TiO₂ nanotube heterojunction composite were successfully prepared by assembling 2D ZnIn₂S₄ nanosheets onto the surface of 1D TiO₂ NTs. Electrochemical tests including photogenerated open circuit potential (OCP) and photocurrent density changes under visible light illumination were used to study the photocathodic protection properties of 3D ZnIn₂S₄/TiO₂ composite. Electrochemical impedance spectra (EIS), Tafel curves, and i-V curves were measured to investigate the photoelectrochemical activities of the composite. The photocathodic protection mechanism of the ZnIn₂S₄/TiO₂ composites for Q235 CS under visible light illumination was also discussed.

Section snippets

Preparation of ZnIn₂S₄/TiO₂ NTs and Q235 CS electrodes

Fig. 1a displays the preparation procedure of the ZnIn₂S₄/TiO₂ NTs composites. TiO₂ NTs were firstly prepared on a Ti substrate (99.7%, 1 × 3 cm) with Pt foil as counter electrode (CE) in an ethylene glycol solution containing 6 vol% H₂O and 0.5 wt% NH₄F at 30 V for 30 min. The anodized Ti substrate was calcined at 450 °C for 2 h. And then the TiO₂ NTs were obtained.

The ZnIn₂S₄/TiO₂ NTs composites were then fabricated by a facile hydrothermal method. Typically, Zn(NO₃)₂·6H₂O (0.125–0.50 mmol),

Crystal structure and morphology

Fig. 2 shows the XRD patterns of all the prepared TiO₂ NTs samples. For pure TiO₂, the main diffraction peaks located at 25.3° (101), 37.8° (004), 53.9° (105), and 62.7° (204) were indexed to the anatase TiO₂ phase (JCPDS 21-1272). For the ZnIn₂S₄/TiO₂ samples, apart from the peaks of anatase TiO₂, two additional peaks were observed at 27.8° and 47.2°, which were indexed to (102) and (110) planes of hexagonal ZnIn₂S₄ (JCPDS 65-2023), respectively. Additionally, the peaks of TiO₂ were not

Conclusions

A 3D ZnIn₂S₄/TiO₂ nanotubes composite was successfully prepared by a combined hydrothermal reaction and electrochemical anodization method. The 3D ZnIn₂S₄/TiO₂ nanotubes composite can be used as a new photoanode material and provide photogenerated cathodic protection for metals under visible light illumination. The photocurrent density of the ZnIn₂S₄-0.25/TiO₂ composite can reach 400 μA cm⁻² and the photogenerated potential drop of the composite photoanode was about 0.36 V, indicating the

Acknowledgements

This work was financially supported by National Natural Science Foundation of China (51801109), Natural Science Foundation of Shandong Province of China (ZR2018BEM004), Taishan Scholars Construction Engineering of Shandong province (201511029), and Shandong Province Postdoctoral Innovation Project (201601001).

References (34)

Y.F. Zhu et al.
Photocathodic protection properties of three-dimensional titanate nanowire network films prepared by a combined sol-gel and hydrothermal method
Electrochem. Commun.
(2010)
N.S. Kolobov et al.
UV-LED photocatalytic oxidation of carbon monoxide over TiO₂ supported with noble metal nanoparticles
Chem. Eng. J.
(2017)
C. Han et al.
Preparation of NiO/TiO₂ p-n heterojunction composites and its photocathodic protection properties for 304 stainless steel under simulated solar light
J. Alloys Compd.
(2017)
H.M. Xu et al.
Preparation of porous TiO₂/ZnO composite film and its photocathodic protection properties for 304 stainless steel
Appl. Surf. Sci.
(2014)
X.B. Ning et al.
Preparation and photocathodic protection property of Ag₂S-TiO₂ composites
J. Alloys Compd.
(2017)
X.T. Wang et al.
Preparation of NiSe₂/TiO₂ nanocomposite for photocathodic protection of stainless steel
Mater. Lett.
(2016)
W.X. Sun et al.
3D hierarchical WO₃ grown on TiO₂ nanotube arrays and their photoelectrochemical performance for water splitting
J. Alloys Compd.
(2017)
W.X. Sun et al.
Hierarchical WO₃/TiO₂ nanotube nanocomposites for efficient photocathodic protection of 304 stainless steel under visible light
J. Alloys Compd.
(2018)
D.T. Zhou et al.
In-situ construction of all-solid-state Z-scheme g-C₃N₄/TiO₂ nanotube arrays photocatalyst with enhanced visible-light-induced properties
Sol. Energy Mater. Sol. Cell.
(2016)
Y.X. Zhu et al.
Construction of hybrid Z-scheme Pt/CdS-TNTAs with enhanced visible-light photocatalytic performance
Appl. Catal. B Environ.
(2015)

J. Li et al.

A photoelectrochemical study of CdS modified TiO₂ nanotube arrays as photoanodes for cathodic protection of stainless steel

Thin Solid Films

(2011)

H. Li et al.

Preparation and photocathodic protection performance of CdSe/reduced graphene oxide/TiO₂ composite

Corrosion Sci.

(2015)

Z.Q. Lin et al.

A highly efficient ZnS/CdS@TiO₂ photoelectrode for photogenerated cathodic protection of metals

Electrochim. Acta

(2010)

B. Fan et al.

One-pot hydrothermal synthesis of Ni-doped ZnIn₂S₄ nanostructured film photoelectrodes with enhanced photoelectrochemical performance

Appl. Surf. Sci.

(2016)

S.H. Shen et al.

Insights into photoluminescence property and photocatalytic activity of cubic and rhombohedral ZnIn₂S₄

J. Solid State Chem.

(2011)

Y. Xia et al.

Heterojunction construction between TiO₂ hollowsphere and ZnIn₂S₄ flower for photocatalysis application

Appl. Surf. Sci.

(2017)

F. Spadavecchia et al.

Solar photoactivity of nano-N-TiO₂ from tertiary amine: role of defects and paramagnetic species

Appl. Catal. B Environ.

(2010)

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3D ZnIn2S4 nanosheets/TiO2 nanotubes as photoanodes for photocathodic protection of Q235 CS with high efficiency under visible light

Highlights

Abstract

Introduction

Section snippets

Preparation of ZnIn2S4/TiO2 NTs and Q235 CS electrodes

Crystal structure and morphology

Conclusions

Acknowledgements

Electrochem. Commun.

Chem. Eng. J.

J. Alloys Compd.

Appl. Surf. Sci.

J. Alloys Compd.

Mater. Lett.

J. Alloys Compd.

J. Alloys Compd.

Sol. Energy Mater. Sol. Cell.

Appl. Catal. B Environ.

Thin Solid Films

Corrosion Sci.

Electrochim. Acta

Appl. Surf. Sci.

J. Solid State Chem.

Appl. Surf. Sci.

Appl. Catal. B Environ.

3D ZnIn₂S₄ nanosheets/TiO₂ nanotubes as photoanodes for photocathodic protection of Q235 CS with high efficiency under visible light

Preparation of ZnIn₂S₄/TiO₂ NTs and Q235 CS electrodes