Direct Z-scheme MgIn2S4/TiO2heterojunction for enhanced photocathodic protection of metals under visible light

Hong Li; Xingqiang Cui; Weizhe Song; Zhanyuan Yang; Yanhui Li; Pengfei Zhang; Zongmin Zheng; Yuqi Wang; Junru Li; Fubin Ma

doi:10.1088/1361-6528/ac493c

Direct Z-scheme MgIn₂S₄/TiO₂heterojunction for enhanced photocathodic protection of metals under visible light

Nanotechnology. 2022 Jan 28;33(16). doi: 10.1088/1361-6528/ac493c.

Authors

Hong Li^{1

2}, Xingqiang Cui^{1

2}, Weizhe Song^{1

2}, Zhanyuan Yang^{1

2}, Yanhui Li^{1

2}, Pengfei Zhang¹, Zongmin Zheng^{2

3}, Yuqi Wang^{1

2}, Junru Li¹, Fubin Ma^{4

5}

Affiliations

¹ College of Mechanical and Electrical Engineering, Qingdao University, No. 308 Ningxia Road, Qingdao, 266071, People's Republic of China.
² State Key Laboratory of Bio-fibers and Eco-textiles, Qingdao University, No. 308 Ningxia Road, Qingdao, 266071, People's Republic of China.
³ National Engineering Research Center for Intelligent Electrical Vehicle Power System, Qingdao University, No. 308 Ningxia Road, Qingdao, 266071, People's Republic of China.
⁴ Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China.
⁵ Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, People's Republic of China.

PMID: 34996059
DOI: 10.1088/1361-6528/ac493c

Abstract

To improve the photocathodic protection performance of traditional TiO₂photoanodes for metals, constructing a Z-scheme heterojunction is one of the most promising and creative strategies. Herein, we fabricated a novel Z-scheme MgIn₂S₄nanosheets/TiO₂nanotube nanocomposite through anodization and hydrothermal method. The optimized Z-scheme MgIn₂S₄/TiO₂nanocomposites exhibited stronger visible light absorption, higher separation efficiency of photoelectrons and photocathodic protection performances in comparison to pure TiO₂. The theoretical analysis and experimental results show that the Z-scheme heterojunction and oxygen vacancies jointly improved the separation efficiency of photogenerated electron-hole pairs and visible light absorption capacity, thereby improving the photoelectric conversion performance of the MgIn₂S₄/TiO₂nanocomposites. Furthermore, the influence of the precursor solution concentration on the photocathodic protection performances of the composites was investigated. As a result, when the concentration of magnesium source in the precursor solution was 0.06 mmol, the prepared MgIn₂S₄/TiO₂-0.06 displayed the best photocathodic protection performance. In addition, the hydroxyl radicals (·OH) generated in the electron spin resonance (ESR) experiment verified the Z-scheme heterojunction mechanism of the MgIn₂S₄/TiO₂composite, and also demonstrated the excellent redox performance of the composite. This work provides valuable reference for the construction of high-performance Z-scheme heterojunctions for photocathode protection of metals.

Keywords: ESR; MgIn2S4; TiO2; Z-scheme; photocathodic protection.