Accelerated anode and cathode reaction due to direct electron uptake and consumption by manganese dioxide and titanium dioxide composite cathode in degradation of iron composite

Cijun Shuai; Shiwei Zhong; Yang Shuai; Wenjing Yang; Shuping Peng; Chongxian He

doi:10.1016/j.jcis.2022.11.055

Accelerated anode and cathode reaction due to direct electron uptake and consumption by manganese dioxide and titanium dioxide composite cathode in degradation of iron composite

J Colloid Interface Sci. 2023 Feb 15;632(Pt A):95-107. doi: 10.1016/j.jcis.2022.11.055. Epub 2022 Nov 15.

Authors

Cijun Shuai¹, Shiwei Zhong², Yang Shuai³, Wenjing Yang², Shuping Peng⁴, Chongxian He⁵

Affiliations

¹ Institute of Additive Manufacturing, Jiangxi University of Science and Technology, Nanchang 330013, China; State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
² Institute of Additive Manufacturing, Jiangxi University of Science and Technology, Nanchang 330013, China.
³ College of Life Science and Technology, Huazhong University of Science and Technology, 430074, China.
⁴ The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Xiangya Hospital, Central South University, 410078, China; NHC Key Laboratory of Carcinogenesis of Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Cancer Research Institute, School of Basic Medical Science, Central South University, 410013, China; School of Energy and Machinery Engineering, Jiangxi University of Science and Technology, Nanchang 330013, China. Electronic address: shuping@csu.edu.cn.
⁵ Institute of Additive Manufacturing, Jiangxi University of Science and Technology, Nanchang 330013, China. Electronic address: hechongxian@csu.edu.cn.

PMID: 36410298
DOI: 10.1016/j.jcis.2022.11.055

Abstract

The movement towards the clinical application of iron (Fe) has been hindered by the slow degradation rate in physiological environments. Herein, manganese dioxide (MnO₂) particles were compounded with titanium dioxide (TiO₂) particles by mechanical ball milling, and then the mixed powders were incorporated into Fe and fabricated into an implant using selective laser melting. On the one hand, MnO₂ had a higher work function (5.21 eV) than Fe (4.48 eV), which inclined electrons to transfer from Fe to MnO₂ to accelerate the anode reaction. On the other hand, MnO₂ catalysed the oxygen reduction reaction (ORR) through a four-step proton-electron-coupled reaction, which caused more oxygen to flow into the sample to improve the cathode performance. Besides, anatase TiO₂ with high conductivity was compounded with MnO₂ to construct a composite cathode, which facilitated electron transport from the cathode to the electrolyte, further consuming electrons and promoting cathode reaction. Results showed that Fe-MnO₂-TiO₂ had a high limiting current density of 5.32 mA·cm^-2 and a large half-wave potential of -767.4 mV, indicating an enhanced ORR activity. More significantly, Fe-MnO₂-TiO₂ had a higher average electron transfer number (2.9) than Fe-MnO₂ (2.5), demonstrating a faster electronic consumption reaction and higher cathode performance. In addition, the Fe-MnO₂-TiO₂ also exhibited fast instantaneous and long-term degradation rates (0.33 ± 0.03 and 0.19 ± 0.02 mm/year), suggesting a high anode dissolution rate. In conclusion, introducing the cathode with high work function and ORR activity provides novel pathways for accelerating the degradation rate of Fe-based implants.

Keywords: Electron consumption; Electron uptake; ORR activity; Work function.

MeSH terms

Electrodes
Electrons
Iron
Manganese Compounds*
Oxides*
Oxygen

Substances

manganese dioxide
Manganese Compounds
titanium dioxide
Oxides
Iron
Oxygen