Fabrication of Mn–ZnO photoanodes for photoelectrochemical water splitting applications

• Published in: Journal of materials science. Materials in electronics 2021-08, Vol.32 (16), p.20946-20954
• Main Authors: Khan, Humaira Rashid, Akram, Bilal, Aamir, Muhammad, Malik, Muhammad Azad, Tahir, Asif Ali, Choudhary, Muhammad Aziz, Akhtar, Javeed
• Format: Article
• Language: English
• Subjects: Aerosols; Characterization and Evaluation of Materials; Chemical vapor deposition; Chemistry and Materials Science; Crystallites; Density; Electrolytes; Energy gap; Glass substrates; Homogeneous structure; Incorporation; Manganese; Materials Science; Morphology; Optical and Electronic Materials; Optical properties; Photoanodes; Photoelectric effect; Photoelectric emission; Semiconductors; Thin films; Water splitting; Zinc oxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06471-8

A photoelectrochemical (PEC) water splitting ability of pure ZnO and manganese-incorporated ZnO thin films fabricated via a simple aerosol-assisted chemical vapour deposition (AACVD) method was compared in Na 2 SO 4 electrolyte solution. Optical properties analysis showed the shifting of optical band gap from 3.02 to 2.76 eV as the molar ratio of Mn varies from 0.02 to 0.15. All the compositions of Zn 1− x Mn x O ( x  = 0.02 to 0.15) show superior photocurrent density compared to pure ZnO-based photoanodes. The activity of Zn 0.85 Mn 0.15 O was found highest with photocurrent density of 3.81 mA/cm 2 . This activity enhancement was due to the shifting of the optical band gap in the visible region with the increase in absorption intensity. Moreover, the activity is further affected by the growth of uniform and homogeneous structures onto the photoanodes. The morphology of the films and size of crystallites change by varying amounts of Mn into the ZnO films. Overall, this work demonstrates that Zn 1− x Mn x O has a significant potential for PEC water splitting with further tailoring of their electronic properties.