Increased photocorrosion resistance of ZnO foams via transition metal doping. Issue 4 (17th January 2023)

• Record Type: Journal Article
• Authors: Warren, Zachary; Wenk, Jannis; Mattia, Davide
• Is Part Of: RSC advances. Volume 13:Issue 4(2023)
• Page Start: 2438
• Page End: 2450
• Publication Date: 2023-01-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2ra06730g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Practical use of ZnO is hindered by its low resistance to photocorrosion in water, which leads to metal leaching and loss of performance over time. Here we demonstrate how metal doping can significantly increase ZnO's resistance to photocorrosion. Abstract : ZnO is a widely studied photocatalyst, but practical use is hindered by its low resistance to photocorrosion in water, which leads to metal leaching and loss of performance over time. In this work, highly porous and mechanically stable ZnO foams, called MolFoams, were doped by adding 1% or 2% Co, Ni or Cu salts to the starting Zn salt, followed by air insufflation during a sol–gel rection and sintering. The resulting doped foams showed a major increase in stability, with a 60–85% reduction in Zn 2+ leaching after irradiation, albeit with a reduction in photocatalytic activity. A systematic analysis using XRD, Raman, XPS and XANES allowed for the identification of dopant species in the foams revealing the presence of Co3 O4, NiO and Cu2 O within the ZnO lattice with doping leading to a reduced band gap and significant increases in the resistance to photocorrosion of ZnO while identifying the cause of the reduction in photocatalytic activity to be shifting of the band edge positions. These results provide a pathway to significantly reduce the photocorrosion of ZnO in water, with further work required to maintain the photocatalytic activity of undoped ZnO.