Carbon quantum dots/Ag sensitized TiO2 nanotube film for applications in photocathodic protection

• Published in: Journal of alloys and compounds Vol. 797; pp. 912 - 921
• Main Authors: Guan, Zi-Chao, Jin, Piao, Liu, Qing, Wang, Xia, Chen, Li-Fang, Xu, Hui, Song, Guang-Ling, Du, Rong-Gui
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.08.2019; Elsevier BV
• Subjects: Ag nanoparticles; Carbon; Carbon quantum dots; Corrosion potential; Corrosion prevention; Electromagnetic absorption; Hydrothermal treatment; Light irradiation; Nanoparticles; Nanotubes; Photocathodic protection; Photoelectric effect; Photoelectric emission; Photographic film; Protective coatings; Pulse electrodeposition; Quantum dots; Silver; Sodium sulfate; Stainless steels; Substrates; TiO2 nanotubes; Titanium; Titanium dioxide; White light; Photocathodic protection; TiO2 nanotubes; Ag nanoparticles; Carbon quantum dots; Pulse electrodeposition
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.05.199

In order to obtain a TiO2 composite film with improved photoelectrochemical properties, a TiO2 nanotube array (NTA) film was constructed on a Ti substrate via anodization, then Ag nanoparticles (NPs) and carbon quantum dots (CQDs) were successively deposited on the TiO2 NTA film by pulse current deposition and hydrothermal treatment, respectively. After the sensitization by CQDs and Ag NPs, the light absorption of the TiO2 composite film was extended to the visible region. Under white light irradiation, the photocurrent density of the composite film in a 0.5 M Na2SO4 solution reached 110 μA cm−2, much higher than that (60 μA cm−2) of the single TiO2 film. The CQDs/Ag/TiO2 composite film as a photoanode showed an improved photocathodic protection effect, which made the potential of the coupled 403 stainless steel (403SS) in the 0.5 M NaCl solution drop by 400 mV relative to its corrosion potential. [Display omitted] •A carbon quantum dot and Ag nanoparticle modified TiO2 nanotube film was fabricated.•Photoresponse of the CQDs/Ag/TiO2 film was extended into the visible light region.•The CQDs/Ag/TiO2 composite film showed an enhanced photoelectrochemical performance.•The CQDs/Ag/TiO2 film provided effective photocathodic protection for 403SS.