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TiO 2 based nanopowder coatings over stainless steel plates for UV‐C photocatalytic degradation of methylene blue
Author(s) -
Jiao Yongmei,
Basiliko Nathan,
Kovala A. Thomas,
Shepherd Jeffrey,
Shang Helen,
Scott John A.
Publication year - 2020
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23653
Subject(s) - photocatalysis , materials science , anatase , annealing (glass) , methylene blue , chemical engineering , doping , coating , rutile , band gap , visible spectrum , degradation (telecommunications) , metallurgy , composite material , nanotechnology , optoelectronics , catalysis , chemistry , organic chemistry , engineering , telecommunications , computer science
Immobilizing the photocatalyst in a water treatment process design is essential; however, the immobilization method may affect the photoactivity of the photocatalyst. In this work, photocatalyst powders were successfully coated on 316 L stainless steel plates by a novel brush coating method. Three combinations of photocatalyst mixtures (pure TiO 2 anatase, anatase doped with WO 3 , or TiO 2 rutile) were and annealed at different temperatures between 460‐540°C. The ~ 10 μm thick coatings demonstrated full plate coverage and strong adhesion and adequate durability. Surface roughness increased with annealing temperature. The doping and annealing process enabled band gap reduction to the visible light spectrum for all coatings, with the smallest band gap being 2.48 eV (1 eV = 1.6 × 10 −19 J). Subsequent methylene blue degradation tests under UV‐C showed that the coatings annealed in 460°C exhibited the best performance and with the highest degradation rate constant of 5.59 hours −1 .