Photocatalytic activity of self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition. (13th April 2018)

• Record Type: Journal Article
• Authors: Shi, Pengjun; Li, Xibo; Zhang, Qiuju; Yi, Zao; Luo, Jiangshan
• Is Part Of: Materials research express. Volume 5:Number 4(2018)
• Publication Date: 2018-04-13
• Subjects: TiO2 nano-columns array -- oblique angle deposition -- photocatalytic activity; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aaba57
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: A well-separated and oriented TiO2 nano-columns arrays with porous structure were fabricated by the oblique angle sputter deposition technique and subsequently annealing at 450 °C in Ar/O2 mixed atmosphere. The deposited substrate was firstly modified by a template of self-assembled close-packed arrays of 500 nm-diameter silica (SiO2 ) spheres. Scanning electronic microscopic (SEM) images show that the porous columnar nanostructure is formed as a result of the geometric shadowing effect and surface diffusion of the adatoms in oblique angle deposition (OAD). X-ray diffraction (XRD) measurements reveal that the physically OAD film with annealing treatment are generally mixed phase of rutile and anatase TiO2 polymorphic forms. The morphology induced absorbance and band gap tuning by different substrates was demonstrated by the UV–vis spectroscopy. The well-separated one-dimensional (1D) nano-columns array with specific large porous surface area is beneficial for charge separation in photocatalytic degradation. Compared with compact thin film, such self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition performed an enhanced visible light induced photocatalytic activity by decomposing methyl orange (MO) solution. The well-designed periodic array-structured porous TiO2 films by using modified patterned substrates has been demonstrated significantly increased absorption edge in the UV-visible light region with a narrower optical band gap, which are expected to be favorable for application in photovoltaic, lithium-ion insertion and photocatalytic, etc.