Preparation of graphene film decorated TiO2 nano-tube array photoelectrode and its enhanced visible light photocatalytic mechanism

• Published in: Carbon (New York) Vol. 66; pp. 450 - 458
• Main Authors: Cheng, Xiuwen, Liu, Huiling, Chen, Qinghua, Li, Junjing, Wang, Pu
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2014; Elsevier
• Subjects: absorption; Arrays; Chemistry; Cross-disciplinary physics: materials science; rheology; Degradation; electric current; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; General and physical chemistry; Graphene; hydroxyl radicals; irradiation; light intensity; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanotubes; NTA; Photocatalysis; Photochemistry; photolysis; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Physics; Polycarbonates; Raman spectroscopy; Specific materials; Titanium dioxide; ultraviolet radiation; X-ray diffraction; X-ray photoelectron spectroscopy; Films; Graphene; Photocatalysis; Preparation; Transition element compounds; Nanotubes; Visible radiation; Binary compounds; Titanium oxide; Arrays; Mechanism; Photoelectrode
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2013.09.021

Graphene film decorated TiO2 nano-tube array (GF/TiO2 NTA) photoelectrodes were prepared through anodization, followed by electrodeposition strategy. Morphologies and structures of the resulting GF/TiO2 NTA samples were characterized by scanning electrons microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the optical and photoelectrochemical properties were investigated through UV–visible light diffuse reflection spectroscopy, photocurrent response and Mott–Schottky analysis. Furthermore, the photodecomposition performances were investigated through yield of hydroxyl radicals and photocatalytic (PC) degradation of methyl blue (MB) under visible light irradiation. It was found that GF/TiO2 NTA photoelectrode exhibited intense light absorption both in UV light and visible region, higher transient photoinduced current of 0.107mAcm−2 and charge carrier concentration of 0.84×1019cm−3, as well as effective PC performance of 65.9% for the degradation of MB. Furthermore, contribution of several reactive species to the PC efficiency of GF/TiO2 NTA photoelectrode was distinguished. Moreover, the enhanced visible light PC mechanism was proposed and confirmed in detail.