Graphene facilitated visible light photodegradation of methylene blue over titanium dioxide photocatalysts

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 214; no. 1; pp. 298 - 303
• Main Authors: Liu, Shizhen, Sun, Hongqi, Liu, Shaomin, Wang, Shaobin
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01-01-2013; Elsevier
• Subjects: absorption; Applied sciences; bleaching; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; Fourier transform infrared spectroscopy; General and physical chemistry; Graphene; hydrolysis; Methylene blue; Photocatalysis; photolysis; physicochemical properties; Reactors; reflectance; scanning electron microscopy; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; thermal analysis; TiO2; titanium; titanium dioxide; Visible light; X-ray diffraction; Visible light; Graphene; Photocatalysis; TiO2; Methylene blue; Scanning electron microscopy; Thermogravimetry; Differential thermal analysis; X ray diffraction; Precursor; Composite material; Hydrolysis; Ultraviolet radiation; Bleaching; Visible radiation; Light absorption; Fourier-transformed infrared spectrometry; TiO; Titanium oxide; Catalyst; Physicochemical properties; Photochemical degradation; Reflectance
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2012.10.058

[Display omitted]
► Graphene–titania composites (G–TiO2) were synthesized by a sol–gel method. ► G–TiO2 catalysts showed high efficiency in degradation of methylene blue under visible light. ► In situ prepared G–TiO2 presented higher activity than that of G–TiO2(P25). ► The mechanism of graphene in the enhanced visible light photocatalytic activity was proposed.
Several graphene–titania composites (G–TiO2) were synthesized by a sol–gel method using titanium isopropoxide (or P25) as Ti-precursors and reduced graphene oxide (RGO). The structural, morphological, and physicochemical properties of the samples were thoroughly investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), UV–vis diffuse reflectance (UV–vis DRS), and thermogravimetric-differential thermal analysis (TG-DTA). A significant increase in light absorption to visible light was observed by G–TiO2 compared with that of naked TiO2. The photocatalytic activity of G–TiO2 in methylene blue bleaching under visible light (>430nm) is much enhanced. G–TiO2 synthesized from titanium isopropoxide hydrolysis presented higher activity than that of G–TiO2(P25). Contribution of graphene on the enhancement of visible-light photocatalytic activity of the composite was discussed.