Photoelectrochemical Investigation of TiO2-Graphene Nanocomposites

Abstract

In this study TiO2 was photosensitized by graphene to improving the visible spectral absorption and photoactivity under visible light irradiation. TiO2 was added to different content of graphene oxide and with hydrothermal method and 1, 3 and 5 percentage of graphene-TiO2 composite (TG) was synthesized. The prepared samples were characterized by XRD, Raman, DRS, and SEM.Photoelectrochemical experiments exhibited that the photocurrent response of three percentages of TG nanocomposite was higher than others.

Photocatalytic Graphene-TiO2 Thin Films Fabricated by Low-Temperature Ultrasonic Vibration-Assisted Spin and Spray Coating in a Sol-Gel Process

“…Ti-O vibration is identified at 670 cm −1 . The left shoulder absorption band at 807 cm −1 and the minor peaks around 2800-3100 cm −1 are consistent with Ti-O-C binding, showing the chemisorption between TS and GD solutions [15,28]. The same peaks (2800-3100 cm −1 ) may be attributed to metal (in this case, Ti) and methyl groups (Ti-CH x ), as well [29].…”

“…The other peak at 45.4 • is due to 211 anatase plane and appears when the film is deposited from the solution with TS:GD of 1:4 and annealed at 150 • C [18]. The reflection peak at 56.6 • is assigned to 211 anatase and 105 rutile planes [3,13,15]. These signals are weak in the composite films with low TiO 2 content, but are quite strong in the TiO 2 -rich film annealed at 150 • C. Another signature of TiO 2 , 200 anatase plane at 48 • only appears in the rich-TiO 2 film annealed at 150 • C. Therefore, a TiO 2 -rich composite film annealed at 150 • C shows ideal transformation of titanium precursors to crystalline TiO 2 .…”

“…In addition, graphene-TiO 2 hybrid compound, in the form of powders or thin films, enables an extended light harvesting capability, owing to Ti-O-C bonding. Also, graphene-TiO 2 interfaces provide effective charge transfer junctions, which help the injection of electrons from TiO 2 to graphene sheets leading to prolonged recombination [7,[13][14][15][16]. Beside coordination with inorganic materials, graphene provides a strong chemical affinity with organic materials, in particular with the organic dyes [17].…”

“…In a study conducted by Cheng et al [14], graphene-TiO 2 composite was synthesized by solvothermal reaction, using various graphene to TiO 2 ratios. Rahimi et al [15] studied the role of graphene content on light absorption and photoactivity of graphene-TiO 2 blend made by solvothermal method. Xia et al [3] used chemisorption assembly in which titanium (IV) isopropoxide (TIP) was added to functionalized graphene oxide suspension, followed by an intensive thermal treatment.…”

Compositing Two-Dimensional Materials with TiO2 for Photocatalysis

“…The common procedure for ex-situ hybridization is to mix GO and modified TiO 2 with physical process such as ultrasound sonication and heat treatments. Rahmatollah et al [62] reported a facile one-step solvothermal method to synthesize the TiO 2 -graphene composite sheets by dissolving different mass ratios of GO and TiO 2 nanoparticles in anhydrous ethanol solution.…”