Photoactivity of Reducing Graphene Oxide and Titanium Dioxide Composite for Cinnamic Acid Degradation

Abstract

Reducing graphene dioxide (rGO) and titanium dioxide (TiO 2) composites with various rGO/TiO 2 ratios were prepared by hydrothermal method, in which rGO was synthesized from graphene powder according to modified Hummers method using microwave. Physico-chemical characteristics of the samples were investigated by the methods of N 2 adsorption-desorption measurements, X-ray diffraction, Raman, Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). rGO-TiO 2 (1:25) catalyst had smaller particle size and higher surface area than whose of pure TiO 2. Moreover, this modification also extended the region of photon absorption of TiO 2 towards the visible range of 397437 nm. The catalytic activity was investigated by photodegradation of cinnamic acid (CA) solution, which have been shown higher activity than that of the pure TiO 2 catalyst. The optimum conditions in this study for the degradation of CA were determined as follows: the ratio rGO/TiO 2 of 1:25, catalyst concentration of 0.75 g•L ¹1 , oxygen supply of 0.5 L•min ¹1 , initial pH solution of 3.8 and reaction temperature of 25°C. In this condition, cinnamic acid conversion in the solution reached approximately 90% after 60 minute reaction.

Photocatalytic Degradation of Methylene Blue (MB) and Methyl Orange (MO) by the Highly Oxidative Properties of SnO₂–Sb₂O₃ Particles

“…These electrons oxidize organic pollutants 15,16) by producing free hydroxyl radicals (•OH) at higher concentration and faster by using UV light. 17) Photocatalyst materials have been used for environmental treatment 18,19) and, over recent decades, several inorganic semiconductors have been studied due to their high oxidative performance without requiring chemicals or high temperatures. 20) They have been used in photovoltaic and photodegradation of organic pollutants in air and water.…”

UV and Visible light photodegradation of methylene blue with graphene decorated titanium dioxide

“…However, for the visible range of the spectrum, TiO 2 does not have photocatalytic activity due to its wide bandgap (3.2 eV in case of anatase) [5,6]. In order to activate photodegradation in the visible range, which would make this process cheaper by using solar light, TiO 2 can be combined with different materials to produce ternary compounds, doping [1,[6][7][8][9][10], nitriding [11], decorating [2] or composites fabrication [7]. The synergetic activity of the external element or compound and the TiO 2 matrix enhances visible light absorption and thus photocatalysis can be produced.…”

Recent Progress in Nanostructured Functional Materials and Their Applications

“…The sixth paper by Nguyen et al showed photoactivity of reducing graphene oxide and titanium dioxide composite for cinnamic acid degradation. 195) In summary, recent trends in nanostructured functional materials and their applications were introduced in this paper by the survey of the special issues related to the international symposia that we organized between 2013 and 2017, which are summarized on Table 1. This field covers a wide area of the materials science, then there are many papers not included in this paper.…”