Photodegradation of lauth’s violet dye using GO-Fe3O4-TiO2 nanocomposite under solar light

TFGO nanocomposite was synthesized from limited amounts of Titanium dioxide nanoparticles and Iron oxide nanoparticles as well as Graphene oxide nanosheets, by a situ method preparation. The producting materials were identify by (FTIR) and (AFM). The photocatalysis activity of TFGO nanocomposite was investigated by applying it in advanced oxidation processes (AOP) to degradation of Lauth’s violet or Thionine acetate (LV) dye under solar light. The photodegradation efficiency of LV dye could be gained 98% at existance of TFGO nanocomposite as photocatalyst within 320 min. Photocatalytic processes experiments were happen at different effects like temperatures and existence of light.


1.Introduction
Organic pollutants are widely found in the effluents from the different industries like petrochemical ,dyestuffm, leather, cosmetics, papers, food and pesticide industries [1], which are caused clear hazards and serious health problems [2]. Recently, many studies have reported the efficient elimination of these organic contaminants using classical methods of removing these pollutants such as coagulation [3], adsorption [4,5], flocculation, oxidation [6], membrane separation [7,8], as well as photocatalysts [9]. Photocatalysis is an advanced oxidation (AOP) process which is applied for degradation of diverse pollutant under solar light. So, it is more desired to prepare photocatalysts that can worked efficaciency under natural light.
Among several photocatalysts, titanium dioxide (TiO2) is a semiconductor, and it is the particularly suitable material for common applications such as energy storage, photocatalysis and wide range of environmental applications [10].TiO2 is an environmental-friendly material, non-toxic, stable in aqueous solutions, relatively inexpensive, strong oxidizing power, having high chemical inertness, high thermal stability and photostability [11,12].
However the widly energy gap, the slow transfer rate of electrons to oxygen and the high recombination rate of the generated charge carriers, that lead to limited the efficiency of TiO2 as photocatalyst [13].
The efficiency of TiO2 as photocatalyst can be often enhanced by coupling TiO2 nanparticles with any other semiconductor and merged with the materials which accepting the electrons, like carbon nanostructures [14].
In this research, (TFGO) nanocomposite (consist of different amounts of GO nanosheets, F3O4, and TiO 2 nanoparticles) was prepared by using a self-assembly way at normal conditions. The efficiency of the TFGO composite for the Lauth's violet LV dye degradation is studied and the related photo-

Fabrication of TFGO nanocomposite
The chemicals which used in our study from Sigma Aldrich and without any purification. The anatase TiO2 nanoparticles were purchased from Hongwu International Group Ltd-China , and there size are about 30nm-50nm. The graphine oxide (GO) nanosheets were prepared by using a modified Hummers way is illustrated in Scheme 1 [15]. and the FGO nanocomposite was obtained by selfassembly way according to the a literature [9]. The synthetic procedure for the FGO nanocomposite nanocomposite is illustrated in Scheme 2, while TFGO nanocomposite which consist of limited amounts of FGO nanocomposite and titanium dioxide nanoparticles.

. Test of Photocatalysis Efficiency
The photocatalytic Efficiency of the prepared catalyst (TFGO nanocomposite) were evaluated with sun light as UV irriadiation source by photocatalytic degradation in LV aqueous solution. During all experiments of BG dye degradation, the temperature was (35C). 8 samples contain (0.05g) of catalysts (TFGO nanocomposite) was added to the 50 ml of (10 ppm) LV solution, and they shaking at 100 cycle min -1 in the dark for 70 min to reach the adsorption-desorption equilibrium (shown in Fig. S2) before the catalytic activity test. Subsequently, the heterogeneous Photocatalytic process was started when the samples was putted under sun radiation and of catalysts (TFGO nanocomposite) was added. Then , the samples were withdrawn at limited time intervals and the Photocatalysis were removed by the magnetic separation, and the residual LV dye concentration was determined by using Visible spectroscopy at 599 nm [9].

1 Characterization
The atomic force microscope (AFM) analysis measure the surface structure with high accuracy up to parts of the nanometer in addition to measuring the granular size [17][18][19]. AFM analysis and the particle size distribution of (GO nanosheets  It is also possible to observe (AFM) examination of the iron oxide nanoparticles that were subsequently deposited on the surface of the graphene oxide as the maximum height of is (7.86 nm) as shown in Figure (

photo degradation efficiency
The photo degradation of LV dye in existance of TFGO nanocomposite as photocatalyst agents was studied under solar light energy. The residue amount of LV dye in the reaction blend was calculated by using spectrophotometer. The results gained for the degradation of LV dye be seen in Figures 8, 9. The eminent degradation of LV dye was in 320 min study in the existance of TFGO The photodegradation reaction of LV dye in existance of TFGO nanocomposite as photocatalyst was studied at presence of sun light or at the dark. From the results which exhibit in Figure 24

b. Effect of Temperatures
The photodegradation reaction of LV dye solution in existance of TFGO nanocomposite as photocatalyst was also carried out under varying temperature conditions from (298 to 318k), ( Figure  9). The percentage of Photodegradation efficiency was found to very low at 298k for TFGO nanocomposite, and then increases at 308k,and then at 318 k, this is due to the increase in the speed of the photodegradation reaction with increasing temperatures.

Conclusion:
The purpose of this article was to describe that, prepared FGO and TFGO nanocomposite from limited amount of GO nanosheets, F3O4 nanoparticles, TiO2 nanoparticles . The prepared materials and components were characterized by using many advises like (FTIR) and (AFM). The performance of prepared materials and components as photocatalyst was investigated by applying them in advanced oxidation processes (AOP) to degradation of BG dye under solar light. The photodegradation efficiency of LV dye could be gained 98% at existance of TFGO nanocomposite as photocatalyst within 320 min. Photocatalytic processes experiments were happen at different effects like Photocatalysis, temperatures and existence ofsun light.