INTRODUCTION

The breakdown of environmental and wastewater contamination brought on by textile effluents has generated a great deal of academic attention during the past two decades. Vanadium pentoxide (V₂O₅) is an excellent semiconductor with a low bandgap energy (2.2 eV) and has been researched as a visible light active catalyst for the photo degradation of organic contaminants. This is one of the many oxide based semiconductors. Additionally, V₂O₅ has commercial uses in optoelectronic devices, gas sensors, and lithium-ion batteries. However, the efficient breakdown of pollutants is reduced by the quick recombination of photo generated electron-hole pairs in the photocatalytic process[1-3]. As a result, numerous approaches have been investigated by the scientific community to address this issue. The coupling of two semiconductors is one of the crucial methods. Coupled semiconductor photo catalysts are used. Among several metal oxides, ZnO has gained much attention in material science, physics, chemistry, and biochemistry due to its high stability, transparency, high exciton binding energy (60 meV), high piezoelectric constant, and wide energy band gap .The wide band gap 3.37 eV and fast e−/h + recombination restrict its application as a dynamic photo catalyst . This discrepancy can overcome by combining it with the other metal oxides [4-8]. Remarkably, vanadium oxide (V₂O₅), an n-type semiconductor. ZnO is a Wide bandgap (3.2 eV) n-type semiconducting material is well known for its catalytic uses in gas sensors, dye-sensitive solar cells, photo-catalysts, and other devices[9-13]. It also absorbs a larger portion of the solar spectrum There aren’t many reports on V₂O₅ and ZnO semiconductor connection. In this paper, we describe the hydrothermal method for the fabrication of nanoscale ZnO/ V₂O₅ composites as show in Figure 1. Different approaches were used to examine the produced composite’s structural and optical qualities. Additionally, the photodegradation of maxillion blue (GRL) was used to gauge the photocatalytic activity of a nanocomposite, and the results are explained in depth [14-16].

MATERIALS AND METHODS

Materials

Ammonium  metavandates  (NH₄VO₃), Zinc acetate, Oxalic acid was purchased from (Germany, Sigma-Aldrich), and Aqueous ammonia(25%) were used, Maxillion Blue (GRL) dye was prepared. A stander solution was preparing via 0.1g in 1000ml to obtained 100 mg/ L as an appropriate amount of GRL dye double distilled water.

Preparation Vanadium Oxide Pentahydrate of Zinc Oxide Composite ZnO/V₂O₅

ZnO/V₂O₅ nanoparticles were prepared by thermal hydrolysis of ammonium metavandates (NH₄VO₃), and these experiment was carried out in a 150 mL Teflon cup enclosed in a stainless steel autoclave (Berghof, DAB-3.( 

In all experiments, 25 mL of ammonium metavandates aqueous solution (0.5 gm NH₄VO₃, 25 ml water), in the presence 75ml of an aqueous Zinc acetate solution (20.6 gm Zinc acetate, 75 ml water), were mixed, Then this solution was mixed very well for further 60 minutes. followed by the addition 6.3 gm of Oxalic acid and 65ml of Aqueous ammonia (25%) to the mixture, then this solution was mixed very well for further 120 minutes, the outcome was then poured into the teflon cup. The Teflon cup was then sealed within the autoclave, which was then shut and placed inside an electric furnace maintained at 160 °C for 24 hr.  The autoclave was finally cooled to room temperature, and the resulting powder was separated by centrifuge at 6000 rpm speed for several times (at least three times), washed with distal water at least for four times , and dried overnight in an oven at 60°C  as appear in Fig. 2.  

Photocatalytic experiments

Stock solutions of 1g of GRL dye   (1000 mL) were prepared,  .The different concentrations of dye (10-50) mg L^-1 in 200 mL solution GRL dye  , and  different  Weight (0.1-0.6 g) of  ZnO/ V₂O₅ nanocomposite was studied at a concentration of 10 mg L^-1(in 200 mL  GRL dye ) and intensity of light is 2 mw/cm2, and  effect of different light intensity of  dye  by nanocomposite was studied at  smeller optimum condition . All experiments were carried out in a photo- reaction vessel, an adsorption was performed for 10 min. before the photocatalytic process, ads the beaker was put under the UV-visible lamp for 1 h, using UV Visible spectrophotometer 1650 spectrophotometer, Japan) at 590 nm. experimental tests were performed, and calculate the amount of absorbance before photo catalysis and after photo catalysis for 1 hr by use centrifuge at 12000 r/min for 10 min . The photo degradation efficiency was calculated via  eq. (1).

Co: is the initial concentration of GRL and Ct: is concentration of GRL after testing for a period of time (t).

RESULT AND DISCUSSION

X-Ray Diffraction Spectroscopy (XRD)

Spectroscopy via X-Ray Diffraction (XRD) The phase stability and phase transition of the ready catalysts, V₂O₅, were investigated using XRD. Table 1 displays the outcomes of employing the full width at half maximum (fwhm), and the Scherrer equation (as given in eq. 2).

Based on the peak width (B), one may calculate the particle size (P), which yields a shape factor (k) of 0.9, a wavelength of the x-ray source of 0.1541 nm, and a B value for the whole peak width at half maximum corrected for instrumental broadening. The XRD pattern of synthesized catalyst is shown in Fig. 3. Two types of phases were detected in Fig. 3. One type of phase is well indexed to V₂O₅ with an orthorhombic structure. The other type of phase is known to exist in ZnO’s hexagonal structure. This XRD pattern revealed no further possible impurities, such as VO₃ and V2O₃, indicating that the final product solely contained the distinct diffraction peaks of V₂O₅ and ZnO [17].

Field Emission Scans Electron Microscopy (FE-SEM)

Fig. 4 indicates that better dispersion of the FE-SEM is with exact great agglomeration. From XRD crystalline size result and FESEM micrographs, it could be concluded that all ZnO/V₂O₅ prepared have small nano-particles crystallize. However, SEM measurements proof a full agreement with the crystal size estimated by XRD measurements. ZnO/V₂O₅ shows the agglomeration phase this attributed to the low crystalinity, furthermore also results show sample ZnO/V₂O₅ is homogenous in shape and size. The aggregation of particles (or formation of larger particles) should have been originated from the large specific surface area and high surface energy of ZnO/V₂O₅ nano-particles. Thus, due to the large specific surface area and high surface energy, ZnO/V₂O₅ nanoparticles aggregate severely. The study of FE-SEM micrographs reveals a less number of pores with smaller lump size, so for behavior of particles to produce nano rode shapes instead of spindle particles[18-20].

EDS data indicated vanadium connected with Zinc and oxygen in distinct particles, (Fig. 5). The XRD analysis identified the nanocomposite elements. As determined by EDS, the predominant elements samples were vanadium, Zinc, oxygen, and carbon. Vanadium was primarily associated with Zinc [21, 22].

Effect of mass dosage

Effect of amounts (0. 1, 0.2, 0.4, 0.6) gm of ZnO/ V₂O₅ nanocomposite on the cracking and degradation of (GRL) dye, photocatalytic degradation in the solution GRL dye concentration 10 mg/L, reaction at 25°C, time is 1h. First order experimental data were analyzed as shown in Fig . 6. 

The influence of adsorbent dose on the removal of 10 mg/L GRL dye as appear in Fig. 6. The increasing of weight of ZnO/ V₂O₅ composite about (0.1 - 0.2)gm, the PDE%  improved of [48.6 - 84.08 %] after 1houre [23]. 

Effect of concentration of GRL dye 

Several dye concentrations (10-50 mg/L), were carefully chosen to study the influence of initial GRL dye concentration on to ZnO/V₂O₅ composite. The quantities of GRL adsorbed at solution pH 6, weight of nanocomposite  about 0.6 g appear in Fig. 7. GRL dye solution plays a pivotal role in estimate rate of degradation, also the time dependence of photocatalytic degradation of GRL under several concentrations. The experimental result could be analyzed to assume first order kinetic appear in Fig. 7. The increasing of GRL dye concentration about 5 – 20 mg/L, the removal percentage improved of [59.52 - 34.1%] after 1houre time of adsorption[23-25].

Effect of light intensity (L.I)

The effect of light intensity (0.8- 2.6) mw/cm², was observed via change the distance among light source and exposed surface of the material. photo degradation of GRL dye  via the influence of L.I was studied in ZnO/V₂O₅ composite 0.4 g,  concentration of GRL dye 10 mg/L. All reactions were discovered to continue following the first-order kinetics depicted in Fig. 8. As more radiation is accessible to excite the catalyst and, as a result, more charge carriers are created, the rate of photocatalytic degradation and PDE% increased with increasing U.V intensity light[3, 14, 26].

CONCLUSION

The hydrothermal method was used to create the ZnO/ V₂O₅ nanocomposite. XRD examination revealed the ZnO/ V₂O₅ nanocomposite production. The creation of nano-rods with some spherically shaped particles is seen in the FE-SEM image, while vanadium, zinc, and oxygen are detected in the EDXS study.  In the presence of low concentrations and increase weight composite , the photocatalytic degradation of GRL dye was most effective. With the weight of ZnO/ V₂O₅ nanocomposite rising by (0.1 - 0.2)g, PDE% increased by [48.6 - 84.08%] after one hour.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interests regarding the publication of this manuscript.