Synthesis and Characterization of TiO2-(MoO3)/Al2O3 Nanocomposite Using Hydrothermal Method for Environmental Application

Document Type : Research Paper

Authors

1 Department of Chemistry, College of Science, University of Misan, Maysan, 62001, Iraq

2 Department of Chemistry, College of Science, University of Misan, Maysan 62001, Iraq

3 College of Medicine, University of Warith Al-Anbiyaa, Karbala 56001, Iraq

Abstract

In the current research, a hydrothermal synthesis was used to create a nanocomposite of titanium dioxide (TiO2), aluminum oxide (Al2O3), and molybdenum trioxide (MoO3) for use in possible environmental applications. With the assistance of calcination at temperatures of 400 and 800 degrees Celsius, direct hydrothermal synthesis of TiO2-Al2O3/MoO3 powder was effectively accomplished in the presence of ethanol at low pH values at 70 degrees Celsius. The zeta potential and dynamic light scattering techniques, together with scanning electron microscopy (SEM), were utilized in order to evaluate the physicochemical features of the nanoparticles (DLS). Additionally, energy dispersive x-ray (EDX) was utilized in order to do an element distribution analysis on the nanocomposite that was manufactured. According to the findings, a TiO2-Al2O3/MoO3 nanocomposite with an average crystal size of 36.1 nm was successfully manufactured. According to the findings, the new features of this nanocomposite have the potential to be utilized in the development of future environmental applications.

Keywords


INTRODUCTION 
Nanoparticles are used in many aspects of human existence, including in medical, industrial, and environmental applications because of their tunable physicochemical properties resulting from their ultrafine size and high surface area [1-5]. Numerous applications, including drug delivery, tissue engineering, biosensing, nanomedicine, photocatalysis, and electrochemical sensors, make extensive use of nanoparticles [5-10]. Nanoparticles are produced using a variety of techniques, including laser ablation, chemical coprecipitation, sonochemistry, sol-gel, and hydrothermal methods [10-15], the hydrothermal technique is the most effective way to produce nanoparticles of the methods mentioned. This process doesn’t require calcination; it merely uses heat and water as a solvent. The appropriate alignment of crystals and the requirement for their growth at high temperatures and pressures are additional advantages of this technology. Typically, a pressure of less than 25 MPa and a temperature of less than 300 °C are needed for a hydrothermal reaction [16]. Nano-adsorbents for treating wastewater have recently received a lot of attention due to their large surface areas and flexibility in surface modification [17]. TiO2 and other photocatalyst nano-composites have undergone extensive research as traditional photocatalysts in several sectors over the past few decades [18]. Wahyuono, Ruri, et al. also found that TiO2 mixed (WO3) nanocomposite photocatalyst was a powerful adsorbent for methylene blue in an aqueous media. [19]. Numerous investigations have demonstrated that connecting or doping other oxides can improve the performance activity of adsorption. Hanh, Nguyen Thi, et al. [20], for instance, were successful in synthesizing Co3O4/N, S-TiO2 nanoparticles to improve the properties for using accelerated degradation of Direct Blue under visual irradiation. 
Managing environmental quality will be of utmost importance in the near future. In fact, as a result of environmental pollution and/or shortage, regulatory systems would tighten in order to decrease the impact of waste pollutants on the environment and to allow for the recycling of the environment. The standards for tap water quality also need to be adjusted to account for the recently identified contaminants that are being found in rivers or soil. These commitments won’t be met until new, efficient, and effective water treatment technologies are developed. Nanomaterials are advancing the study of more effective oxidation processes [21]. Alternative operating procedures like photo-active nanoparticles, which influence the oxidation of pollutants found in industrial and wastewater effluents and work through the hydroxyl radical to influence the degradation of organic species, have drawn a lot of interest as alternative treatment methods (OH) [22,23]. Strong oxidizing agents and highly reactive hydroxyl radicals with one free electron pair act as the main catalyst for the breakdown of a variety of organic pollutants, such as dyes, aromatic compounds, or chlorinated hydrocarbons, into carbon dioxide, organic acids, and inorganic ions as end products [24]. The amount of high-temperature and high-pressure regions was increased due to the presence of semiconductor (i.e., TiO2, Al2O3) particles, which improved the process of breaking up the microbubbles produced by the ultrasonic irradiation into smaller bubbles [25] This causes an increase in the number of hydroxyl radicals produced, which attack the pollutant and cause it to degrade.
Additionally, nanocomposites are highly intriguing. To suggest environmentally responsible solutions to the world’s environmental challenges, this study has concentrated on the evaluation of a novel TiO2-(MoO3)/Al2O3 nanocomposite for environmental applications that were hydrothermally synthesized and characterized.

MATERIALS AND METHODS
 Alumina (nano material), Sodium molybdate dihydrate (Na2MoO4.2H2O) from Merck, Germany Titanium isopropoxide (97%, Sigma-Aldrich), ethanol (99.9%), hydrochloric acid (37%), Ascorbic acid, Sodium decyl sulfate (SDS).4

Procedure
Prepare TiO2 nano articles was as carried out according to previous published study by Mahata, S., et al. [26]. With some modifications. In brief, a combination of (2.5 ml) ethanol and (3.5 ml) diluted HCl was stirred while titanium isopropoxide (5 ml) was added dropwise to generate a clear solution. 10 ml of SDS (1.0 wt%) was added, and after being stirred for 15 seconds at room temperature, the mixture was placed to an autoclave lined with Teflon and heated to 110 C for 24 hours. The product was centrifuged, rinsed with water and ethanol, then dried at 60  for 24 hours after cooling to ambient temperature.
According to Michailovski, Alexej, and Greta R. Patzk [27] - MoO3 nano-belts have been prepared with some modifications by using 1 mmol of sodium molybdate dihydrate and 7 ml of diluted HCl (added in the form of drops) while stirring for 15 mintues. Then, 10 ml of ascorbic acid solution was added while mixing with a magnetic stirrer. the mixture was transferred to steel Teflon tube autoclave and hydrothermal reaction was carried out at 180  for 6 hr , the result is also separated and washed with water and ethanol , and dried in an oven at 70  for 5 hr.
Using the ultrasonic technique, the TiO2- Al2O3/MoO3 nanocomposite was made with a weight/weight ratio of (0.25gm/0.5gm/0.25gm) accordingly.
The required quantities of (powder) nanomaterials were dissolved in ethanol and placed in each component’s own baker before being shocked for two hours at 70  with an ultrasonic frequency of 60 HZ. The smaller solutions are then added to the bigger ones in the shape of drips while they are still in the ultrasonic at 70 . After that, the mixture is kept for an hour.
The product is then transferred from the solution to a magnetic stirrer while the ethanol is still liquid, washed with ethanol and water, and dried overnight at 60 .
The material was calcined at a temperature of 400, or 800 °C for 2 hours in ambient air (Germany’s Nabertherm P320 Controller) as the last phase. These calcination temperatures were chosen to enhance the synthetic binary oxide systems’ physicochemical characteristics, such as their crystalline structure.

Characterization
The size and stability of nanocomposites were determined using DLS and Zeta potential, respectively. SEM was used in conjunction with EDX to analyze the surface morphology and determine the elemental composition of the samples.

RESULTS AND DISCUSSION
The process of hydrothermal synthesis is the most widely used method for creating nanomaterials. It essentially employs a methodology based on solutions and reactions. From very low to very high temperatures, hydrothermal synthesis can be used to create nanomaterials. Low-pressure or high-pressure circumstances can be used to regulate the morphology of the materials to be synthesized, depending on the vapor pressure of the primary component in the process.
Both Al2O3 and TiO2 are utilized as distinct catalysts for numerous chemical activities and have a number of benefits. Particularly, TiO2 has high photocatalytic activity under UV irradiation but a very small specific surface area, whereas Al2O3 has better heat stability and a higher specific surface area but worse catalytic properties. Many researchers have tried to address these issues [28]. By combining the distinctive structural characteristics of the different oxides, materials with the benefits of the different oxides can be created, such as Mo/TiO2 materials for high-performance oxidative desulfurization [29].
Figs. 1a and b show the synthesized nanocomposite’s DLS and Zeta potentials analyses. The samples with 154 nm particle size, high (41.0 mV) Zeta potentials, and good values (0.700) of polydispersity index are suggestive of an efficient synthesis, according to the data (PDI),
Nano size is one of the essential properties of the synthesized material due to its effect on surface area. 
SEM and EDX studies were used to identify the morphology and components of the composite.
SEM images are displayed in Fig. 2A and the EDX Fig 2C.
The generated oxide NPs have a similar shape.
The NPs materials revealed aggregated spherical particles with average size about 35 nm. The purity of the TiO2- Al2O3/MoO3 NPs was confirmed by an EDX test (Fig. 2C,D)
Therefore, while colloids with low zeta potentials coagulate or flocculate, those with high negative or positive zeta potentials are stabilized [23,24]. Intermolecular interaction, lattice mismatch, and the presence of residual oxides were thought to be the causes of the variance in surface shape [64]. EDX examination, which exclusively detects aluminum, titanium, molybdenum, and oxygen, proved the purity of TiO2- Al2O3/MoO3 NPs.
The crystalline phases of anatase TiO2 and MoO3 and Al2O3 observed in the XRD patterns
of composite are shown in Fig. 3 and the patterns are well correlated with the JCPDS files (01-071-1167, 00-005-0506, and JCPDS 46-1212)).), respectively. It confirms the formation of crystalline MoO3 and alumina phase on the titanium dioxide surface Fig. 3.
The FT-IR spectra for all of the materials contained four characteristic bands: for stretching vibrations of ≡Ti–O (623 cm−1)  and Al–O–Ti/Mo (690 cm−1) and for hydroxyl group (–OH) bending vibrations (1600 cm−1)  and stretching vibrations (3500 cm−1) (Fig. 4).  The calcination temperature was found to influence the intensity of the characteristic bands for Ti–O and Al–O–Ti-Mo. The FT-IR analysis proved the effectiveness of the proposed synthesis methodology.

CONCLUSION
In conclusion, we have created a simple hydrothermal process that has produced a well-characterized TiO2-Al2O3/MoO3 nanocomposite.
The shape of the TiO2-Al2O3/MoO3 nanocomposite, size distribution, stability, dispersity, and zeta potentials all supported the validity of the good formation findings. In each of the aforementioned scenarios, we have identified how temperature and pressure affect the physicochemical properties of the TiO2-Al2O3/MoO3 nanocomposite intended for environmental applications.

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

 

 

1.    Zhu Q-L, Xu Q. Immobilization of Ultrafine Metal Nanoparticles to High-Surface-Area Materials and Their Catalytic Applications. Chem. 2016;1(2):220-245.
2.    Albukhaty S, Naderi-Manesh H, Tiraihi T, Sakhi Jabir M. Poly-l-lysine-coated superparamagnetic nanoparticles: a novel method for the transfection of pro-BDNF into neural stem cells. Artificial Cells, Nanomedicine, and Biotechnology. 2018;46(sup3):125-132.
3.    Abdelmigid HM, Morsi MM, Hussien NA, Alyamani AA, Alhuthal NA, Albukhaty S. Green Synthesis of Phosphorous-Containing Hydroxyapatite Nanoparticles (nHAP) as a Novel Nano-Fertilizer: Preliminary Assessment on Pomegranate (Punica granatum L.). Nanomaterials. 2022;12(9):1527.
4.    Albukhaty S, Al-Bayati L, Al-Karagoly H, Al-Musawi S. Preparation and characterization of titanium dioxide nanoparticles and in vitro investigation of their cytotoxicity and antibacterial activity against Staphylococcus aureus and Escherichia coli. Anim Biotechnol. 2020;33(5):864-870.
5.    Mahmood RI, Kadhim AA, Ibraheem S, Albukhaty S, Mohammed-Salih HS, Abbas RH, et al. Biosynthesis of copper oxide nanoparticles mediated Annona muricata as cytotoxic and apoptosis inducer factor in breast cancer cell lines. Sci Rep. 2022;12(1).
6.    Jihad MA, Noori FTM, Jabir MS, Albukhaty S, AlMalki FA, Alyamani AA. Polyethylene Glycol Functionalized Graphene Oxide Nanoparticles Loaded with Nigella sativa Extract: A Smart Antibacterial Therapeutic Drug Delivery System. Molecules. 2021;26(11):3067.
7.    Al-Kaabi WJ, Albukhaty S, Al-Fartosy AJM, Al-Karagoly HK, Al-Musawi S, Sulaiman GM, et al. Development of Inula graveolens (L.) Plant Extract Electrospun/Polycaprolactone Nanofibers: A Novel Material for Biomedical Application. Applied Sciences. 2021;11(2):828.
8.    Willemsen L, Wichers J, Xu M, Van Hoof R, Van Dooremalen C, Van Amerongen A, et al. Biosensing Chlorpyrifos in Environmental Water Samples by a Newly Developed Carbon Nanoparticle-Based Indirect Lateral Flow Assay. Biosensors. 2022;12(9):735.
9.    Jabir M, Sahib UI, Taqi Z, Taha A, Sulaiman G, Albukhaty S, et al. Linalool-Loaded Glutathione-Modified Gold Nanoparticles Conjugated with CALNN Peptide as Apoptosis Inducer and NF-κB Translocation Inhibitor in SKOV-3 Cell Line. International Journal of Nanomedicine. 2020;Volume 15:9025-9047.
10.    Rassaei L, Marken F, Sillanpää M, Amiri M, Cirtiu CM, Sillanpää M. Nanoparticles in electrochemical sensors for environmental monitoring. TrAC, Trends Anal Chem. 2011;30(11):1704-1715.
11.    Khashan KS, Sulaiman GM, Abdulameer FA, Albukhaty S, Ibrahem MA, Al-Muhimeed T, et al. Antibacterial Activity of TiO2 Nanoparticles Prepared by One-Step Laser Ablation in Liquid. Applied Sciences. 2021;11(10):4623.
12.    Jafari Eskandari M, Hasanzadeh I. Size-controlled synthesis of Fe3O4 magnetic nanoparticles via an alternating magnetic field and ultrasonic-assisted chemical co-precipitation. Materials Science and Engineering: B. 2021;266:115050.
13.    Ali Dheyab M, Aziz AA, Jameel MS. Recent Advances in Inorganic Nanomaterials Synthesis Using Sonochemistry: A Comprehensive Review on Iron Oxide, Gold and Iron Oxide Coated Gold Nanoparticles. Molecules. 2021;26(9):2453.
14.    Arya S, Mahajan P, Mahajan S, Khosla A, Datt R, Gupta V, et al. Review—Influence of Processing Parameters to Control Morphology and Optical Properties of Sol-Gel Synthesized ZnO Nanoparticles. ECS Journal of Solid State Science and Technology. 2021;10(2):023002.
15.    Gupta T, Samriti, Cho J, Prakash J. Hydrothermal synthesis of TiO2 nanorods: formation chemistry, growth mechanism, and tailoring of surface properties for photocatalytic activities. Materials Today Chemistry. 2021;20:100428.
16.    Yu S, Dong X, Zhao P, Luo Z, Sun Z, Yang X, et al. Decoupled temperature and pressure hydrothermal synthesis of carbon sub-micron spheres from cellulose. Nature Communications. 2022;13(1).
17.    Zuo B, Li W, Wu X, Wang S, Deng Q, Huang M. Recent Advances in the Synthesis, Surface Modifications and Applications of Core‐Shell Magnetic Mesoporous Silica Nanospheres. Chemistry – An Asian Journal. 2020;15(8):1248-1265.
18.    Li K, de Rancourt de Mimérand Y, Jin X, Yi J, Guo J. Metal Oxide (ZnO and TiO2) and Fe-Based Metal–Organic-Framework Nanoparticles on 3D-Printed Fractal Polymer Surfaces for Photocatalytic Degradation of Organic Pollutants. ACS Applied Nano Materials. 2020;3(3):2830-2845.
19.    Mesoporous WO3/TiO2 Nanocomposites Photocatalyst for Rapid Degradation of Methylene Blue in Aqueous Medium. International Journal of Engineering. 2019;32(10).
20.    Hanh NT, Van Thuan D, Khai NM, Thuy PT, Hang TTM, Vy NHT, et al. Synthesis of Co3O4 coated on N,S doped TiO2 for novel photocatalytic degradation of toxic organic pollutant in aqueous environment. Ceram Int. 2020;46(13):21610-21616.
21.    Cardoso IMF, Cardoso RMF, da Silva JCGE. Advanced Oxidation Processes Coupled with Nanomaterials for Water Treatment. Nanomaterials. 2021;11(8):2045.
22.    Kurian M. Advanced oxidation processes and nanomaterials -a review. Cleaner Engineering and Technology. 2021;2:100090.
23.    Oturan MA, Aaron J-J. Advanced Oxidation Processes in Water/Wastewater Treatment: Principles and Applications. A Review. Crit Rev Environ Sci Technol. 2014;44(23):2577-2641.
24.    Augugliaro V, Litter M, Palmisano L, Soria J. The combination of heterogeneous photocatalysis with chemical and physical operations: A tool for improving the photoprocess performance. Journal of Photochemistry and Photobiology C: Photochemistry Reviews. 2006;7(4):127-144.
25.    Li W, Zheng S, Chen Q, Cao B. A new method for surface modification of TiO2/Al2O3 nanocomposites with enhanced anti-friction properties. Materials Chemistry and Physics. 2012;134(1):38-42.
26.    Mahata S, Mahato SS, Nandi MM, Mondal B. Synthesis of TiO2 nanoparticles by hydrolysis and peptization of titanium isopropoxide solution.  AIP Conf Proc: AIP; 2012.
27.    Michailovski A, Patzke GR. Hydrothermal Synthesis of Molybdenum Oxide Based Materials: Strategy and Structural Chemistry. Chemistry - A European Journal. 2006;12(36):9122-9134.
28.    Abate S, Mebrahtu C, Giglio E, Deorsola F, Bensaid S, Perathoner S, et al. Catalytic Performance of γ-Al2O3-ZrO2-TiO2-CeO2 Composite Oxide Supported Ni-Based Catalysts for CO2 Methanation. Industrial & Engineering Chemistry Research. 2016;55(16):4451-4460.
29.    Du Y, Zhou L, Liu Z, Guo Z, Wang X, Lei J. Designed formation of mesoscopical order of ionic liquid-based meso/macroporous Mo/TiO2 materials for high-performance oxidative desulfurization. Chem Eng J. 2020;387:124056.