Magnesium-zinc-tin-oxide photocatalyst antibacterial nanoparticles and large-scale manufacturing method thereof

Description

[0001] MAGNESIUM- ZINC-TIN-OXIDE PHOTOCATALYST ANTIBACTERIAL NANOPARTICLES AND LARGE-SCALE MANUFACTURING METHOD THEREOF

[0002] TECHNICAL FIELD

[0003] The invention is related to a solution-based chemical manufacturing method for large-scale manufacturing of magnesium-doped zinc-tin-oxide nanoparticles at low temperatures (<100°C) and in a very short time (~5 hours) using an eco-friendly agent molecule instead of hydrazine. The mentioned agent molecule was employed for the first time in the synthesis of magnesium-doped zinc-tin oxide nanoparticles.

[0004] BACKGROUND

[0005] In the state of the art, zinc-tin-oxide nanoparticles are produced by three different methods: solid-state, solution and vacuum-based techniques. Among them, vacuum-based methods are unsuitable for large-scale industrial manufacturing due to the necessity for high-cost machinery and equipment and long-term processing. On the other hand, the solid-state method is not preferred in large-scale industrial manufacturing due to the requirement for multiple repeated annealing processes at high temperatures for crystallization of these nanoparticles and the relatively poor yield of high purity products.

[0006] Among the three methods, solution-based methods are the most suitable for industrial manufacturing. The main drawback of solution-based methods is that the product is obtained in an amorphous structure after manufacturing and requires annealing at high temperatures (>500°C) to get the crystalline form. To overcome this problem, a hydrazine reduction molecule is commonly used in the synthesis stage. However, this process is still not preferred in industrial manufacturing due to the high toxicity of the hydrazine chemical and the relatively low synthesis temperature (~200°C) but long synthesis time (>20 hours).

[0007] In the article entitled “Ali, M. B., Nasser, R., Alshahrani, S. M., Al-Shamiri, H. A., Elgammal, B., Elhouichet, H. 2021. “Synthesis, characterization, and visible-light photocatalytic activity of transition metals doped ZTO nanoparticles” (Ceramics International, 47 (23), 32882-32890)”, Mg-doped zinc-tin-oxide nanoparticles were produced by vacuum-based hydrothermal method under 200°C for 20 hours. This method is not suitable for industrial manufacturing due to the high cost of the vacuum requirements and the necessity for long-term processing. Furthermore, the work only examined at a 2% Mg doping, and it was reported that the photocatalytic properties were poor when compared to other metals.

[0008] AIM OF THE INVENTION

[0009] The main challenge for oxide-based photocatalyst inorganic nanoparticles is that they require long-term processing in vacuum-based methods or high- temperature annealing in solution-based methods to get the necessary crystal structure. The sol-gel method, which is the most suitable for industrial applications, requires annealing at high temperatures for crystallization due to the amorphous structure of the product during manufacturing, which limits its commercialization. These factors seriously hinder the large-scale manufacturing and marketing of these materials.

[0010] A solution-based chemical manufacturing method modified with a reduction molecule for synthesizing oxide-based inorganic photocatalytic nanoparticles in the desired crystalline form and particle size at low temperatures (<100 °C) without requiring a vacuum environment has been developed within the scope of our invention to address the aforementioned technical issues. Thus, these nanoparticles utilized in a variety of technologies will help to provide a high-tech solution for massive chemical manufacturing.

[0011] DETAILED DESCRIPTION OF THE INVENTION

[0012] The invention is related to a solution-based chemical manufacturing method for large-scale manufacturing of magnesium-doped zinc-tin-oxide nanoparticles at low temperatures (<100°C) and in a very short time (~5 hours) using an eco-friendly agent molecule instead of hydrazine. The mentioned agent molecule was employed for the first time in the synthesis of magnesium-doped zinc-tin oxide nanoparticles.

[0013] In the synthesis of ternary zinc-tin-oxide nanoparticles, sodium borohydride (NaBH4), an eco-friendly inorganic compound, was employed as a reducing agent molecule instead of the toxic hydrazine (N2H4). The chemical mechanism for the synthesis of ternary zinc-tin-oxide nanoparticles using sodium borohydride (NaBH4) as a reducing agent molecule is as follows: mZnCh + ySnCk + nNaBH4+ xH2O (1 )

[0014] (ZnCI2)m(BH4)n(SnCl4)y + nNaOH + H2(gas) (2) mZn(OH)2+ ySn(OH)4+ nNaCI + 2BO2-+ H2(gas) (3)

[0015] Zn2SnC>4 (veya ZnSnOs) + 2BHzr + 4H2O (4)

[0016] In Equation 1 , the starting chemicals zinc chloride (ZnCI2) as zinc source and tin chloride (SnCk) as tin source were allowed to dissolve separately in 20mL of deionized water (H2O). These solutions were then mixed together and magnesium nitrate (Mg(NOs)2) was added as a magnesium source into solutions. Since this dopant will be replaced by zinc in the structure, it performed similarly to zinc chloride throughout the reaction phase. The sodium borohydride (NaBH4) compound was then added into this solution with a Zn / NaBH4 mole ratio of 1 :90. The values of m, y and x in the equations can be at least one of the ratios 2:1 :4 and 1 :1 :3, respectively, to produce the final product at the appropriate stoichiometry.

[0017] In Equation 2, the sodium borohydride compound reacting with water undergoes hydrolysis to form sodium ion (Na+) and tetrahydroborate ion (BH^r). Whilst the tetrahydroborate ions in the Lewis structure forms H4B-BH4 bridge between zinc and tin ions, the sodium ion reacts with hydroxyl ions to form sodium hydroxyl (NaOH) compound. Additionally, the hydrolysis reaction of sodium borohydride leads to the formation of the well-known hydrogen gas (H2).

[0018] In Equation 3, NaOH compound, which is widely used as a mineralizer, reacts with chlorine ions in metals to form sodium chloride (NaCI), while its hydroxyls in nature react with zinc ions to form Zn(OH)2and with tin ions to form Sn(OH)4. The tetrahydroborate ion between the two metals reacts with ambient water to form the strong basic metaborate ion (BO2‘) and hydrogen gas.

[0019] In Equation 4, the metaborate ion (BO2‘) reacts with hydrogen in the metals framework to regenerate tetrahydroborate ion and water, and thereby ternary zinc- tin-oxide (Zn2SnC>4 or ZnSnOs) nanoparticles are formed during this reaction.

[0020] The photocatalytic antibacterial effects of the as-synthesized product were investigated against S. aureus ve E. coli bacterial strains that cause nosocomial infections. It was observed that the developed product exhibited 99.97% and 96.96% antibacterial activity against E. coli ve S. aureus bacteria under visible light in only 1 hour, respectively.

[0021] The application steps of the manufacturing method for our invention are as follows:

[0022] • Zinc chloride (0.008 mol%) and tin chloride (0.004 mol%) are mixed separately in 20 mL of deionized water for 1 hour.

[0023] • The zinc and tin solutions are combined in a beaker and magnesium nitrate (1 .5 mol%) is added into solution and then stirred for 1 hour.

[0024] • Then, sodium borohydride compound as the reducing agent molecule is added into the solution with a Zn / NaBH4 mole ratio of 1 :90 and then the solution is stirred at 70°C temperature for 5 hours.

[0025] • The solution is precipitated by centrifugation and then the product is washed three times with water.

[0026] • The product is dried in room conditions at 50°C for 1 hour and the final product is obtained.

Claims

CLAIMS1. A method for manufacturing an antibacterial magnesium-zinc-tin-oxide photocatalyst nanoparticle characterized by comprising the steps below: dissolving the starting chemicals zinc chloride (ZnCh) as zinc source and tin chloride (SnCk) as tin source separately in deionized water (H2O) to form Equation 1, Equation 2, Equation 3 and Equation 4, respectively, combining the solutions and adding magnesium nitrate (Mg(NC>3)2), then adding sodium borohydride compound into this solution with a Zn / NaBH4 mole ratio of 1 : 90 mZnCh + ySnCU + nNaBH4+ XH2O (1 )(ZnCI2)m(BH4)n(SnCl4)y + nNaOH + H2(gas) (2) mZn(OH)2+ ySn(OH)4+ nNaCI + 2BO2’+ H2(gas) (3) Zn2SnC>4 (veya ZnSnOs) + 2BH4' + 4H2O (4).

2. The equation 1 mentioned in claim 1, characterized in that the values of m, y and x are at least one of the ratios 2:1 :4 and 1 :1 :3, respectively, to produce the final product in the appropriate stoichiometry.

3. A method for manufacturing an antibacterial magnesium-zinc-tin-oxide photocatalyst nanoparticle characterized by comprising the steps below:- Mixing zinc chloride (ZnCh) and stannous chloride (SnCk) separately in deionized water (H2O) for 1 hour,- Combining zinc and tin solutions in a beaker and adding magnesium nitrate (Mg(NOs)2) while mixing,- Adding the agent molecule sodium borohydride compound into the solution until the Zn / NaBH4 molar ratio is 1 :90.- Stirring the resulting solution at 70°C for 5 hours,- Sedimentation of the solution by centrifugation and then washing the resulting product with water,- drying the obtained product in room conditions at 50°C for 1 hour.

4. The method as claimed in claims 1 or 3, characterized in that the starting chemicals are zinc chloride (ZnCh) as the zinc source and stannous chloride(SnCk) as the tin source, in amounts of 0.008 mol% and 0.004 mol%, respectively.

5. The method mentioned in claims 1 or 3, characterized in that the amount of added magnesium nitrate (Mg(NOs)2) is 1.5 mol%.