Synthesis of a bismuth-bromine hybrid material for photocatalytic degradation of tetracycline hydrochloride

Abstract

The application discloses a bismuth-bromine-based inorganic-organic hybrid semiconductor and a preparation method and application thereof. The hybrid semiconductor has a molecular structural formula of (Etbtz)2Bi2Br 10 , wherein (Etbtz) 2+ is an ethylated benzothiazole cation with two positive charges, and a (Bi2Br 10 ) 4– anion in the material is a zero-dimensional anion structure formed by coordination of a trivalent bismuth ion and a bromine ion. By selecting bismuth bromide, manganese sulfate, benzothiazole, ethanol and hydrobromic acid as reaction raw materials, a single crystal of the compound (Etbtz)2Bi2Br 10 is obtained under a solvothermal condition, and the single crystal can be used for photocatalytic degradation of tetracycline hydrochloride.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photocatalytic tetracycline degradation, and particularly relates to a bismuth bromide-based hybrid material (Etbtz)2Bi2Br 10 and application thereof in photocatalytic degradation of tetracycline hydrochloride, wherein (Etbtz) 2+ is an ethylated benzothiazole cation. BACKGROUND

[0002] As a kind of widely used drugs, antibiotics such as tetracycline, penicillin, sulfonamide, quinolone and macrolide play an important role in medical and breeding fields. However, the large-scale use of antibiotics leads to a large amount of discharge into natural water, soil and wastewater treatment systems, causing serious antibiotic pollution problems. Antibiotic pollution has an undeniable impact on the environment. Antibiotic residues can affect the health of aquatic organisms and disrupt the balance of aquatic ecosystems. In addition, antibiotics can also lead to bacterial resistance, reducing the efficacy of antibiotics in the medical field. Therefore, it is of great significance to find efficient and environmentally friendly antibiotic degradation technology.

[0003] Photocatalytic antibiotic degradation is a method that uses photocatalytic process to decompose antibiotics into non-toxic or low-toxic substances to address the potential risks of antibiotic pollution to the environment and human health. Photocatalytic antibiotic degradation has many advantages. First, it is a very effective method that can effectively decompose antibiotic molecules in a short time. Second, the photocatalytic process can be carried out at room temperature without the need for additional chemical reagents, thus having lower cost and environmental risk. In addition, photocatalytic technology can also be applied to wastewater treatment systems to improve antibiotic removal efficiency. In this process, the selection of photocatalyst is crucial.

[0004] Among the many semiconductor materials that can be used as photocatalysts, inorganic-organic hybrid perovskite materials have received widespread attention due to their suitable band gap, controllable structure and good stability. However, most of the hybrid perovskite materials currently used are lead-based perovskites, which are toxic to the human body and the environment. Therefore, it is necessary to develop non-toxic and stable hybrid perovskite materials for photocatalytic degradation of antibiotics. SUMMARY

[0005] The purpose of the present application is to provide a bismuth bromide inorganic-organic hybrid semiconductor material that can photocatalytically degrade tetracycline hydrochloride solution. Bismuth bromide is used as the inorganic component, which has very low toxicity; ethylated benzothiazole is selected as the organic cation, and (Etbtz) 2+ cation is introduced through alkylation reaction to improve the water stability of the material. The material is easy to synthesize with cheap and readily available raw materials, simple synthesis method, good stability and excellent performance in photocatalytic degradation of tetracycline hydrochloride.

[0006] The technical scheme of the present application comprises the following contents:

[0007] 1. An inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 , wherein (Etbtz) 2+ represents ethylated benzothiazole cation, which is formed by in-situ ethylation reaction of nitrogen atom in benzothiazole. The compound is crystallized in triclinic system, P-1 space group, and the unit cell parameters are

[0008] α=100.7 (3) °, β=97.6 (3) °, γ=99.4 (3) °. The material appears as light yellow needle-like crystal, and the structure type is ionic inorganic-organic hybrid. The cation is ethylated benzothiazole, and the anion is zero-dimensional binuclear (Bi2Br 10 ) 4- structure formed by coordination of trivalent bismuth ion and bromide ion, and the two are interacted through ionic bond, and the whole material is electrically neutral.

[0009] 2. A preparation method of the inorganic-organic bismuth bromide hybrid semiconductor according to item 1, characterized in that: bismuth bromide, manganese sulfate monohydrate and benzothiazole with a molar ratio of 2:1:1 are weighed, dissolved in a mixed solution of hydrobromic acid and ethanol with a volume ratio of 1:1, and a light yellow crystalline product, i.e. (Etbtz)2Bi2Br 10 is obtained under solvothermal conditions.

[0010] 3. Use of the inorganic-organic bismuth bromide hybrid semiconductor according to item 1, characterized in that: the compound has excellent water stability and photocatalytic degradation tetracycline performance, and is used as an antibiotic degradation photocatalyst.

[0011] The present application has the advantages that the synthesis conditions of the product are simple, easy to control and pollution-free, the combination of alkylated benzothiazole and inorganic (Bi2Br 10 ) 4- anion at the molecular level is realized, the water stability is good, and the photocatalytic degradation of tetracycline hydrochloride residue can be directly carried out in aqueous solution. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a molecular structure diagram of the inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 .

[0013] Figure 2 is a partial structure diagram of the anion in the inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 .

[0014] Figure 3Inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 The space packing diagram of the molecules in the unit cell.

[0015] Figure 4 Inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 The powder diffraction pattern of the as-synthesized powder is in full agreement with the powder simulation diffraction results.

[0016] Figure 5 Inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 The infrared spectrum of the as-synthesized powder.

[0017] Figure 6 Inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 The solid ultraviolet absorption spectrum of the as-synthesized powder.

[0018] Figure 7 Fig. a is a graph showing the change of the absorption spectrum of tetracycline hydrochloride solution with time, Fig. b is a photocatalytic tetracycline hydrochloride degradation kinetics curve of inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 Fig. c is a first-order kinetics curve of inorganic-organic bismuth bromide hybrid semiconductor (Etbtz)2Bi2Br 10 . DETAILED DESCRIPTION

[0019] (1) Synthesis of compound (Etbtz)2Bi2Br 10

[0020] Put 0.224 g of BiBr3, 0.043 g of manganese sulfate monohydrate and 0.2 mL of benzothiazole into a quartz reaction bottle with a 25 mL polytetrafluoroethylene liner, add 3 mL of hydrobromic acid and 3 mL of ethanol, then put the polytetrafluoroethylene liner into a stainless steel reaction kettle, tighten it and place it in a 140℃ oven for heating, and keep it at this temperature for three days, then cool it to room temperature, and after ethanol washing, a light yellow crystalline material is obtained, which is compound (Etbtz)2Bi2Br 10 The purity and yield of the crystals obtained under the above reaction conditions are high.

[0021] (2) Use of compound (Etbtz)2Bi2Br 10 for photocatalytic tetracycline hydrochloride degradation

[0022] Add 20 mL of tetracycline hydrochloride solution with a concentration of 20 mg / L to the reaction cell, and add 50 mg of the well-ground (Etbtz)2Bi2Br 10 ​The powder was dispersed in the solution, and magnetic stirring was carried out in dark conditions for 30 min to reach adsorption dissociation equilibrium. The reaction tank was supplied with cooling water to keep it at room temperature, and irradiation was carried out for 3 h continuously using a 300 W Xe lamp with a light power density of 500 mW-cm -2 . Sampling was carried out every 30 min, and testing was carried out using an ultraviolet-visible light spectrophotometer.

Claims

1. An inorganic-organic bismuth-bromine hybrid semiconductor, characterized in that... The molecular formula of this hybrid semiconductor is (Etbtz)2Bi2Br 10 It exhibits an ionic hybrid structure, in which the cation is an ethylbenzothiazole cation (Etbtz). 2+ The anion is formed by octahedral edge-sharing (Bi2Br). 10 ) 4- The binuclear anion, this bismuth-bromine hybrid semiconductor, crystallizes in the triclinic crystal system, space group P-1, with unit cell parameters of [missing information]. α=100.7(3)°, β=97.6(3)°, γ=99.4(3)°.

2. A method for preparing the inorganic-organic bismuth bromide hybrid semiconductor according to claim 1, characterized in that: Bismuth bromide, manganese sulfate monohydrate, and benzothiazole were dissolved in a mixture of hydrobromic acid and ethanol. The solution was kept at 140°C for three days. After cooling to room temperature, a pale yellow crystalline substance was obtained, which was compound (Etbtz)2Bi2Br. 10 .

3. The use of the bismuth-bromine hybrid semiconductor according to claim 1, characterized in that: This semiconductor is used for the photocatalytic degradation of tetracycline hydrochloride.

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