Preparation and application of MoSe2 quantum dots loaded titania sub-oxide nanotube array photoanode

Abstract

The application belongs to the technical field of environmental engineering, and discloses a preparation and application of a MoSe2 quantum dot loaded sub-titanium dioxide nanotube array photo-anode. 3+ Excess elemental Se forms MoSe2 at defect sites, simultaneously participates in regulating the heterojunction interface electric field, optimizes the charge distribution at the defect sites, reduces the tendency of conversion to high valence state in the catalytic process, and improves the catalytic stability of the system. In the catalytic reaction process, the confinement effect of TiO2 NTA on MoSe2 QD and the charge transfer effect mediated by the interface electric field can synergistically regulate the migration and conversion path of electrons in the system, reduce the reaction energy barrier of active species, and effectively increase the amount of active species produced. The electrode material preparation method is simple, easy to mass production, and can be used to replace the electro-oxidation anode material by simply modifying the existing electrochemical equipment and setting up a waterproof LED light source at the device photo-anode to build a photoelectrocatalytic degradation device, saving the modification cost.

Description

Technical Field

[0001] This invention belongs to the field of environmental engineering technology and involves the research on the preparation technology of titanium suboxide nanotube array electrode material supported by molybdenum diselenide quantum dots. In particular, it involves the innovation of using this material as an anode to construct a photoelectrocatalytic degradation system for the degradation of typical industrial wastewater. Background Technology

[0002] Environmental pollution caused by pharmaceutical wastewater has attracted global attention, and eliminating its threat to ecological security and human health is a current research hotspot and challenge in the field of environmental engineering.

[0003] Photoelectrocatalysis is a highly efficient method for degrading organic pollutants. Its advantage lies in coupling photocatalysis and electrocatalysis through a catalytic electrode to achieve synergistic catalytic effects. The performance of the photoelectrode catalytic material plays a crucial role. Therefore, research on the preparation of highly catalytically active photoanodes and the photoelectrocatalytic degradation mechanism targeting antibiotics and resistance genes in wastewater is of significant practical importance for achieving efficient degradation and detoxification of pharmaceutical wastewater. The articles "Efficient electrochemical oxidation of COVID-19 treatment drugs favipiravir by a novel flow-through Ti / TiO2-NTA / Ti4O7 anode," "Cu2O on anodized TiO2 nanotube arrays: Aheterojunction photoanode for visible light assisted electrochemical degradation of pharmaceuticals in water," and "Effective degradation of aqueous carbamazepine on a novel blue-colored TiO2 nanotube arrays membrane filter anode" respectively investigated the use of electrode materials such as Ti / TiO2-NTA / Ti4O7, Cu2O-modified TiO2 NTA, and defective TiO2 NTA for the degradation of favipiravir, ciprofloxacin, and carbamazepine. Although these studies improved the degradation capacity of photoanodes for pharmaceutical wastewater, the deep treatment of pharmaceutical wastewater resulted in low electron utilization and high energy consumption. Furthermore, traditional photoelectrocatalytic degradation systems... ·OH has poor ability to reduce resistance genes, making it difficult to achieve deep removal of resistance genes from wastewater. Therefore, it is necessary to develop an effective electrode material that can improve the mass transfer efficiency of the electrode surface while generating active species with selective degradation capabilities for resistance genes.

[0004] TiO2 nanotube arrays (TiO2 NTA) are high-performance photoelectrocatalytic materials. Their hollow, ordered spatial structure meets the substrate requirements of confined catalytic materials, and the abundant oxygen vacancies on the surface can serve as anchoring sites to enhance the stability of the supported catalytic material. MoS2 is a typical transition metal disulfide with abundant sulfur active sites, catalytic stability, and unique physicochemical properties (narrow band gap, presence of vacancies). However, the main electrocatalytic active sites in this type of material are at the edges of MoS2, making it susceptible to surface adsorption and suppression of catalytic performance. Therefore, it is necessary to find alternative materials with similar physicochemical properties and superior catalytic performance. MoSe2 is a semiconductor material with a two-dimensional layered structure, similar to molybdenum disulfide (MoS2), possessing advantages such as a narrow band gap, excellent mechanical properties, resistance to photocorrosion, moderate interlayer spacing, and large specific surface area. Furthermore, the metallic properties of Se enhance the conductivity of MoSe2 materials, effectively improving carrier migration rates. By combining defect engineering and heterostructure construction strategies, loading MoSe2 semiconductors into the nanotube cavity of TiO2 NTA photoanodes can create a confinement effect between active sites (MoSe2) and defect sites (TiO2 NTA oxygen vacancies), thereby regulating the heterojunction interface structure and constructing a special band structure—the Dirac cone. The synergistic charge transfer effect can increase carrier mobility conversion rate, reduce the interface energy barrier, and improve photoelectrocatalytic performance.

[0005] Therefore, this invention employs a synergistic strategy of interface modulation and confined catalysis. MoSe2 is anchored onto the surface of titanium suboxide nanotubes using a solvothermal method, and the interface structure and oxygen vacancy structure of the substrate on the MoSe2 heterojunction are controlled by calcination to form a molybdenum diselenide quantum dot-supported titanium suboxide nanotube array (MoSe2QD / TiO2 NTA) photoanode material. By controlling the Fermi level of the system through the heterojunction interface structure, the interface energy barrier is lowered, carrier transition and transfer rates are improved, and the photoelectrocatalytic performance of the material is enhanced. Based on MoSe2QD / TiO2 NTA, a photoelectrocatalytic degradation system is constructed. Adjusting the interfacial electric field and surface defect structure in the material structure promotes the catalytic activity and stability of the photoanode, achieving the goal of mineralization and detoxification of the degradation system through the synergistic enhancement of confinement and charge transfer effects. Summary of the Invention

[0006] This invention provides a method for preparing a molybdenum diselenide quantum dot-supported titanium suboxide nanotube array electrode, and applies it to a photoelectrocatalytic degradation system for the degradation of antibiotics and resistance genes in wastewater. MoSe2 QD / TiO2 NTA photoelectrocatalytic materials are prepared by anchoring MoSe2 at defect sites (oxygen vacancies) on a TiO2 NTA substrate surface. The heterojunction interface structure of the material is controlled by adjusting the preparation conditions, and the interfacial electric field is optimized. The synergistic effect between the active sites (MoSe2 QD) and defect sites (TiO2 NTA) is utilized to regulate the Fermi level of the system, reduce the interfacial energy barrier, and increase the electron transition and transfer rates. Simultaneously, the TiO2 NTA exerts a confinement effect on the MoSe2 QD loaded on its surface, effectively increasing the d-band center of Ti and reducing... · The Gibbs free energy of OH desorption is beneficial to the generation and desorption of active oxide species in the system.

[0007] The technical solution of the present invention:

[0008] A method for preparing a MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode includes the following steps:

[0009] Step 1: Refer to "Unraveling the reinforced photoelectrocatalytic activity and stability via unique configuration of P 3+ -O v -Ti 3+ in TiO 2-x The article "nanotube array" describes the in-situ fabrication of titanium suboxide nanotube array electrodes (TiO2NTA) on the surface of a flat titanium electrode plate using an electrolithography method.

[0010] Step 2: Using TiO2 NTA as a substrate, select elemental Se with reducing ability and sodium molybdate as reaction precursors, with a molar ratio of 3:1 to 2:1. Use 1-ethyl-3-methylimidazolium acetate ionic liquid as the reaction solvent, and control the sodium molybdate concentration to 0.01-0.1 mol / L. Use a solvothermal method, with a reaction temperature of 140-200℃ and a reaction time of 8-24 h. After the solvothermal reaction, remove the electrode material and anneal it (at 400℃ in air for 2 h). Finally, refer to "Unraveling thereinforced photoelectrocatalytic activity and stability via unique configuration of P 3+ -O v -Ti 3+ in TiO 2-xThe electrode was electrochemically reduced using the "nanotube array" method to obtain a MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode (MoSe2 QD / TiO2 NTA) photoelectrocatalytic material.

[0011] An application of a MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode in pharmaceutical wastewater treatment involves using a MoSe2 QD / TiO2 NTA electrode as the photoanode and a titanium mesh as the cathode, with an electrode spacing of 1-2 cm to construct an electrochemical reaction system. The distance between the light source and the photoanode is 5-12 cm, and the light source wavelength range is 420-780 nm (visible light). The system operates in a constant current mode with a current density of 1-10 mA / cm². 2 Using a DC power supply, simulated wastewater containing ciprofloxacin hydrochloride, sulfamethoxazole, 5-fluorouracil, and 2,4,6-trichlorophenol at concentrations of 100 μg / L-50 mg / L, as well as actual pharmaceutical wastewater containing the above pollutants (COD range 300-1000 mg / L), were used as target water bodies. The reaction time was 30 min. The removal rate of the target pollutants in the effluent was maintained above 98%, while the COD removal rate for the actual pharmaceutical wastewater was 60-94%.

[0012] The beneficial effects of this invention are as follows: This invention employs a synergistic strategy of interface modulation and confined catalysis. It utilizes oxygen vacancies (defect structures) on the surface of a TiO2NTA substrate to capture MoSe2 quantum dots (MoSe2 QDs). Through solvothermal modulation of the interface structure between the MoSe2 QDs and the substrate, the interaction between the active sites and the substrate is enhanced, forming a stable MoSe2 QD-supported TiO2 NTA (MoSe2 QD / TiO2 NTA) photoanode material. By modulating the Fermi level of the system through the heterojunction interface structure, the interface energy barrier is lowered, and the transition of photogenerated carriers is improved, thereby enhancing the catalytic activity of the material. In step 2, excess elemental Se is present at the defect sites (Ti... 3+ MoSe2 is generated at the site and simultaneously participates in regulating the electric field at the heterojunction interface, optimizing Ti. 3+ The charge distribution at the site can reduce the tendency for the substance to transform to a higher valence state during catalysis, thereby improving the catalytic stability of the system. During the catalytic reaction, the confinement effect of TiO2 NTA on MoSe2 QD and the charge transfer effect mediated by the interfacial electric field can synergistically regulate the electron migration and transformation pathways within the system, reduce the reaction energy barrier for the generation of active species, and effectively increase the amount of active species generated in the system. Based on MoSe2 QD / TiO2 NTA, a photoelectrocatalytic degradation system was constructed. The confinement effect and charge transfer effect were used to synergistically enhance the photoelectrocatalytic degradation and mineralization performance, thereby achieving the deep removal of recalcitrant organic matter from wastewater. Attached Figure Description

[0013] Figure 1The images show the TEM and corresponding EDS surface scans of MoSe2 QD / TiO2 NTA-003-12, where (a) is the TEM image of MoSe2 QD / TiO2 NTA-003-12, (b) is the surface scan of Ti element in MoSe2 QD / TiO2 NTA-003-12, (c) is the surface scan of O element in MoSe2 QD / TiO2 NTA-003-12, (d) is the surface scan of Mo element in MoSe2 QD / TiO2 NTA-003-12, and (e) is the surface scan of Se element in MoSe2 QD / TiO2 NTA-003-12.

[0014] Figure 2 Comparison of oxygen vacancies in MoSe2 QD / TiO2 NTA-003-12 and TiO2 NTAESR.

[0015] Figure 3 XPS spectra of MoSe2 QD / TiO2 NTA-003-12 and TiO2 NTA are shown, where (a) is the total XPS spectrum of MoSe2 QD / TiO2 NTA-003-12 and TiO2 NTA, and (b) is the Ti2p spectrum of MoSe2 QD / TiO2 NTA-003-12 and TiO2 NTA. Detailed Implementation

[0016] The specific embodiments of the present invention will be described in detail below with reference to the technical solutions and accompanying drawings.

[0017] Example 1

[0018] Preparation of MoSe2 QD / TiO2 NTA electrode material:

[0019] Reference "Unraveling the reinforced photoelectrocatalytic activity andstability via unique configuration of P 3+ -O v -Ti 3+ in TiO 2-xThe article on "nanotube array" describes a method for preparing the electroetching solution. Specifically, ethylene glycol, ammonium fluoride, and water are mixed in a mass ratio of 90:5:5 and magnetically stirred until the ammonium fluoride dissolves to form the electroetching solution. A titanium plate electrode is used as the anode and placed in the electroetching reactor. Lead oxide electrodes are used as the cathode, placed on either side of the titanium plate electrode with a 5cm gap between them. The reaction is carried out at a constant voltage of 35V for 3 hours, with the temperature controlled in a constant-temperature water bath between 20-25℃. After the reaction, the etched titanium plate electrode is removed, placed in deionized water, and sonicated for 10 minutes. It is then dried in an oven at 60℃ to obtain a titanium suboxide nanotube array electrode (TiO2 NTA).

[0020] Using TiO2 NTA as a substrate, elemental Se with reducing power and sodium molybdate were selected as the reaction precursors in a molar ratio of 3:1. 1-Ethyl-3-methylimidazolium acetate ionic liquid was used as the reaction solvent, and the sodium molybdate concentration was 0.03 mol / L. A solvothermal method was employed, with a reaction temperature of 160℃ and a reaction time of 12 h. After the solvothermal reaction, the electrode material was removed and annealed (at 400℃ for 2 h in air). Finally, referring to "Unraveling the reinforced photoelectrocatalytic activity and stability via unique configuration of P...", the final result was determined. 3+ -O v -Ti 3+ in TiO 2-x The "nanotube array" method was used to electrochemically reduce the electrode. Specifically, the annealed electrode was used as the cathode, the lead oxide electrode as the anode, and a 10% wt ammonium sulfate aqueous solution was used as the electrolyte. A constant current of 3 mA / cm² was maintained. 2 Electrochemical reduction for 2 min yielded MoSe2 QD / TiO2 NTA-003-12 photoelectrocatalytic material.

[0021] Using the above method, a series of MoSe2 QD / TiO2 NTA electrode materials (named MoSe2 QD / TiO2 NTA-002-12, MoSe2QD / TiO2 NTA-005-12 and MoSe2 QD / TiO2 NTA-010-12) were prepared by changing the sodium molybdate concentration in solvothermal mode to 0.02, 0.05 and 0.1 mol / L.

[0022] In addition, a series of MoSe2QD / TiO2 NTA electrode materials (named MoSe2 QD / TiO2 NTA-003-8, MoSe2 QD / TiO2NTA-003-16 and MoSe2 QD / TiO2NTA-003-24) were prepared by changing the solvothermal time to 8, 16 and 24 h using the above method.

[0023] Comparative Example 1

[0024] Using the same preparation method as in Example 1, but changing the solvent in the solvothermal reaction, and replacing the 1-ethyl-3-methylimidazolium acetate ionic liquid with deionized water, MoSe2 QD / TiO2 NTA-003-12-H2O was prepared.

[0025] Comparative Example 2

[0026] Using the same preparation method as in Example 1, but replacing MoSe2 with MoS2, the preparation method is as follows: 0.175g of thiourea and 0.145g of Na2MoO4·2H2O were dispersed in 100ml of deionized water and stirred for 30min. 0.117g of citric acid was added to the above solution, and magnetic stirring was continued for 10min to form a homogeneous mixture. TiO2 and NTA were then immersed in the above solution and placed in a reaction vessel. The reaction was carried out at 200℃ for 12h. After the solvothermal reaction, the electrode material was removed and annealed (at air atmosphere and 400℃ for 2h). The annealed electrode was used as the cathode, lead oxide as the anode, and a 10% wt ammonium sulfate aqueous solution was used as the electrolyte. A constant current of 3mA / cm was maintained. 2 Electrochemical reduction for 2 min yielded MoS2 QD / TiO2 NTA photoelectrocatalytic material.

[0027] Example 2

[0028] Electrochemical performance testing:

[0029] A three-electrode system was constructed using MoSe2 QD / TiO2 NTA series electrode materials as the working electrode, a platinum sheet of the same size as the counter electrode, and a calomel electrode as the reference electrode. The electrolyte was a 0.02 mol / L Na2SO4 aqueous solution. The electrochemical impedance spectroscopy (EIS) and open-circuit voltage (OCP) of the MoSe2 QD / TiO2 NTA series electrode materials were measured using an electrochemical workstation.

[0030] The EIS spectra of this series of electrode materials show that the conductivity of the materials first increases and then decreases with increasing sodium molybdate concentration, with MoSe2 QD / TiO2 NTA-003-12 exhibiting the best conductivity. This indicates that the MoSe2 loading can effectively control the electron migration efficiency on the electrode surface. Furthermore, OCP testing revealed that the MoSe2QD / TiO2 NTA-003-12 electrode generated the largest potential difference after visible light irradiation, suggesting that a suitable interfacial structure between MoSe2 and TiO2 NTA can effectively improve the photogenerated carrier migration capability of the system.

[0031] Example 3

[0032] Typical simulated pharmaceutical wastewater degradation test using photoelectrocatalytic system:

[0033] MoSe2 QD / TiO2 NTA-002-12, MoSe2 QD / TiO2 NTA-003-12, MoSe2 QD / TiO2 NTA-005-12, and MoSe2 QD / TiO2 NTA-010-12 were used as photoanodes, and titanium mesh was used as the cathode. The electrode spacing was 1 cm to construct a photoelectrocatalytic system. The distance between the light source and the photoanode was 10 cm. The light source wavelength range was 420-780 nm (visible light), and the system operated in a constant current mode with current densities of 1, 3, 5, and 10 mA / cm², respectively. 2 Using simulated wastewater containing 20 mg / L of 2,4,6-trichlorophenol as the target water body, repeated degradation tests were conducted. Each reaction lasted 30 minutes, with effluent samples collected every 10 minutes. The collected effluent was filtered through a 0.22 μm water membrane, and 2 mL was collected and placed in a liquid chromatography vial for testing degradation performance. This degradation test was repeated 10 times. After the reaction was complete, another 10 mL of the effluent was collected, filtered through a 0.22 μm water membrane, and used as the TOC test sample.

[0034] The concentration of 2,4,6-trichlorophenol was determined by ultra-high performance liquid chromatography (UHPLC). The test results showed that the removal capacity of the system for the target pollutant increased with increasing current density, especially when the current density exceeded 5 mA / cm². 2 When the reaction time was 30 minutes, the removal rate of target pollutants in the effluent exceeded 99%. The MoSe2 QD / TiO2NTA-003-12 photoanode at 3 mA / cm²... 2 Under the given conditions, the removal rate of the target pollutant in the effluent was 99% after 30 minutes of reaction. The TOC removal rate of the MoSe2 QD / TiO2 NTA-003-12 photoanode effluent followed the same pattern as the removal of the target pollutant, with current densities of 1, 3, 5, and 10 mA / cm². 2The TOC removal rates were 36%, 55%, 61%, and 88%. The results of 10 repeated tests showed no significant decrease in the removal rates of the target pollutant and TOC. The test results indicate that the higher the current density of the MoSe2 QD / TiO2 NTA, the higher the removal rates of both the target pollutant and TOC.

[0035] Example 4

[0036] Degradation tests on different types of simulated pharmaceutical wastewater:

[0037] MoSe2 QD / TiO2 NTA-003-8, MoSe2 QD / TiO2 NTA-003-12, MoSe2 QD / TiO2 NTA-003-16, and MoSe2 QD / TiO2 NTA-003-24 were used as photoanodes, and titanium mesh was used as the cathode. The electrode spacing was 1 cm to construct a photoelectrocatalytic system. The distance between the light source and the photoanode was 10 cm. The light source wavelength range was 420-780 nm (visible light), and the system operated in a constant current mode with a current density of 10 mA / cm². 2 Degradation tests were conducted using simulated wastewater containing 20 mg / L of ciprofloxacin hydrochloride, sulfamethoxazole, and 5-fluorouracil as the target water body. The reaction time was 30 min, and the effluent was sampled every 10 min. Each sample was filtered through a 0.22 μm water membrane, and 2 mL was collected and placed in a liquid chromatography vial for testing degradation performance. After the reaction was complete, another 20 mL of the effluent was filtered through a 0.22 μm water membrane and used as the TOC test sample.

[0038] The concentrations of target pollutants were determined by ultra-high performance liquid chromatography (UHPLC). Test results showed that the photoanodes MoSe2 QD / TiO2 NTA-003-8, MoSe2 QD / TiO2 NTA-003-12, MoSe2 QD / TiO2 NTA-003-16, and MoSe2 QD / TiO2 NTA-003-24 all achieved removal rates of over 99% for ciprofloxacin hydrochloride, sulfamethoxazole, and 5-fluorouracil. Among them, the photoanode MoSe2 QD / TiO2 NTA-003-12 achieved TOC removal rates of 92%, 83%, and 76%, respectively. This indicates that these electrode materials exhibit high degradation and mineralization performance for typical pharmaceutical pollutants in pharmaceutical wastewater within the photoelectrocatalytic degradation system.

[0039] Example 5

[0040] Degradation tests on actual pharmaceutical wastewater:

[0041] A photoelectrocatalytic system was constructed using MoSe2 QD / TiO2 NTA-003 as the photoanode and a titanium mesh as the cathode, with an electrode spacing of 1 cm. The light source was 10 cm away from the photoanode, and the wavelength range of the light source was visible light (420-780 nm). The system operated in a constant current mode with a current density of 10 mA / cm². 2 Degradation tests were conducted using actual pharmaceutical wastewater effluent from biological units (COD values ​​of 300, 500, and 1000 mg / L) as target water bodies. The reaction time was 2 hours, and the effluent was sampled every 10 minutes. The sampled effluent was directly placed into 10 mL centrifuge tubes and collected uniformly for testing COD removal performance. In addition, the content of antibiotic resistance genes in the wastewater before and after the reaction was investigated.

[0042] The COD of the effluent was tested using the national standard method. Test results showed that the MoSe2 QD / TiO2 NTA-003 electrode achieved COD removal rates of 83%, 79%, and 81% for actual pharmaceutical wastewater, respectively. This indicates that the photoanode has high removal performance for typical drugs in actual pharmaceutical wastewater. Tests on the content of antibiotic resistance genes in the wastewater before and after the reaction showed that the photoanode achieved a 99% removal rate of antibiotic resistance genes in the wastewater, effectively reducing the potential harm to the ecological environment caused by wastewater discharge into natural water bodies.

[0043] The MoSe2 QD / TiO2 NTA-003-12-H2O prepared in Comparative Example 1 and the MoS2QD / TiO2 NTA photoanode materials prepared in Comparative Example 2 were used in Examples 2-5, respectively. The comparison results are as follows:

[0044] Electrochemical performance tests showed that neither MoSe2 QD / TiO2 NTA-003-12-H2O nor MoS2QD / TiO2 NTA exhibited a significant response to visible light; that is, no significant potential difference was observed in the electrode OCP test results before and after visible light irradiation. Meanwhile, EIS testing indicated that MoSe2 QD / TiO2 NTA had better conductivity than the comparative materials MoSe2 QD / TiO2 NTA-003-12-H2O and MoS2 QD / TiO2 NTA.

[0045] The degradation test results of typical simulated pharmaceutical wastewater using photoelectrocatalytic systems showed that, under the same operating conditions, MoSe2 QD / TiO2 NTA-003-12-H2O and MoS2 QD / TiO2 NTA effectively reduced the degradation rate of 2,4,6-trichlorophenol simulated wastewater at a concentration of 20 mg / L, with a degradation rate of 5 mA / cm². 2 At current density, the removal rates of target pollutants in the effluent after 30 minutes of reaction were only 59% and 44%, respectively.

[0046] The degradation test results of different types of simulated pharmaceutical wastewater showed that, under the same operating conditions, the removal rates of MoSe2QD / TiO2NTA-003-12-H2O and MoS2QD / TiO2NTA for simulated wastewater containing 20 mg / L ciprofloxacin hydrochloride, sulfamethoxazole, and 5-fluorouracil were 76% and 54%, 49% and 32%, and 39% and 34%, respectively.

[0047] The degradation test results of actual pharmaceutical wastewater showed that, under the same operating conditions, the COD removal rates of MoSe2 QD / TiO2NTA-003-12-H2O and MoS2 QD / TiO2 NTA on the effluent of the biological unit of actual pharmaceutical wastewater (COD of 300, 500, and 1000 mg / L) were 27% and 18%, 22% and 13%, and 14% and 8%, respectively.

[0048] The comparative test results above demonstrate that the solvothermal reaction can effectively regulate the interfacial structure between MoSe2 QD and the substrate, enhance the interaction between active sites and the substrate, and form a stable MoSe2 QD / TiO2NTA photoanode material. MoSe2 has a structure similar to molybdenum disulfide (MoS2), possessing advantages such as a narrow band gap, excellent mechanical properties, resistance to photocorrosion, moderate interlayer spacing, and large specific surface area. Since Se has metallic properties that enhance the conductivity of MoSe2 materials, it can effectively improve the carrier migration rate. Therefore, loading MoSe2 QD can effectively improve the spectral response range, conductivity, and carrier migration capability of the substrate.

Claims

1. A method for preparing a MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode, characterized in that, The steps are as follows: Step 1: Using an electro-etching method, prepare an electro-etching solution to prepare a titanium suboxide nanotube array electrode (TiO2 NTA) in situ on the surface of a flat titanium electrode plate; Step 2: Using TiO2 NTA as the substrate, elemental Se with reducing ability and sodium molybdate were selected as the reaction precursors, with a molar ratio of 3:1 to 2:

1. 1-Ethyl-3-methylimidazolium acetate ionic liquid was used as the reaction solvent, and the concentration of sodium molybdate was controlled at 0.01-0.1 mol / L. A solvothermal method was adopted, with a reaction temperature of 140-200℃ and a reaction time of 8-24 h. After the solvothermal reaction was completed, the electrode material was removed and annealed. The electrode was then subjected to electrochemical reduction treatment to obtain MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode MoSe2 QD / TiO2 NTA. The annealing conditions were: air atmosphere, reaction at 400℃ for 2 hours.

2. The preparation method according to claim 1, characterized in that, The preparation method of the electro-etching solution is as follows: Ethylene glycol, ammonium fluoride and water are mixed in a mass ratio of 90:5:5 and magnetically stirred until the ammonium fluoride dissolves to form the electro-etching solution.

3. The preparation method according to claim 1, characterized in that, The electrochemical reduction process is as follows: the annealed electrode is used as the cathode, the lead oxide electrode as the anode, and a 10% wt ammonium sulfate aqueous solution is used as the electrolyte, with a constant current of 3 mA / cm. 2 Electrochemical reduction for 2 min.

4. The application of a MoSe2 quantum dot-supported titanium suboxide nanotube array photoanode prepared according to any one of claims 1-3 in pharmaceutical wastewater treatment, characterized in that, An electrochemical reaction system was constructed using a MoSe2 QD / TiO2 NTA electrode as the photoanode and a titanium mesh as the cathode, with an electrode spacing of 1-2 cm. The distance between the light source and the photoanode was 5-12 cm. The system was operated in a constant current mode with a current density of 1-10 mA / cm². 2 To treat pharmaceutical wastewater.

5. The application according to claim 4, characterized in that, The light source is visible light with a wavelength range of 420-780 nm.

6. The application according to claim 4, characterized in that, A DC power supply is used.

7. The application according to claim 4, characterized in that, The pharmaceutical wastewater contains ciprofloxacin hydrochloride, sulfamethoxazole, 5-fluorouracil, and 2,4,6-trichlorophenol.

8. The application according to claim 4, characterized in that, The concentration of pharmaceutical wastewater is 100 μg / L-50 mg / L.

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