A method for removing uranium and organic matter from a body of water while generating electricity

Abstract

The application provides a method for removing uranium and organic matters in water body and generating electricity simultaneously, and particularly relates to the field of resourceful treatment of wastewater. The method comprises the following steps: placing an electrolyte solution containing a source of hexavalent uranium and organic matters in a photoelectrocatalytic reaction tank for light irradiation; the photoelectrocatalytic reaction tank uses tin sulfide nanosheet / carbon felt as a cathode, and uses titanium dioxide nanomaterial and a photovoltaic cell as a composite anode. The application utilizes the light anode to generate electron-hole pairs under light excitation, and the post-positioned photovoltaic cell generates a bias voltage under light excitation to drive the photo-generated electrons to transfer to the cathode and generate electricity, while improving the separation efficiency of the electrons and the holes. The soluble and easily migratory hexavalent uranium is quickly enriched by the tin sulfide nanosheet / carbon felt and is reduced to the non-migratory tetravalent uranium precipitate on the surface of the tin sulfide nanosheet / carbon felt by the photo-generated electrons and low-valence S. According to the test results, the highest removal rate of the method provided by the application to the organic matters and the uranium can reach more than 97%, and the maximum power density is 2.01 mW·cm ‑2 .

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of resourceful treatment of wastewater, and particularly relates to a method for removing uranium and organic matters in water bodies and simultaneously generating electricity. BACKGROUND

[0002] With the rapid development of industry, environmental pollution and resource shortage have become key problems restricting the realization of sustainable development of human beings. It is well known that organic wastewater contains huge chemical energy, and traditional treatment technologies only consider the removal performance and ignore the chemical energy, resulting in energy waste. Therefore, the current pollution control method should focus on energy conversion and utilization, and simultaneously realize pollution control and energy production, so as to promote the sustainable development of human society.

[0003] At present, photoelectrocatalytic reaction system as a method for simultaneously degrading organic matters and producing clean energy has attracted extensive attention of researchers. However, few organic pollutants exist alone in wastewater, and most of the organic pollutants coexist with heavy metals such as hexavalent uranium. Therefore, only considering the degradation of organic matters and ignoring the treatment of heavy metals such as hexavalent uranium, this kind of wastewater still causes serious threat to the ecological system. In the prior art, the treatment methods for hexavalent uranium wastewater such as adsorption method, solvent extraction method, evaporation method, chemical reduction method and photocatalytic technology all show good treatment performance, but few can simultaneously realize efficient reduction of uranium (U) and efficient degradation of organic matters, and convert chemical energy into clean energy. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a method for removing uranium and organic matters in water bodies and simultaneously generating electricity, so as to solve the problem that the prior art is difficult to simultaneously realize efficient removal of metals and organic matters and convert chemical energy in wastewater into clean energy.

[0005] In order to solve the above technical problems, the present application provides the following technical solutions:

[0006] The present application provides a method for removing uranium and organic matters in water bodies and simultaneously generating electricity, comprising the following steps:

[0007] placing an electrolyte solution containing a source of hexavalent uranium and organic matters in a single-chamber photoelectrocatalytic reaction tank for light irradiation; the single-chamber photoelectrocatalytic reaction tank uses tin sulfide nanosheets / carbon felt as a cathode, and uses titanium dioxide nanomaterials and a photovoltaic cell as a composite anode;

[0008] The light irradiation is performed by a xenon lamp or sunlight.

[0009] Preferably, the electrolyte in the electrolyte solution comprises one or more of sodium sulfate, potassium sulfate, magnesium sulfate and sodium chloride, and the concentration of the electrolyte is 0.05-1.0 mol / L.

[0010] Preferably, the preparation method of the tin sulfide nanosheet / carbon felt comprises the following steps:

[0011] dissolving a tin source and a sulfur source in water to obtain a mixed solution;

[0012] placing the carbon felt in the mixed solution to perform a hydrothermal reaction to obtain the tin sulfide nanosheet / carbon felt;

[0013] The molar ratio of the tin source and the sulfur source is 0.25-0.55:1.

[0014] Preferably, the tin source is SnCl4.

[0015] The sulfur source is one or more of thiourea, thioacetamide and L-cysteine.

[0016] Preferably, the temperature of the hydrothermal reaction is 150-170℃, and the time is 8-16h.

[0017] Preferably, the hexavalent uranium source is uranyl nitrate hexahydrate, uranyl acetate dihydrate or uranyl carbonate.

[0018] Preferably, the organic matter comprises one or more of an antibacterial agent, a herbicide, an antibiotic, an anti-inflammatory agent and a pesticide and an intermediate.

[0019] Preferably, the concentration of the hexavalent uranium source is 5-12mg / L.

[0020] The concentration of the organic matter is 5-12mg / L.

[0021] Preferably, the pH value of the electrolyte solution is 4.0-5.5.

[0022] Preferably, the time of the light irradiation is 50-3600min.

[0023] The present application provides a method for removing uranium and organic matter in water and simultaneously generating electricity, comprising the following steps: placing an electrolyte solution containing a hexavalent uranium source and an organic matter in a single-chamber photoelectrocatalytic reaction tank to perform light irradiation; the single-chamber photoelectrocatalytic reaction tank uses tin sulfide nanosheet / carbon felt as a cathode, and uses a titanium dioxide nanomaterial and a photovoltaic cell as a composite anode; the light irradiation condition is xenon lamp or sunlight. The present application utilizes the fact that the light anode generates electron-hole pairs when excited by light irradiation, and the photovoltaic cell generates a bias voltage when excited by light irradiation, which can drive the photo-generated electrons to transfer to the cathode and generate electricity, and at the same time improve the separation efficiency of the electrons and the holes, and the holes and their derivatives ·OH left in the anode can degrade the organic matter, break the organic matter and uranium (UO2 2+) complexation releases hexavalent uranium, which is then quickly enriched by the SnS2 nanosheet / carbon felt and reduced to the immobile tetravalent uranium precipitate on the surface of the SnS2 nanosheet / carbon felt by the photo-generated electrons and low-valence S; the SnS2 nanosheet / carbon felt has a selective adsorption effect on uranium, in which S acts as a Lewis base to reduce the Lewis acid UO2 2+ ions have a strong affinity and are prone to chemical complexation to form complexes, which reduces the activation barrier and makes them easy to be reduced by photo-generated electrons, and low-valence S can also directly reduce hexavalent uranium to tetravalent uranium.

[0024] UO2 2+ has a trans-dioxygen-encapsulated U-containing oxygen cation structure, and the electron transfer activation barrier is relatively high. Compared with the reduction of hydrogen production or other heavy metals such as Cr(VI) (Cr(VI) / Cr(III), 1.33V), the reduction of UO2 2+ ions is more difficult, and directly using the carbon felt in the existing photoelectrocatalytic system as a cathode may have problems such as low uranium removal effect and slow reaction rate, which affects the separation efficiency of electrons and holes and affects the degradation of organic matter. The present application uses a hydrothermal reaction to grow SnS2 nanosheets on the surface of the carbon felt, and the presence of SnS2 significantly enhances the electrical conductivity and interface charge transfer efficiency of the carbon felt, strengthens the electrocatalytic activity of the carbon felt, promotes the reduction of uranium and the degradation of organic matter, and has good stability and reusability.

[0025] Further, the present application optimizes the preparation method of the SnS2 nanosheet / carbon felt, adjusts the pH of the electrolyte solution, the concentration of the hexavalent uranium source and the organic matter, and the electrolyte concentration, and constructs an optimal single-chamber photoelectrocatalytic reaction system. The test results show that the method provided by the present application for removing uranium and organic matter from water and generating electricity at the same time has a removal effect of more than 97% on each organic matter and uranium, and the maximum output power is as high as 2.03mW·cm -2 , which can efficiently remove uranium and organic matter and generate electricity.

[0026] Compared with the prior art, the application has the advantages that: (1) a photoelectrocatalytic system capable of efficiently removing uranium and organic matter and generating electricity is constructed by using tin sulfide nanosheets / carbon felt with adsorption and reduction properties for uranium as a cathode; (2) the application has a triple function. Compared with the existing treatment methods such as adsorption and photocatalysis, which can only realize single or double function, the application can simultaneously efficiently remove uranium and organic matter and convert chemical energy in wastewater into electrical energy, and has higher application value; (3) the application can directly utilize sunlight without the need of additional energy. Compared with the adsorption method which needs additional power to make it stir uniformly, the application can directly utilize actual light without the need of additional energy to remove uranium and organic matter and generate electricity; (4) the application has a wide application range. The removal rate of different types of organic matter+uranium wastewater is all above 93.35%, and the maximum output power can be up to 2.01 mW·cm -2 ; (5) the photoelectrocatalytic system can be quickly disassembled and constructed, and uranium in wastewater can be recycled and enriched in time. Compared with the conventional powder adsorbent and photocatalyst which are difficult to recycle, the photoelectrocatalytic system provided by the application can be directly taken out for recycling. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 SEM diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0029] Figure 2 BET diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0030] Figure 3 Mapping diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0031] Figure 4 XPS diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0032] Figure 5 CV diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0033] Figure 6 EIS diagram of the prepared tin sulfide nanosheet / carbon felt material;

[0034] Figure 7The removal effect diagram (a) and the electricity generation performance diagram (b) of different organic matters and uranium by the single-chamber photoelectrocatalytic reaction cell constructed by the prepared tin sulfide nanosheet / carbon felt material. DETAILED DESCRIPTION

[0035] The application provides a method for removing uranium and organic matters in a water body and generating electricity simultaneously, which comprises the following steps:

[0036] An electrolyte solution containing a hexavalent uranium source and organic matters is subjected to light irradiation in a single-chamber photoelectrocatalytic reaction cell; the single-chamber photoelectrocatalytic reaction cell uses tin sulfide nanosheet / carbon felt as a cathode and uses a titanium dioxide nanomaterial and a photovoltaic cell as a composite anode.

[0037] The light irradiation is performed by using a xenon lamp or sunlight.

[0038] In the application, the raw materials and equipment used are all commercially available products well known in the art, unless otherwise specified.

[0039] In the application, the hexavalent uranium source is preferably uranyl nitrate hexahydrate, uranyl acetate dihydrate or uranyl carbonate, and more preferably uranyl nitrate hexahydrate. The concentration of the hexavalent uranium source is preferably 5-12 mg / L, and more preferably 8-10 mg / L. In the specific embodiment of the application, the concentration of the hexavalent uranium source is 10 mg / L.

[0040] In the application, the organic matters preferably include one or more of antibacterial agents, herbicides, antibiotics, anti-inflammatory agents and pesticides and intermediates. The antibacterial agent preferably includes a medium-acting sulfonamide, and more preferably sulfisoxazole; the antibiotic preferably includes a quinolone antibiotic or a tetracycline antibiotic, and more preferably ciprofloxacin or tetracycline hydrochloride; the herbicide preferably includes a triazine herbicide, and more preferably atrazine; the anti-inflammatory agent preferably includes a non-steroidal anti-inflammatory drug, and more preferably ibuprofen; and the pesticide and intermediate preferably includes a nitrophenol, and more preferably p-nitrophenol. In the application, the concentration of the organic matters is preferably 5-12 mg / L, and more preferably 8-10 mg / L. In the specific embodiment of the application, the concentration of the organic matters is 10 mg / L.

[0041] In the application, the electrolyte in the electrolyte solution preferably includes one or more of sodium sulfate, potassium sulfate, magnesium sulfate and sodium chloride, and more preferably sodium sulfate. The concentration of the electrolyte is preferably 0.05-1.0 mol / L, and more preferably 0.1-0.5 mol / L. In the specific embodiment of the application, the concentration of sodium sulfate is 0.05 mol / L, 0.1 mol / L or 0.5 mol / L.

[0042] In the present application, the pH value of the electrolyte solution containing the source of hexavalent uranium and the organic matter is preferably 4.0-5.5, more preferably 4.1-5.2, and further preferably 4.5-5.0. In the present application, the pH value adjusting solution preferably uses one or both of sulfuric acid and sodium hydroxide.

[0043] In the present application, the tin sulfide nanosheet / carbon felt comprises a carbon felt and tin sulfide nanosheets distributed on the surface of the carbon felt.

[0044] In the present application, the preparation method of the tin sulfide nanosheet / carbon felt preferably comprises:

[0045] dissolving a tin source and a sulfur source in water to obtain a mixed solution;

[0046] placing the carbon felt in the mixed solution to perform a hydrothermal reaction to obtain the tin sulfide nanosheet / carbon felt;

[0047] The molar ratio of the tin source to the sulfur source is 0.25-0.55:1.

[0048] In the present application, the tin source is preferably SnCl4, and the sulfur source is preferably one or more of thiourea, thioacetamide and L-cysteine, and more preferably thiourea. In the present application, the molar ratio of the tin source to the sulfur source is preferably 0.25-0.55:1, and more preferably 0.3-0.5:1. In the specific embodiments of the present application, the molar ratio of the tin source to the sulfur source is 0.4:1.

[0049] In the present application, the concentration of the tin source in the mixed solution is preferably 0.2-0.4 mol / L.

[0050] In the present application, the carbon felt is preferably pretreated before being placed in the mixed solution. The present application does not have special requirements for the pretreatment method, and a common treatment method in the art can be used. Specifically, the carbon felt is sequentially cleaned with ultrapure water and ethanol under ultrasonic wave and then dried.

[0051] The present application does not have special requirements for the size of the carbon felt. In the embodiments of the present application, the size of the carbon felt is preferably 2.0x5.0 cm 2 , and the mass is 0.6 g. In the present application, the amount of the mixed solution is preferably enough to completely immerse the carbon felt.

[0052] In the present application, the temperature of the hydrothermal reaction is preferably 150-170℃, and more preferably 155-165℃; and the time is preferably 8-16 h, and more preferably 10-13 h. During the hydrothermal reaction, the tin sulfide nanosheets grow on the surface of the carbon felt.

[0053] After the hydrothermal reaction is completed, the application preferably further comprises cooling the obtained hydrothermal reaction product to room temperature, and then washing with deionized water and ethanol respectively, and drying to obtain a tin sulfide nanosheet / carbon felt material.

[0054] In the application, the number of times of washing with deionized water and ethanol is preferably 2-3 times independently, and the drying temperature is preferably 60°C, and the time is preferably 12h.

[0055] In the application, the tin sulfide nanosheet / carbon felt has a selective adsorption effect on uranium, in which sulfur as a Lewis base has a strong affinity for the Lewis acid UO2 2+ ion, and is easy to form a complex through a chemical complexation reaction with UO2 2+ ion, thereby reducing the activation barrier of UO2 2+ ion and making it easy to be reduced by photo-generated electrons; at the same time, free S 2- can also directly undergo a redox reaction with UO2 2+ to reduce hexavalent uranium to UO2 in the form of a precipitate. In addition, tin sulfide significantly enhances the electrical conductivity and interfacial charge transfer efficiency of the carbon felt, strengthens the electrocatalytic activity of the carbon felt, promotes the reduction of uranium and the degradation of organic matter, and has good stability and reusability.

[0056] In the application, the photoelectrocatalytic reaction cell is preferably a single-chamber photoelectrocatalytic reaction cell. The photoelectrocatalytic reaction cell uses tin sulfide nanosheet / carbon felt as a cathode, and a titanium dioxide nanomaterial and a photovoltaic cell as a composite anode.

[0057] In the application, the titanium dioxide nanomaterial is preferably prepared by using a technique commonly used in the art. Specifically, a mixture containing 0.1 mL of tetrabutyl titanate (TBT) and 10 mL of ethanol is coated on FTO (2x4cm 2 ) at 3000rpm for about 30s, dried at 60°C for 30min, and then annealed at 450°C for 2h. Subsequently, 30mL of ultrapure water, 30mL of hydrochloric acid (37wt%) and 0.72mL of TBT are mixed to prepare a precursor solution. The homogenized precursor solution is transferred to an autoclave, and the prepared FTO substrate is placed at the bottom with the TiO2 seed layer facing down. After heating at 170°C for 6h, the autoclave is naturally cooled to room temperature, and the obtained TNR is calcined at 500°C for 2h.

[0058] In the application, the photovoltaic cell is preferably a silicone gel cell.

[0059] In the present application, the composite photo-anode is combined together by the way of superimposition of the two in front of each other, with the edges of the two bound by silicone rubber sealing strip, wherein the positive electrode of the silica gel battery is directly connected with the TNR.

[0060] In the present application, the composite photo-anode of the combination of the titanium dioxide nanomaterial and the photovoltaic cell, the titanium dioxide nanomaterial is excited by light, and under the excitation of short-wavelength light wave (<400nm), electron-hole pairs are generated, wherein the holes and their derivatives ·OH (hole h + In the present application, the composite photo-anode of the combination of the titanium dioxide nanomaterial and the photovoltaic cell, the titanium dioxide nanomaterial is excited by light, and under the excitation of short-wavelength light wave (<400nm), electron-hole pairs are generated, wherein the holes and their derivatives ·OH (hole h + →·OH+H + ) can degrade organic matter, thereby breaking the complexation of the organic matter and uranium to release hexavalent uranium, and then the bias voltage generated by the photovoltaic cell under the excitation of long-wavelength light wave (400nm-780nm) drives the photo-generated electrons to transfer to the cathode, reducing the hexavalent uranium enriched on the surface of the tin sulfide, and accompanied by power generation.

[0061] In the present application, the light is preferably xenon lamp or sunlight, the light time is preferably 50-3600min, more preferably 60-3000min; when the xenon lamp is used, the irradiation intensity of the light is preferably 85-120mW·cm -2 , more preferably 100mW·cm -2 , the xenon lamp is preferably used in combination with 1.5 filter (AM 1.5G), and the time is preferably 60min; when the sunlight is used, the time is preferably 3600min.

[0062] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the present application will be described clearly and completely below in combination with specific embodiments, and the described embodiments are only some of the embodiments of the present application, not all the embodiments. Any modification, equivalent replacement, improvement, etc. made to the embodiments of the present application according to the technical essence and general principles of the present application without creative labor shall be within the protection scope of the present application.

[0063] Preparation of tin sulfide nanosheet / carbon felt

[0064] Commercial carbon felt (2.0×5.0cm 2 ) was sequentially cleaned by ultrasonic cleaning with ultrapure water and ethanol, dried at 60℃ for 12h, and prepared for use.

[0065] 5.47 g (0.021 mol) tin tetrachloride and 3.9963 g (0.053 mol) thiourea were added to 70 mL of ultrapure water, dissolved and stirred evenly, and poured into a reaction vessel containing clean commercial carbon felt. The mixture was hydrothermally reacted at 160 °C for 12 h. After cooling to room temperature, the mixture was washed 2-3 times each with deionized water and ethanol, and dried at 60 °C for 12 h to obtain tin sulfide nanosheets / carbon felt material.

[0066] The obtained tin sulfide nanosheets / carbon felt materials were observed under a scanning electron microscope, and their surface structure was as follows: Figure 1 As shown, the surface of the carbon felt is rough and contains tufted material composed of nanosheets with an average length of 0.5 μm and an average width of 0.05 μm.

[0067] Figure 2 The BET plot shows the obtained tin sulfide nanosheets / carbon felt material. From... Figure 2 It can be seen that the obtained nanosheet structure effectively increases the specific surface area of ​​the original carbon felt, providing more active sites for the carbon felt material.

[0068] Mapping tests were performed on the obtained tin sulfide nanosheets / carbon felt materials, and the test results are as follows: Figure 3 As shown, tin sulfide in tin sulfide nanosheets / carbon felt materials is mainly composed of S and Sn.

[0069] XPS tests were performed on the obtained tin sulfide nanosheets / carbon felt material, and the test results are as follows: Figure 4 As shown. Analysis reveals that the obtained tin sulfide nanosheets / carbon felt material contains Sn. 4+ and S 2- This indicates that tin sulfide was successfully loaded onto the carbon felt surface.

[0070] CV scanning was performed on the original carbon felt and tin sulfide nanosheet / carbon felt materials, and the results are as follows: Figure 5 As shown, the current density on the CV curve of tin sulfide nanosheets / carbon felt is significantly increased compared to the original carbon felt.

[0071] Comparing the EIS results of the original carbon felt with those of tin sulfide nanosheets / carbon felt materials, from Figure 6 It is known that the radius of curvature of tin sulfide nanosheets / carbon felt is smaller than that of the original carbon felt, which indicates that the carbon felt supported by tin sulfide has lower resistance. This may be because the high conductivity of tin sulfide allows charge to be transferred rapidly through the substrate to the electrolyte, thus reducing the internal resistance of the entire electrochemical system. This further indicates that the tin sulfide nanosheets / carbon felt material has rapid charge transfer and good (photo)electrocatalytic performance.

[0072] Example 1

[0073] Tin sulfide nanosheets / carbon felt were used as the cathode, and titanium dioxide nanomaterials + photovoltaic cells were used as the composite photoanode. A mixed solution was prepared by mixing 0.568 g of sodium sulfate, 5 mL of 80 mg / L uranyl nitrate, and 5 mL of 80 mg / L tetracycline hydrochloride with 30 mL of water. The concentrations of sodium sulfate, uranyl nitrate, and tetracycline hydrochloride were 0.1 mol / L, 10 mg / L, and 10 mg / L, respectively. The initial pH of the mixed solution was adjusted to 5.03, and the solution was added to a reaction cell to construct a 3×4×5 cm single-chamber photoelectrocatalytic reaction cell. A xenon lamp (AM 1.5G) was turned on at room temperature, and the photoanode in the prepared reaction cell was placed facing the light source for 60 min to complete the removal of uranium and tetracycline hydrochloride while generating electricity. The test results of the removal rate of uranium and tetracycline hydrochloride and the maximum power density were collected and plotted in Table 1 below.

[0074] Example 2

[0075] Other conditions were the same as in Example 1, except that the amount of sodium sulfate added was adjusted to 0.284 g, resulting in a mixed solution containing 0.05 mol / L sodium sulfate. The test results are shown in Table 1.

[0076] Example 3

[0077] Other conditions were the same as in Example 1, except that the amount of sodium sulfate added was adjusted to 2.84 g, resulting in a mixed solution containing 0.5 mol / L sodium sulfate. The test results are shown in Table 1.

[0078] Table 1. Removal efficiency and power generation of uranium and tetracycline hydrochloride in Examples 1-3

[0079]

[0080] As shown in Table 1, the removal efficiency of uranium and tetracycline hydrochloride increases with increasing sodium sulfate concentration, and the maximum power density also increases. This is mainly because high sodium sulfate concentration reduces the internal resistance of the solution and enhances its conductivity. When the sodium sulfate concentration is 0.1 M, the removal rates of uranium and organic matter reach 99.99% and 97.53%, respectively, indicating that the pollutants are essentially removed, and the maximum power density reaches 2.01 mW·cm³. -2 As the sodium sulfate concentration continues to increase to 0.5M, its removal rate and power generation also increase, but considering the cost, a sodium sulfate concentration of 0.1M is chosen.

[0081] Example 4

[0082] Other conditions were the same as in Example 1, except that the initial pH of the mixed solution was adjusted to 4.15, and the test results are shown in Table 2.

[0083] Table 2 shows the removal efficiency and power generation of uranium and tetracycline hydrochloride in Examples 1 and 4.

[0084]

[0085] As shown in Table 2, when the initial pH of the solution was 4.15, the removal rates of uranium and organic matter were 90.09% and 94.65%, respectively; as the pH increased to 5.03, the removal rates of uranium and tetracycline hydrochloride increased by 99.99% and 97.53%, respectively. This may be because as the pH increases, H+... + As the concentration decreases, there will be less H+. + Uranium competes with uranium for photogenerated electrons, thus significantly increasing uranium removal efficiency. This increased uranium removal efficiency means more electrons are consumed, further enhancing electron-hole separation efficiency. More separated holes are available for degrading organic matter, thus increasing organic matter removal efficiency.

[0086] Example 5

[0087] Other conditions were the same as in Example 1, except that the initial concentration of tetracycline hydrochloride was adjusted to 5 mg / L. The test results are shown in Table 3.

[0088] Table 3 shows the removal efficiency and power generation of uranium and tetracycline hydrochloride in Examples 1 and 5.

[0089]

[0090] As shown in Table 3, when the concentration of tetracycline hydrochloride solution was reduced to 5 mg / L, the removal rates of uranium and tetracycline hydrochloride, as well as the power generation, remained at a high level. The removal rates of tetracycline hydrochloride and uranium reached 97.65% and 98.34%, respectively, and the maximum output power density reached 2.03 mW·cm³. -2 .

[0091] Example 6

[0092] Other conditions were the same as in Example 1, with the initial concentration of the uranium solution adjusted to 5 mg / L. The test results are shown in Table 4.

[0093] Table 4 shows the removal efficiency and power generation of uranium and tetracycline hydrochloride in Examples 1 and 6.

[0094]

[0095] As can be seen from Table 4, when the uranium solution concentration is reduced to 5 mg / L, the removal rates of uranium and tetracycline hydrochloride, as well as the power generation, remain at a high level.

[0096] Comparative Example 1

[0097] Other conditions were the same as in Example 1, except that the cathode of the single-chamber photoelectrocatalytic reaction cell was changed to a cleaned carbon felt. The test results are shown in Table 5.

[0098] Table 5. Removal efficiency and power generation of uranium and tetracycline hydrochloride in Example 1 and Comparative Example 1.

[0099]

[0100] As shown in Table 5, the single-chamber photoelectrocatalytic reactor constructed using cleaned commercial carbon felt as the cathode achieved removal efficiencies of 29.34% and 54.35% for uranium and tetracycline hydrochloride, respectively. These figures are significantly lower than the removal rates of uranium (99.99%) and tetracycline hydrochloride (97.53%) under the same conditions in Example 1, and the maximum output power density (1.11 mW·cm⁻¹) is also lower. -2 This is also far lower than the maximum output power density (2.01 mW·cm⁻¹) of a single-chamber photoelectrocatalytic reactor using tin sulfide nanosheets / carbon felt as the cathode. -2 This study confirmed that tin sulfide nanosheets / carbon felt enhance the electrocatalytic activity of the photoelectrocatalytic reaction system.

[0101] Comparative Example 2

[0102] The obtained tin sulfide nanosheets / carbon felt material was used as an adsorbent and added to a 40 mL mixed solution containing 0.568 g sodium sulfate (0.1 mol / L), 10 mg / L uranyl nitrate and 10 mg / L tetracycline hydrochloride. The pH was adjusted to 5.03, and adsorption was carried out for 60 min to complete the removal of uranium and tetracycline hydrochloride. The test results are shown in Table 6.

[0103] Comparative Example 3

[0104] Titanium dioxide nanomaterials were used as photocatalysts and added to a 40 mL solution containing 0.568 g sodium sulfate (0.1 mol / L), 10 mg / L uranyl nitrate, and 10 mg / L tetracycline hydrochloride. The pH was adjusted to 5.03, and the solution was irradiated at room temperature under a xenon lamp (AM1.5G) for 60 min to remove uranium and tetracycline hydrochloride. The test results are shown in Table 6.

[0105] Table 6. Results of removal rates of uranium and tetracycline hydrochloride in Examples 1 and Comparative Examples 2-3.

[0106]

[0107] Table 6 shows that when tin sulfide nanosheets / carbon felt are used alone as adsorbents, the removal rates of uranium and tetracycline hydrochloride are 47.66% and 51.60%, respectively, which are much lower than those of the photoelectrocatalytic system constructed using tin sulfide as the cathode. Furthermore, uranium is enriched on the material surface in hexavalent uranium or molecular form, posing a significant risk of migration. When titanium dioxide nanomaterials are used alone as photocatalysts, the removal rates of uranium and tetracycline hydrochloride are 19.00% and 8.05%, respectively, which are also much lower than those of the photoelectrocatalytic system constructed using titanium dioxide as the anode.

[0108] Application Example 1

[0109] Other conditions were the same as in Example 1, except that the xenon lamp in Example 1 was replaced with sunlight irradiation and the irradiation time was adjusted to 3600 min. The removal of uranium and tetracycline hydrochloride was completed while generating electricity. The test results are shown in Table 7.

[0110] Table 7. Removal efficiency and power generation of uranium and tetracycline hydrochloride in Example 1 and Application Example 1.

[0111]

[0112] As shown in Table 7, under actual illumination, the single-chamber photoelectrocatalytic reactor constructed using tin sulfide-modified carbon felt as the cathode achieved removal rates of 92.49% and 97.96% for uranium and tetracycline hydrochloride, respectively, with a maximum output power density of 44.78 mW·cm⁻¹. -2 Therefore, it can be seen that the method provided by the present invention can achieve efficient removal of uranium and tetracycline hydrochloride from water and generate electricity stably by relying solely on sunlight without consuming other energy sources.

[0113] Application Example 2

[0114] Other conditions were the same as in Example 1, except that tetracycline hydrochloride in Example 1 was replaced with p-nitrophenol, ciprofloxacin, atrazine, ibuprofen, or sulfamethoxazole. The test results are shown in 8.

[0115] Table 8. Removal efficiency and power generation of uranium and tetracycline hydrochloride in Example 1 and Application Example 2.

[0116]

[0117] Table 8 shows that the single-chamber photoelectrocatalytic reactor constructed using tin sulfide nanosheets / carbon felt as the cathode achieved a removal efficiency of over 93.35% for all organic compounds and uranium, with a maximum output power reaching 2.01 mW·cm⁻¹. -2 It can efficiently remove uranium and organic matter and generate electricity.

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing uranium and organic matter from water while simultaneously generating electricity, characterized in that, Includes the following steps: An electrolyte solution containing hexavalent uranium source and organic matter is placed in a single-chamber photoelectrocatalytic reaction cell for illumination; the single-chamber photoelectrocatalytic reaction cell uses tin sulfide nanosheets / carbon felt as the cathode and titanium dioxide nanomaterials and photovoltaic cells as the composite photoanode; The illumination conditions are xenon lamps or sunlight; The method for preparing the tin sulfide nanosheets / carbon felt includes: The tin source and sulfur source are dissolved in water to obtain a mixed solution; Carbon felt was placed in a mixed solution and subjected to a hydrothermal reaction to obtain tin sulfide nanosheets / carbon felt; the temperature of the hydrothermal reaction was 150–170 °C. The molar ratio of the tin source to the sulfur source is 0.25 to 0.55:

1.

2. The method according to claim 1, characterized in that, The electrolyte in the electrolyte solution includes one or more of sodium sulfate, potassium sulfate, magnesium sulfate and sodium chloride, and the concentration of the electrolyte is 0.05 to 1.0 mol / L.

3. The method according to claim 1, characterized in that, The tin source is SnCl4; the sulfur source is one or more of thiourea, thioacetamide and L-cysteine.

4. The method according to claim 1, characterized in that, The hydrothermal reaction takes 8 to 16 hours.

5. The method according to claim 1, characterized in that, The hexavalent uranium source is uranyl nitrate hexahydrate, uranyl acetate dihydrate, or uranyl carbonate.

6. The method according to claim 1, characterized in that, The organic matter includes one or more of antibacterial agents, herbicides, antibiotics, anti-inflammatory agents, pesticides, and intermediates.

7. The method according to claim 1 or 5, characterized in that, The concentration of the hexavalent uranium source is 5–12 mg / L; the concentration of the organic matter is 5–12 mg / L.

8. The method according to claim 1 or 2, characterized in that, The pH value of the electrolyte solution is 4.0 to 5.

5.

9. The method according to claim 1, characterized in that, The illumination time is 50–3600 min.

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