A photo-induced thermal catalytic-chemiluminescence method for detecting H2S
By employing a photo-induced thermocatalytic chemiluminescence method using Z-type heterojunction Ag3PO4/Ag/Bi4Ti3O12 semiconductor materials, the shortcomings of catalytic luminescence sensors in terms of sensitivity and stability were overcome, enabling efficient detection of hydrogen sulfide.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-28
- Publication Date
- 2026-04-07
AI Technical Summary
Existing catalytic luminescence gas sensors are insufficient in terms of sensitivity, accuracy, and stability, making it difficult to meet the high requirements of environmental monitoring and diagnostics.
Z-type heterojunction Ag3PO4/Ag/Bi4Ti3O12 semiconductor material is used as the sensing material. Combined with photo-induced and thermocatalytic technologies, photogenerated electron-hole pairs and thermal energy are used to promote catalytic oxidation reactions and enhance the chemiluminescence signal.
It achieves high sensitivity, selectivity and rapid response detection of hydrogen sulfide, and the sensor equipment is simple, free from background interference and has long-term stability.
Smart Images
Figure CN117007582B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of sensing technology, specifically relating to a method utilizing a Z-type heterojunction Ag3PO4 / Ag / Bi4Ti3O 12 A highly efficient analytical method for detecting hydrogen sulfide was established using semiconductors as sensing materials, based on photo-induced thermocatalysis and chemiluminescence. Background Technology
[0002] Catalytic luminescence (CTL), a type of chemiluminescence, is the emission of light produced by compounds during catalytic oxidation reactions at the gas-solid interface. Gas sensors based on this transduction principle are widely used for the detection and identification of toxic and harmful gases due to their advantages such as miniaturization, rapid response, high selectivity, and low cost, making significant contributions to solving environmental problems, quality monitoring, catalyst evaluation, and clinical diagnosis. However, in these application areas, there are increasingly higher requirements for analytical performance, such as sensitivity, accuracy, and stability.
[0003] To achieve high reaction efficiency and high-sensitivity detection, exploring molecular pre-activation techniques and developing highly active nanomaterials are two main strategies. For example, combining dielectric barrier discharge (CTL) technology, ultraviolet-assisted technology, and photocatalytic-assisted technology with CTL systems can activate analyte molecules or oxidants, improving the oxidation reactivity of gas molecules and enhancing detection performance. Meanwhile, catalysts, as sensing materials, play a crucial role in CTL systems; their composition, structure, and morphology significantly influence the catalytic reaction mechanism and efficiency. For instance, utilizing luminescent rare-earth ions (Eu)... 3+ and Tb 3+ Based on the unique properties of gas molecules, an energy transfer CTL system with a unique sensing mechanism was developed, enabling highly sensitive detection of gas molecules and rapid identification of similar compounds. Therefore, it is reasonable to believe that the effective combination of innovative CTL sensing systems and advanced sensing materials will undoubtedly be a powerful analytical strategy for improving the sensing performance of gas compound analysis.
[0004] Currently, Z-type heterojunctions have emerged as a novel photothermal catalyst due to their unique charge separation efficiency and transfer pathways. Noble metal particles, acting as electron transfer media, can effectively transfer and separate photogenerated charges, thus serving as potential thermal catalysts. Furthermore, the LSPR absorption of noble metal NPs enhances light utilization efficiency and induces the generation of hot electron-hole pairs, enabling them to recombine with photogenerated holes and electrons, achieving spatial separation of photoinduced charges. This characteristic can be fully utilized by the thermal reaction conditions of CTL systems. Considering the positive effect of heat on photoinduced charge transfer and the thermocatalytic activity of sensing materials, Z-type heterojunction semiconductors generate photoinduced electron-hole pairs through LED irradiation, and then utilize thermal energy to mitigate electron-hole pair recombination, thereby improving the material's electron transport capability. Based on this, advanced Z-type heterojunction photothermal catalysts and photoinduced strategies can be introduced into CTL systems to promote the catalytic oxidation process of target compounds and enhance CTL behavior.
[0005] This invention synthesizes a Z-type heterojunction catalyst Ag3PO4 / Ag / Bi4Ti3O 12 As a sensing material for CTL sensors, Ag3PO4 exhibits efficient visible light response. Its stability issues can be mitigated through heterojunction structures. Ag nanoparticles possess superior electron trapping capabilities and the SPR effect, which facilitates charge transfer and separation, as well as the generation of oxygen species. Bi4Ti3O4, a perovskite semiconductor with a suitable bandgap structure and good thermal stability, is selected as the optimal material. 12 A Z-type heterojunction semiconductor catalyst Ag3PO4 / Ag / Bi4Ti3O was constructed by bridging Ag nanoparticles with Ag3PO4. 12 By utilizing the unique electron transport pathway and enhanced electron separation and transfer capabilities of the synthesized material, a photoinduced thermocatalytic chemiluminescence analysis method was further invented. This invention not only fully integrates the material properties to design a novel and efficient photoinduced thermocatalytic chemiluminescence analysis method, but also provides a highly sensitive, highly selective, fast-response, and long-term stable sensing and analysis method for H2S detection. Summary of the Invention
[0006] This invention aims to provide a method based on Ag3PO4 / Ag / Bi4Ti3O 12 An analytical method for the photo-induced thermocatalytic chemiluminescence detection of hydrogen sulfide using nanomaterials.
[0007] The principle of this invention is: Ag3PO4 / Ag / Bi4Ti3O 12 As a Z-type heterojunction semiconductor material, when excited by LED light, electrons in its valence band transition to the conduction band, generating photogenerated electron-hole pairs. The unique electron transport path of the Z-type heterojunction allows electrons and holes to migrate between Bi4Ti3O4 and the conduction band. 12Accumulation on Ag3PO4 and the LSPR effect of Ag nanoparticles further inhibit the recombination of photogenerated electron-hole pairs. Thermal energy, besides serving as a catalytic oxidation condition, also plays a positive role in the separation of photogenerated electrons and holes. Therefore, by promoting electron transfer within the material and at the material interface, it can accelerate the catalytic oxidation process of chemically adsorbed hydrogen sulfide and oxygen on the material surface, thereby enhancing the catalytic luminescence signal of hydrogen sulfide. Quantitative analysis of hydrogen sulfide can be achieved based on the linear relationship between the CTL response signal and the compound concentration.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] The photoinduced-thermocatalytic-chemiluminescence sensing device utilized in this invention includes a photoinducing device, a sample introduction device, a reaction device, and a detection device: an LED bead with a power of 5 W and a wavelength of 365 nm serves as the photoinducing device; the main function of the sample introduction device is to introduce hydrogen sulfide gas into the carrier gas passage through a micro-syringe, which then drives the gas into the reaction device; a self-made quartz tube (100 mm × 10 mm) and a cylindrical ceramic heating rod coated with sensing material inserted therein provide the reaction site for gas catalytic oxidation as the reaction device; the luminescence signal generated by the reaction is monitored by a BPCL ultra-weak luminescence analyzer equipped with a photomultiplier tube; and data analysis and processing are performed by a computer.
[0010] The sensing material in this invention is a Z-type heterojunction Ag3PO4 / Ag / Bi4Ti3O 12 The catalyst, specifically synthesized using the following method: Bi4Ti3O 12 First, the solution was prepared using a sol-gel method and a hydrothermal method. Solution A consisted of 0.02 mol bismuth nitrate dissolved in 15 mL acetic acid, and solution B consisted of 0.15 mol tetrabutyl titanate dissolved in 15 mL ethylene glycol methyl ether. The solutions were stirred until homogeneous at room temperature. Solution B was slowly added to solution A, and stirring continued for 2 hours to obtain a homogeneous sol. Then, 10 mL of acetic acid and 10 mL of ethylene glycol methyl ether were added, and the mixture was heated to 80 °C. ° Heating at C for 8 h yielded a dry gel; 75 mL of 3 M NaOH solution was added to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene, and the mixture was heated at 200 °C. ° Bi₄Ti₃O₃ was obtained by hydrothermal treatment at C temperature for 12 h, followed by cooling, filtration, washing, and drying at room temperature. 12 Take 1.2 mmol Bi4Ti3O 12 Add 10 mL of Ag(NH3)2OH and stir for 30 min. Then add 20 mL of 1.65 mol / L glucose solution, separate, wash, and dry to further synthesize the Ag / Bi4Ti3O sample. 12 Take 0.8 mmol Ag / Bi4Ti3O 12Add 30 mL of Na₂HPO₄ solution and stir thoroughly. Then, add 15 mL of 0.03 mol / L AgNO₃ solution dropwise while stirring continuously. Separate, wash, and dry to obtain the final product Ag₃PO₄ / Ag / Bi₄Ti₃O₄. 12 .
[0011] The specific implementation conditions for the detection of hydrogen sulfide based on the photoinduced-thermocatalytic-chemiluminescence method are as follows: the LED light is controlled by a power switch to make it effective against Ag3PO4 / Ag / Bi4Ti3O4. 12 The sensing material was continuously irradiated and excited for 2 minutes. After the LED light source was turned off, hydrogen sulfide gas was injected into the air carrier gas passage at a flow rate of 150 mL / min using a micro-syringe. The carrier gas carried the hydrogen sulfide gas into the quartz reaction cell, which was then subjected to reaction at an operating temperature of 230°C. ° C Ag3PO4 / Ag / Bi4Ti3O 12 A catalytic oxidation reaction occurs on the surface of the sensing material, and the emission signal is captured by a BPCL ultra-weak emission analyzer equipped with a photomultiplier tube. The operating voltage of the photomultiplier tube is set to -800V, and the data integration time of the BPCL ultra-weak emission analyzer is 0.1 s. Finally, the computer processes the data to obtain the catalytic emission signal of hydrogen sulfide.
[0012] The beneficial effects of this invention are: It utilizes light-induced heterojunction materials to generate photogenerated electron-hole pairs, while thermal energy suppresses the recombination of these pairs and promotes electron transfer within the material and at the gas-solid interface. This, in turn, promotes the catalytic oxidation of chemically adsorbed oxygen and hydrogen sulfide molecules, thereby enhancing the catalytic luminescence signal. This method, combined with the unique properties of the material, constructs a photoinduced-thermocatalytic-chemiluminescence analysis method. Furthermore, it features simple equipment, no background interference, fast reaction speed, and the ability to achieve long-term stable detection. Attached Figure Description
[0013] Figure 1 Bi4Ti3O 12 Ag / Bi4Ti3O 12 and Ag3PO4 / Ag / Bi4Ti3O 12 XRD images of nanomaterials.
[0014] Figure 2 Ag3PO4 / Ag / Bi4Ti3O 12 SEM images of nanomaterials.
[0015] Figure 3 0.7 μg / mL hydrogen sulfide based on different light exposure durations for Ag3PO4 / Ag / Bi4Ti3O 12 CTL response of nanomaterials.
[0016] Figure 4With Ag3PO4 / Ag / Bi4Ti3O 12 The CTL response curves of the photoinduced-thermocatalytic-chemiluminescence analysis method for the sensing material to different concentrations of hydrogen sulfide are shown.
[0017] Figure 5 With Ag3PO4 / Ag / Bi4Ti3O 12 This represents the linear relationship between the concentration of hydrogen sulfide and the CTL signal in the photoinduced-thermocatalytic-chemiluminescence analysis method for sensing materials.
[0018] Figure 6 With Ag3PO4 / Ag / Bi4Ti3O 12 This method enables the selective detection of hydrogen sulfide and other interfering substances using a photoinduced-thermocatalytic-chemiluminescence analysis approach for sensing materials.
[0019] Figure 7 With Ag3PO4 / Ag / Bi4Ti3O 12 The CTL response of the photoinduced-thermocatalytic-chemiluminescent system of the sensing material to 6.58 μg / mL hydrogen sulfide over 14 days was determined. Detailed Implementation
[0020] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed explanations are given below.
[0021] Example 1: 0.02 mol Bi(NO3)3·5H2O was dissolved in 15 mL of acetic acid as solution A, and 0.15 mol Ti(C4H9O)4 was dissolved in 15 mL of ethylene glycol monomethyl ether as solution B. After stirring at room temperature, solution B was slowly added to solution A, and stirring was continued for 2 h to obtain a homogeneous sol. 10 mL of acetic acid and 10 mL of ethylene glycol monomethyl ether were added, and the solution was stirred at 80 °C. ° Heating at C for 8 h produces a dry gel. 75 mL of 3 M NaOH solution is added to a 100 mL stainless steel high-temperature reactor lined with polytetrafluoroethylene. The mixture is then heated to 200 °C. ° Hydrothermal treatment was performed at C for 12 h, followed by cooling, filtration, washing, and drying at room temperature to obtain Bi4Ti3O. 12 Take 1.2 mmol of the synthesized Bi₄Ti₃O₃. 12 Add 10 mL of Ag(NH3)2OH and stir for 30 min, then add 20 mL of 1.65 mol L⁻¹. -1 Glucose solution, separation, washing, 80 ° Dry at C overnight, then further synthesize the Ag / Bi4Ti3O sample. 12 Take 0.8 mmol of Ag / Bi4Ti3O 12Add the solution to 30 mL of Na₂HPO₄ solution while stirring thoroughly, then continuously add 15 mL of 0.03 mol / L solution dropwise while stirring. -1 AgNO3 solution. Wash, dry, separate, and at 80°C. ° Drying at C for 8 h yields the nanomaterial Ag3PO4 / Ag / Bi4Ti3O for photoinduced thermocatalytic detection of hydrogen sulfide. 12 Bi4Ti3O 12 Ag / Bi4Ti3O 12 and Ag3PO4 / Ag / Bi4Ti3O 12 The crystal structure is obtained through Figure 1 The XRD pattern shows that Ag3PO4 / Ag / Bi4Ti3O 12 Composed of cubic Ag3PO4 (PDF# 06-0505), Ag (PDF# 04-0738), and orthogonal Bi4Ti3O 12 (PDF# 47-0398) Composition: Ag3PO4 / Ag / Bi4Ti3O 12 SEM images of the sensing nanomaterials are attached. Figure 2 As shown in AB, the hollow microspheres formed by the stacking of sheet-like structures have a diameter of approximately 2 μm.
[0022] Example 2: The air carrier gas flow rate was 150 mL / min, and the catalytic oxidation temperature was 230 °C. ° Under operating conditions C, the sensing material was continuously irradiated with a 365 nm LED for 0 min, 0.5 min, 1 min, 1.5 min, 2 min, 2.5 min, and 3 min. The CTL signal of H2S was detected under a 400 nm filter, as shown in the attached figure. Figure 3 As shown, the CTL signal gradually increases with increasing irradiation time, and gradually stabilizes after 2 min. It is 3 times higher than the CTL signal of hydrogen sulfide on the sensing material without light excitation, indicating that the photoinduced-thermal catalytic chemiluminescence analysis method effectively enhances the catalytic luminescence signal of hydrogen sulfide, and the enhancement level is affected by the photoinduction time.
[0023] Example 3: At an air carrier gas flow rate of 150 mL / min and a catalytic oxidation temperature of 230 °C... ° Under operating conditions C, hydrogen sulfide at concentrations of 0.095 μg / mL, 0.15 μg / mL, 0.35 μg / mL, 0.75 μg / mL, 2.08 μg / mL, 6.58 μg / mL, and 8.87 μg / mL was injected into the sensor device, and CTL response signals for different concentrations of hydrogen sulfide were obtained as follows: Figure 4 The linear relationship is shown in the appendix. Figure 5The linear equation is I = 11431.38C + 151.04, and the correlation coefficient R0 is... 2 =0.993, and the detection limit of hydrogen sulfide is calculated to be 0.0065 μg / mL.
[0024] Example 4: Based on the analytical method of the present invention, hydrogen sulfide (0.75 μg / mL), carbon disulfide (100 μg / mL), carbon monoxide, acetone, butanone, diethyl ether, acetaldehyde, ammonia, and benzene were detected, ensuring that the testing conditions were exactly the same. The CTL response signal results are shown in the appendix. Figure 6 As shown, apart from hydrogen sulfide, which can produce a strong CTL signal, the other compounds cannot produce a significant CTL signal, proving that the present invention has a high selectivity for detecting hydrogen sulfide.
[0025] Example 5: Using Ag3PO4 / Ag / Bi4Ti3O 12 The photoinduced thermocatalytic chemiluminescence (CTL) method for detecting hydrogen sulfide in the sensing material requires multiple injections of hydrogen sulfide. After the analytical performance test, the long-term stability of the sensing material was investigated. For the next 14 days, 6.58 μg / mL hydrogen sulfide was injected repeatedly every other day. The obtained CTL signals are shown below. Figure 7 As shown, this demonstrates that the photoinduced-thermocatalytic-chemiluminescent gas sensor exhibits long-term stability in both H2S sensing and the sensing material. Furthermore, the Ag3PO4 / Ag / Bi4Ti3O ... 12 It is a promising recyclable catalyst.
Claims
1. An analytical method for detecting hydrogen sulfide, characterized in that: (1) Ag3PO4 / Ag / Bi4Ti3O 12 The catalytic luminescent material was prepared as follows: It was prepared using bismuth nitrate, tetrabutyl titanate, silver ammonia solution, disodium hydrogen phosphate, and silver nitrate as raw materials. The specific synthesis process was as follows: 0.02 mol of bismuth nitrate was dissolved in 15 mL of acetic acid as solution A, and 0.15 mol of tetrabutyl titanate was dissolved in 15 mL of ethylene glycol methyl ether as solution B. The mixture was stirred at room temperature. Solution B was slowly added to solution A and stirred continuously for 2 h to obtain a uniform sol. Then, 10 mL of acetic acid and 10 mL of ethylene glycol methyl ether were added, and the mixture was heated at 80°C for 8 h to obtain a dry gel. 75 mL of 3 M NaOH solution was added to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene, and the mixture was hydrothermally treated at 200°C for 12 h. After cooling, filtration, washing, and drying at room temperature, Bi4Ti3O was obtained. 12 ; 1.2 mmol Bi4Ti3O 12 Add 10 mL of Ag(NH3)2OH and stir for 30 min. Then add 20 mL of 1.65 mol / L glucose solution, separate, wash, and dry to further synthesize the Ag / Bi4Ti3O sample. 12 Take 0.8 mmol Ag / Bi4Ti3O 12 Add 30 mL of Na2HPO4 solution and stir thoroughly. Then, add 15 mL of 0.03 mol / L AgNO3 solution dropwise while stirring continuously. Separate, wash, and dry to obtain the product Ag3PO4 / Ag / Bi4Ti3O. 12 The synthesized Ag3PO4 / Ag / Bi4Ti3O 12 It is a Z-type heterojunction semiconductor, which is a hollow sphere nanomaterial formed by stacking sheet structures. The diameter of the hollow sphere nanomaterial is 1.5~2.5 μm; (2) Its analytical method for detecting hydrogen sulfide is as follows: using 365 nm LED beads to continuously detect Ag3PO4 / Ag / Bi4Ti3O 12 After 2 minutes of catalytic sensing material, photogenerated electron-hole pairs are generated. After the lights are turned off, the catalytic temperature of 230°C continues to provide thermal energy to suppress the recombination of electron-hole pairs inside the material, promote the electron transfer of chemically adsorbed hydrogen sulfide and oxygen based on the material surface, and thus promote their catalytic oxidation process, thereby enhancing the CTL signal of hydrogen sulfide.
2. The analytical method according to claim 1, characterized in that: Ag3PO4 / Ag / Bi4Ti3O 12 As a catalytic sensing material, it is used in catalytic luminescence sensing devices, mainly including: (1) using LED beads with a power of 5 W and a wavelength of 365 nm as the light induction device for sensing material; (2) using a micro-syringe as the injection device to allow hydrogen sulfide to enter the catalytic luminescence reaction cell along with the carrier gas path; (3) using an insulating ceramic rod placed in a quartz tube as the reaction device, with the sensing material coated on the ceramic rod and the working temperature controlled by voltage; (4) using an ultra-weak luminescence analyzer equipped with a photomultiplier tube as the detection device to capture the luminescence signal; (5) using a computer as the data processing device to obtain the CTL response signal of hydrogen sulfide, and the quantitative detection of hydrogen sulfide is obtained by performing linear regression analysis on the signal.
3. The analytical method according to claim 1, characterized in that: The LED beads have a wavelength of 365 nm and a power of 5 W; the photomultiplier tube operates at -800V; the data integration time of the BPCL ultra-low luminescence analyzer is 0.1 s; air is used as the carrier gas with a flow rate of 150 mL / min; the operating temperature of the insulating ceramic rod is 230°C. ° C; The detection range of hydrogen sulfide is 0.095-8.87 μg / mL, and the detection limit is 0.00065 μg / mL.