Covalent organic framework material, preparation method and application of covalent organic framework material in hydrogen production by photocatalytic decomposition of hydrogen sulfide
By using covalent organic framework materials and Pt nanoparticles as photocatalysts to decompose hydrogen sulfide in alkaline solution to produce hydrogen, the problems of poor stability and low efficiency of inorganic metal materials were solved, and efficient and economical green energy production was achieved.
Patent Information
- Application Number
- CN202510743683.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-05
- Publication Date
- 2025-09-16
AI Technical Summary
Existing inorganic metal materials are easily poisoned during the photocatalytic decomposition of hydrogen sulfide to produce hydrogen, have poor stability, and are inefficient. In addition, traditional catalysts are expensive, making it difficult to achieve effective production of green energy.
Covalent organic framework materials are used as photocatalysts to photocatalytically decompose hydrogen sulfide in alkaline solutions. The stability and adjustable pore structure of covalent organic framework materials are utilized, combined with Pt nanoparticles as co-catalysts to achieve efficient decomposition of hydrogen sulfide to produce hydrogen.
It achieves efficient and stable decomposition of hydrogen sulfide to generate green energy hydrogen, reduces catalyst costs, and has good cycle stability and hydrogen production performance.
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Figure CN120647865A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of two-dimensional covalent organic framework photocatalysis, and in particular to a covalent organic framework material, a preparation method and its application in photocatalytic decomposition of hydrogen sulfide to produce hydrogen. Background Art
[0002] Hydrogen sulfide is a flammable and explosive gas with a recognized pungent odor, and it poses a significant risk to the human body. Hydrogen sulfide is ubiquitous in nature and various industrial scenarios, making the development of green hydrogen sulfide decomposition technologies crucial. Compared to traditional hydrogen sulfide decomposition technologies such as thermal decomposition and electrolysis, photocatalytic technology offers the advantage of being more environmentally friendly and eliminating the consumption of additional electricity, heat, and other energy sources. Furthermore, the hydrogen produced by decomposition can be recycled as a green energy source. Therefore, the process of decomposing hydrogen sulfide to produce hydrogen not only promotes the production of green hydrogen, but also removes the harmful gas hydrogen sulfide, aligning with the principles of green development and possessing significant practical significance.
[0003] Currently, the catalyst materials used for photocatalytic decomposition of hydrogen sulfide to produce hydrogen are all inorganic metal materials, but their practical application still faces huge challenges. The reasons are: (1) Hydrogen sulfide easily reacts with inorganic metal materials to poison them; (2) The oxidation products produced during the photocatalytic decomposition of hydrogen sulfide to produce hydrogen easily combine with inorganic metal materials to poison them, resulting in poor catalyst stability; (3) The efficiency of inorganic metal materials used for photocatalytic decomposition of hydrogen sulfide to produce hydrogen is generally not high. Compared with inorganic metal materials, organic materials are more stable.
[0004] Covalent organic frameworks (COFs) are a new type of crystalline porous polymer semiconductor material. They are formed by polymerizing covalently linked organic units composed of light elements into a highly ordered structure. They are easy to prepare, modify, and modify, allowing them to manipulate the optical properties and electronic structure of semiconductors. They also possess high porosity, adjustable pore size, an ordered pore structure, a large surface area, and excellent stability. Compared to traditional inorganic metal materials, COFs offer the advantages of ease of functionalization and a stable conjugated framework as photocatalytic materials, leading to their widespread application in photocatalysis. However, no organic materials have yet been studied for the photocatalytic decomposition of hydrogen sulfide to produce hydrogen. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a covalent organic framework material, a preparation method and a method for photocatalytically decomposing hydrogen sulfide in an alkaline solution. The present invention uses a covalent organic framework material for photocatalytically decomposing hydrogen sulfide to produce hydrogen, filling the technical gap in the use of organic materials for photocatalytically decomposing hydrogen sulfide to produce hydrogen.
[0006] The purpose of the present invention is to provide a method for preparing a covalent organic framework material, wherein the preparation of the material comprises the following steps:
[0007] (1) Adding organic monomer 1 and organic monomer 2 into a glass tube, followed by adding an organic solvent and a reaction catalyst, and uniformly dispersing them by ultrasonication;
[0008] (2) Freeze and thaw three times to remove all oxygen and other small gas molecules in the glass tube;
[0009] (3) Seal the glass tube under vacuum and then place it in a 90-120°C oven for 3-4 days;
[0010] (4) After the reaction is completed, the glass tube is opened, filtered, and rinsed with an organic solvent to obtain a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen.
[0011] Furthermore, the reaction formula for preparing the covalent organic framework material is as follows:
[0012]
[0013] Optionally, the organic monomer 1 is selected from the following structural formulas, one of which is selected:
[0014]
[0015] The organic monomer 2 is selected from the following structural formulas, one of which is selected:
[0016]
[0017] Optionally, in step (1) of the present invention, the organic monomer 1 is added at 0.1-1000 mmol, the organic monomer 2 is added at 0.1-1000 mmol, and the feed ratio of the organic monomer 1 to the organic monomer 2 is 2:3-1; the organic solvent is one or a combination of 1,4-dioxane, mesitylene, o-dichlorobenzene, n-butanol, acetonitrile, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, and acetone; and the reaction catalyst is one or a combination of acetic acid, pyrrolidine, trifluoroacetic acid, benzoic acid, imidazole, triethylamine, and propionic acid.
[0018] Optionally, in step (4) of the present invention, the organic solvent used for filtration is one or a combination of tetrahydrofuran, methanol, ethanol, acetone, N,N-dimethylacetamide, and dichloromethane.
[0019] The covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen is prepared by the above method. The covalent organic framework material is simple to prepare, has a stable structure, and has excellent photocatalytic performance.
[0020] The present invention also provides the use of the aforementioned covalent organic framework material for the photocatalytic production of hydrogen and the photocatalytic decomposition of hydrogen sulfide in an alkaline solution reaction medium. The photocatalytic reaction medium used for the photocatalytic decomposition of hydrogen sulfide to produce hydrogen is an alkaline solution that absorbs hydrogen sulfide gas to saturation; the alkaline solution specifically contains one or more of sulfites, bisulfites, sulfates, metal sulfides, metal bases, carbonates, and bicarbonates.
[0021] It should be noted that the present invention uses an alkaline solution as a photocatalytic reaction medium, which has the following advantages: (1) the reaction medium commonly used for photocatalytic hydrogen production using covalent organic framework materials is ascorbic acid, lactic acid, etc., which are expensive and not economically efficient; (2) the alkaline solution is conducive to more hydrogen sulfide entering the reaction system, thereby being decomposed to remove more harmful gases. In addition, it can also lower the pH of the reaction medium to promote the hydrogen evolution reaction to obtain more green energy hydrogen.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] (1) The present invention fills the technical gap in the photocatalytic decomposition of hydrogen sulfide by organic materials to produce hydrogen;
[0024] (2) The covalent organic framework material prepared by the present invention has a stable structure and produces hydrogen efficiently and stably, which can not only produce more green energy hydrogen, but also achieve the decomposition of harmful gas hydrogen sulfide;
[0025] (3) The photocatalytic reaction medium used in the present invention is an alkaline solution, which is lower in cost and has improved economic benefits compared to commonly used photocatalytic reaction media such as ascorbic acid;
[0026] (4) The present invention has universal applicability, and the monomers used to prepare the covalent organic framework materials are selective, the process is simple and efficient, the types of photocatalytic reaction media are selectable, and the application conditions are simple. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0028] Figure 1 This is an infrared spectrum of the covalent organic framework material TpTP-COF prepared in Example 1 of the present invention.
[0029] Figure 2 This is an X-ray diffraction data diagram of the covalent organic framework material TpTP-COF prepared in Example 1 of the present invention.
[0030] Figure 3 This is a graph showing the nitrogen isothermal adsorption-desorption curve data of the covalent organic framework material TpTP-COF prepared in Example 1 of the present invention.
[0031] Figure 4 This is the ultraviolet-visible absorption curve of the covalent organic framework material TpTP-COF prepared in Example 1 of the present invention.
[0032] Figure 5 This is the energy band structure diagram of the covalent organic framework material TpTP-COF prepared in Example 1 of the present invention.
[0033] Figure 6 The photocatalytic hydrogen production efficiency diagram (a) and cycle stability diagram (b) of the covalent organic framework material TpTP-COF in Example 1.
[0034] Figure 7 This is the hydrogen production efficiency diagram (a) and hydrogen production efficiency comparison diagram (b) of the photocatalytic decomposition of hydrogen sulfide by the covalent organic framework material TpTP-COF in Example 1. DETAILED DESCRIPTION
[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0036] The term "embodiment" is used herein specifically to describe any embodiment as "exemplary," and should not be construed as superior or preferable to other embodiments. Performance indicators in the embodiments of this application were tested using conventional testing methods in the art, unless otherwise specified. It should be understood that the terms used in this application are intended solely to describe specific implementations and are not intended to limit the disclosure herein.
[0037] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.
[0038] In order to better illustrate the content of this application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that this application can be implemented without certain specific details. In the examples, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of this application.
[0039] Under the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of this application.
[0040] The invention discloses a preparation method of a covalent organic framework material and application of the covalent organic framework material in producing hydrogen by photocatalytic decomposition of hydrogen sulfide.
[0041] In order to further understand the present invention, the porous microspheres and the preparation method thereof provided by the present invention are described in detail below with reference to examples. The protection scope of the present invention is not limited by the following examples.
[0042] Example 1, Preparation of TpTP-COF:
[0043] 1,3,5-trialdehyde phloroglucinol (0.3 mmol) and 4,4'-diaminoterphenyl (0.45 mmol) were added to a glass tube, followed by the addition of 4.5 mL of o-dichlorobenzene and 0.5 mL of n-butanol, and the mixture was dispersed evenly by ultrasonication for 5-10 minutes, and then 0.25 mL of pyrrolidine was added to obtain a reaction system containing monomers; the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for 10-20 minutes for degassing; then the glass tube was taken out and placed in ethanol for 5-15 minutes until the reaction system was completely melted; then the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for degassing, and this process was repeated three times to remove oxygen and other gases from the glass tube. After the reaction system in the glass tube is completely melted, the glass tube is placed in liquid nitrogen for freezing and sealed under vacuum; the glass tube is then placed in a 120°C oven for reaction for 3 days; after the reaction is completed, the glass tube is taken out of the oven, opened, filtered and rinsed with tetrahydrofuran and acetone in sequence to obtain a solid; the solid is then placed in a Soxhlet extractor filled with tetrahydrofuran solvent for Soxhlet extraction for 1 day, and the solid product is taken out after the extraction solvent in the Soxhlet extractor becomes transparent and clear; the solid product is placed in a 40°C vacuum oven and dried for 1 day, and then taken out to obtain the covalent organic framework material TpTP-COF.
[0044] The infrared spectrum data of the obtained material TpTP-COF is shown in Figure 1 , 1618cm -1 and 1254cm -1 The peaks at are attributed to the stretching vibrations of C=O and CN bonds, respectively, indicating that a keto-enamine bond is formed in Example 1, indicating that the covalent organic framework has been successfully prepared; the powder X-ray diffraction data of the obtained material TpTP-COF are shown in Figure 2 , indicating that Example 1 has good crystallinity, which is conducive to photocatalytic hydrogen production; the nitrogen isothermal adsorption-desorption curve data of the obtained material TpTP-COF are shown in Figure 3 , indicating that Example 1 has a larger specific surface area, and the calculated specific surface area is 762m 2 / g; The UV-visible absorption curve of the obtained material TpTP-COF is shown in Figure 4 , indicating that Example 1 can absorb most of the visible light and ultraviolet light; the band structure of the obtained material TpTP-COF is shown in Figure 5 The conduction band potential (CB) of Example 1 is -0.33 V (vs. RHE), the valence band potential (VB) is 1.91 V (vs. RHE), and the optical band gap is 2.24 eV, which meet the thermodynamic requirements of photocatalytic decomposition of hydrogen sulfide to produce hydrogen.
[0045] Example 2, Preparation of TpQP-COF:
[0046] 1,3,5-trialdehyde phloroglucinol (0.3 mmol) and 4,4'-diaminoquaternaryl (0.45 mmol) were added to a glass tube, followed by the addition of 2.5 mL of o-dichlorobenzene and 2.5 mL of n-butanol, and the mixture was dispersed evenly by ultrasonication for 5-10 minutes, and then 0.5 mL of trifluoroacetic acid was added to obtain a reaction system containing monomers; the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for 10-20 minutes for degassing; then the glass tube was taken out and placed in ethanol for 5-15 minutes until the reaction system was completely melted; then the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for degassing, and this process was repeated three times to remove oxygen and other gases from the glass tube. After the reaction system in the glass tube is completely melted, the glass tube is placed in liquid nitrogen for freezing and sealed under vacuum; the glass tube is then placed in a 120°C oven for reaction for 3 days; after the reaction is completed, the glass tube is taken out of the oven, opened, filtered and rinsed with methanol, ethanol and dichloromethane in sequence to obtain a solid; the solid is then placed in a Soxhlet extractor filled with methanol solvent for Soxhlet extraction for 1 day, and the solid product is taken out after the extraction solvent in the Soxhlet extractor becomes transparent and clear; the solid product is placed in a 40°C vacuum oven and dried for 1 day, and then taken out to obtain the covalent organic framework material TpQP-COF.
[0047] Example 3, Preparation of TpBT-COF:
[0048] 1,3,5-trialdehyde phloroglucinol (0.3 mmol) and 4,4'-(butane-1,3-diyne-1,4-diyl)diphenylamine (0.45 mmol) were added to a glass tube, followed by the addition of 4.75 mL of o-dichlorobenzene and 0.25 mL of n-butanol, and the mixture was dispersed evenly by ultrasonication for 5-10 minutes, and then 0.25 mL of pyrrolidine was added to obtain a reaction system containing monomers; the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for 10-20 minutes for degassing; then the glass tube was taken out and placed in ethanol for 5-15 minutes until the reaction system was completely melted; then the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for degassing, and this process was repeated three times to make the glass tube All oxygen and other small gas molecules in the tube are removed; after the reaction system in the glass tube is completely melted, the glass tube is placed in liquid nitrogen for freezing and sealed under vacuum; the glass tube is then placed in a 120°C oven for reaction for 3 days; after the reaction is completed, the glass tube is taken out of the oven, opened, filtered and rinsed with tetrahydrofuran and acetone in sequence to obtain a solid; the solid is then placed in a Soxhlet extractor filled with tetrahydrofuran solvent for Soxhlet extraction for 1 day, and the solid product is taken out after the extraction solvent in the Soxhlet extractor becomes transparent and clear; the solid product is placed in a 40°C vacuum oven and dried for 1 day to obtain the covalent organic framework material TpBT-COF.
[0049] Example 4, Preparation of TpID-COF:
[0050] 1,3,5-trialdehyde phloroglucinol (0.3 mmol) and 4,4'-(1H-benzo[D]imidazole-4,7-diyl)diphenylamine (0.45 mmol) were added to a glass tube, followed by the addition of 3.25 mL of N,N-dimethylacetamide and 1.75 mL of mesitylene, and the mixture was dispersed evenly by ultrasonication for 5-10 minutes, and then 0.5 mL of 6M acetic acid was added to obtain a reaction system containing a monomer; the glass tube was placed in liquid nitrogen for freezing, and then vacuumed for 10-20 minutes for degassing; then the glass tube was taken out and placed in ethanol for 5-15 minutes until the reaction system was completely melted; then the mixture was placed in liquid nitrogen for freezing, and then vacuumed for degassing, and this process was repeated three times. times, so that all oxygen and other gaseous small molecules in the glass tube are removed; after the reaction system in the glass tube is completely melted, the glass tube is placed in liquid nitrogen to freeze, and the glass tube is sealed under vacuum; the glass tube is then placed in a 120°C oven to react for 3 days; after the reaction is completed, the glass tube is taken out of the oven, opened, filtered, and rinsed with tetrahydrofuran and acetone in sequence to obtain a solid; the solid is then placed in a Soxhlet extractor filled with tetrahydrofuran solvent for Soxhlet extraction for 1 day, and the solid product is taken out after the extraction solvent in the Soxhlet extractor becomes transparent and clear; the solid product is placed in a 40°C vacuum oven and dried for 1 day, and then taken out to obtain the covalent organic framework material TpID-COF.
[0051] Application test example, a method for producing hydrogen by photocatalytic decomposition of hydrogen sulfide using a covalent organic framework material. This method is applicable to all covalent organic framework materials prepared by the present invention. Here, the material TpTP-COF prepared in Example 1 is taken as an example:
[0052] Photodeposition of co-catalyst Pt: Weigh 10 mg of TpTP-COF powder, ultrasonically disperse it in 100 mL of 0.1 M ascorbic acid solution, load it into a photocatalytic reactor, add 3 wt % chloroplatinic acid, use a xenon lamp as the photocatalytic light source, use a cutoff filter ≥420 nm, and after 30 minutes of illumination, filter the reaction solution to obtain a covalent organic framework material with deposited Pt nanoparticles.
[0053] The TpTP-COF powder after depositing Pt nanoparticles was ultrasonically dispersed in 0.1M sodium sulfide and sodium sulfite solution, loaded into a photocatalytic reactor, and vacuumed for 20 minutes before starting the photocatalytic test. A xenon lamp was used as the photocatalytic light source, and a cutoff filter of ≥420nm was used. The hydrogen production performance of the material was analyzed by gas chromatography after each hour of illumination. The hydrogen production performance after five hours was shown in Figure 2. Figure 6 (a), in the 56-hour cycle test Figure 6 (b) shows that the initial hydrogen production performance can still be maintained, indicating that the prepared covalent organic framework material has excellent stability and has excellent hydrogen production performance in the photocatalytic reaction medium containing sulfite and sulfide solutions as alkaline conditions, which exceeds that of most organic semiconductor materials.
[0054] Prepare hydrogen sulfide gas: add 50 mL of 1.5 M sodium sulfide solution to a 100 mL flask, evacuate the flask, slowly add 10 mL of 49 wt% sulfuric acid solution to the solution, and collect the resulting hydrogen sulfide gas with a rubber balloon. Repeat the above operation 4 times to obtain sufficient hydrogen sulfide gas.
[0055] The TpTP-COF powder after depositing Pt nanoparticles was ultrasonically dispersed in a 0.1M sodium sulfide and sodium sulfite solution, loaded into a photocatalytic reactor, and vacuumed for 20 minutes. A hydrogen sulfide balloon was connected to maintain the hydrogen sulfide atmosphere, and the prepared hydrogen sulfide gas was introduced into the solution at a rate of 25 mL / min using a peristaltic pump. The process lasted for 6 hours until the pH remained unchanged. A xenon lamp was used as the photocatalytic light source, and a cutoff filter of ≥420 nm was used. The gas in the reactor was extracted with a micro syringe every 1 hour of illumination, and the hydrogen production performance of the material was analyzed by gas chromatograph. The hydrogen production performance after ten hours was shown in FIG. Figure 7 (a) After ten hours, it can still maintain good hydrogen production performance. For comparison, the above photocatalytic reaction medium is replaced with 0.1M ascorbic acid and 0.1M sodium sulfide and sodium sulfite solution, and the hydrogen production performance is shown in FIG. Figure 7(b) It can be seen that the hydrogen production performance of the photocatalytic reaction medium is greatly improved after the addition of hydrogen sulfide, and the hydrogen production performance in 0.1M sodium sulfide and sodium sulfite solutions is also better than that in 0.1M ascorbic acid.
[0056] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen, characterized in that: The specific steps include: (1) Adding organic monomer 1 and organic monomer 2 into a glass tube, followed by adding an organic solvent and a reaction catalyst, and uniformly dispersing them by ultrasonication; (2) Freeze and thaw three times to remove all oxygen and other small gas molecules in the glass tube; (3) The glass tube is sealed under vacuum and then placed in an oven for reaction; (4) After the reaction is completed, the glass tube is opened, filtered, and rinsed with an organic solvent to obtain the covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen.
2. The method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen according to claim 1, wherein: The reaction formula for preparing the covalent organic framework material is as follows:
3. The method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen according to claim 1 or 2, characterized in that: The organic monomer 1 is selected from the following structural formula: The organic monomer 2 is selected from the following structural formula:
4. The method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen according to claim 1 or 2, characterized in that: In step (1), the molar ratio of organic monomer 1 to organic monomer 2 is 2:3-1; the organic solvent is one or a combination of 1,4-dioxane, mesitylene, o-dichlorobenzene, n-butanol, acetonitrile, methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, and acetone; and the reaction catalyst is one or a combination of acetic acid, pyrrolidine, trifluoroacetic acid, benzoic acid, imidazole, triethylamine, and propionic acid.
5. The method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen according to claim 1, wherein: The reaction temperature in step (3) is 90-120° C., and the reaction time is 3-4 days.
6. The method for preparing a covalent organic framework material for photocatalytic decomposition of hydrogen sulfide to produce hydrogen according to claim 1, wherein: In step (4), the organic solvent used for filtration is one or a combination of tetrahydrofuran, methanol, ethanol, acetone, N,N-dimethylacetamide, and dichloromethane.
7. A covalent organic framework material obtained by the method according to any one of claims 1 to 6.
8. Use of the covalent organic framework material obtained by the method according to any one of claims 1 to 6, characterized in that: The covalent organic framework material is used for photocatalytically decomposing hydrogen sulfide to produce hydrogen.
9. The use according to claim 8, characterized in that The photocatalytic reaction medium used for photocatalytic decomposition of hydrogen sulfide to produce hydrogen is an alkaline solution, which absorbs hydrogen sulfide gas to saturation; the alkaline solution is a solution containing one or more of sulfites, bisulfites, sulfates, metal sulfides, metal bases, carbonates, and bicarbonates.