ZnIn2S4 / CoO / ATP ternary composite photocatalyst and preparation and application thereof
By constructing a ZnIn2S4/CoO/ATP ternary composite material on the surface of ATP nanorods, the problems of easy aggregation of ZnIn2S4 and high recombination rate of photogenerated carriers were solved, achieving efficient and stable photocatalytic water splitting for hydrogen production, with good cycle stability and economic benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF MINING & TECH
- Filing Date
- 2026-01-09
- Publication Date
- 2026-04-21
AI Technical Summary
Existing photocatalytic materials such as ZnIn2S4 are prone to aggregation, have high recombination rates of photogenerated carriers, and are difficult to recover, which limits their catalytic efficiency and stability.
By sequentially loading CoO nanoparticles and ZnIn2S4 nanosheets onto the surface of ATP nanorods, a ZnIn2S4/CoO/ATP ternary composite material was constructed. The carrier advantage and band synergy of ATP were utilized to inhibit the aggregation of active components and promote the separation and utilization of photogenerated charge carriers.
It significantly improves photocatalytic performance, increases hydrogen production rate and cycle stability, and the material is easy to recycle, with good mechanical stability and economic benefits.
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Figure CN121892166A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photocatalytic materials and their preparation technology, specifically to a ZnIn2S4 / CoO / ATP ternary composite photocatalyst based on attapulgite (ATP) and its preparation and application. Background Technology
[0002] As the global energy structure transitions towards a green and low-carbon model, the development of clean and renewable energy has become a crucial direction for technological innovation. Hydrogen energy, as an ideal zero-carbon energy carrier, requires breakthroughs in large-scale production technology for strategic significance in building a sustainable energy system. Solar-driven water splitting hydrogen production technology enables the direct conversion and storage of solar energy, with the development of high-performance photocatalytic materials being the core of this technology.
[0003] Against this backdrop, natural silicate minerals, due to their abundant reserves, low cost, and environmental friendliness, exhibit unique value in the field of photocatalysis. Attapulgite (ATP) clay, in particular, as a natural mineral with a one-dimensional nanorod structure and abundant surface functional groups, provides an ideal platform for the high-value utilization of functional materials. ATP's unique layered chain structure and tunable surface properties enable it to serve as an excellent carrier material, effectively dispersing and stabilizing active components and preventing nanoparticle aggregation. Simultaneously, its silicate framework provides a favorable pathway for charge transport. However, how to organically combine the carrier advantages of ATP with highly efficient photoactive components through rational structural design to construct composite photocatalysts with synergistic enhancement effects remains a topic that requires further exploration.
[0004] On the other hand, zinc indium sulfide (ZnIn2S4), as a typical visible-light-responsive semiconductor, has attracted widespread attention due to its suitable band structure and good photochemical stability. However, single ZnIn2S4 particles tend to spontaneously aggregate to form micron-sized flower-like structures during preparation, leading to a reduction in specific surface area and masking of active sites, thus limiting further improvements in its catalytic efficiency. Simultaneously, its inherently high photogenerated carrier recombination rate also restricts its practical applications.
[0005] To overcome the aforementioned limitations, constructing a multi-component heterojunction system is considered an effective strategy. Cobalt oxide (CoO), as a p-type semiconductor, possesses a wide visible light absorption range and suitable band structure, enabling effective band matching with n-type ZnIn2S4 and promoting the separation of photogenerated electron-hole pairs. Studies have shown that combining CoO nanoparticles with other semiconductors can significantly enhance photocatalytic performance; for example, Chu et al. reported that the CdS / CoO heterostructure achieved a hydrogen evolution rate 36 times higher than pure CdS [Nanoscale, 2019, 11(33): 15633-15640]. However, the tendency of CoO nanoparticles to aggregate still limits their activity.
[0006] Based on the above understanding, this invention, from the perspective of promoting the high-value utilization of natural mineral resources, constructs a hierarchical ZnIn2S4 / CoO / ATP ternary composite material by sequentially loading CoO nanoparticles and ZnIn2S4 nanosheets onto the surface of ATP nanorods through a rational structural design. This design not only fully utilizes the carrier advantages and structural characteristics of ATP to effectively inhibit the aggregation of active components, but also achieves efficient separation and utilization of photogenerated carriers through band synergy and interface effects among the three components, providing a new approach for developing efficient, stable, and easily recyclable photocatalytic hydrogen production materials. Summary of the Invention
[0007] To address the problems of easy aggregation, low charge separation efficiency, and difficult recovery of single photocatalytic materials in existing technologies, this invention provides a ZnIn2S4 / CoO / ATP ternary composite photocatalyst based on attapulgite (ATP), its preparation, and its application.
[0008] This invention is achieved through the following technical solution: This invention provides a ZnIn2S4 / CoO / ATP ternary composite photocatalyst, wherein the ZnIn2S4 / CoO / ATP ternary composite photocatalyst comprises a CoO / ATP composite material and a ZnIn2S4 nanosheet grown on the surface of the CoO / ATP composite material, wherein the mass ratio of ZnIn2S4 to CoO / ATP is 3:7.
[0009] This invention also provides a method for preparing a ZnIn2S4 / CoO / ATP ternary composite photocatalyst, characterized by comprising the following steps: Step 1: Disperse ATP in an acidic solution, stir the acidic solution containing ATP under heating conditions, centrifuge the reaction product after the reaction, wash until neutral, dry to obtain acid-modified ATP, and grind the acid-modified ATP into powder. Step 2: Add the acid-modified ATP powder obtained in Step 1 to the cobalt nitrate solution, disperse it by ultrasound and stir to mix. Slowly add urea solution to form a mixture. Stir the mixture under heating conditions to react. Wash, dry and calcine the reaction product to obtain the CoO / ATP composite material. Grind the CoO / ATP composite material into powder. Step 3: Disperse the CoO / ATP powder obtained in Step 2 in a solvent and stir to form a dispersion. Add zinc source, indium source and sulfur source to the dispersion in sequence and stir thoroughly. Transfer the stirred and mixed dispersion to a high-pressure reactor and carry out a hydrothermal reaction at a specific temperature. Cool the reaction dispersion, centrifuge, wash and dry to obtain the ZnIn2S4 / CoO / ATP ternary composite photocatalyst.
[0010] Preferably, the heating conditions in step one are 70~90℃, with an optimal temperature of 80℃; the heating conditions in step two are 100~130℃, with an optimal temperature of 115℃; the calcination temperature in step two is 350~450℃, with an optimal calcination temperature of 400℃, and the calcination time is 0.5~1.5 h, with an optimal calcination time of 1 h; the hydrothermal temperature in step three is 100~140℃, with an optimal temperature of 120℃, and the reaction time is 10~14 h, with an optimal reaction time of 12 h; and during the stirring process in steps one, two, and three, the stirring rate is 300~1500 r / min, with an optimal stirring rate of 600 r / min; the stirring time in step one is 9~11 h, with an optimal time of 10 h; the stirring time after ultrasonic dispersion in step two is 0.25~0.5 h, with an optimal time of 0.35 h, and the heating and stirring time is 1~2 h, with an optimal time of 1.5 h. h; the stirring time after adding each raw material in step three is 0.25~1 h, with the optimal time being 0.5 h.
[0011] Preferably, the acid solution in step one is a hydrochloric acid solution, the solvent in step three is a mixture of deionized water and ethylene glycol, the zinc source is zinc chloride, the indium source is indium trichloride tetrahydrate, and the sulfur source is thioacetamide.
[0012] Preferably, the concentration of the hydrochloric acid solution is 3 mol / L, the concentration of the cobalt nitrate solution is 0.032 mol / L, the concentration of the urea solution is 0.128 mol / L, and the volume ratio of deionized water to ethylene glycol is 5:1.
[0013] Preferably, the molar ratio of the zinc source, indium source and sulfur source is 1:2:4.
[0014] Preferably, in steps one, two, and three, the product is washed several times with alternating ethanol and distilled water after centrifugation; the drying is vacuum drying, with a drying time of 3-5 hours, the optimal drying time being 4 hours, and a drying temperature of 50-70°C, the optimal drying temperature being 60°C.
[0015] Preferably, the grinding in steps one and two is performed by mechanical grinding.
[0016] The second objective of this invention is to provide a ZnIn2S4 / CoO / ATP ternary composite photocatalyst prepared by the above-described method.
[0017] In addition, the present invention also provides an application of the above-mentioned ZnIn2S4 / CoO / ATP ternary composite photocatalyst in photocatalytic water splitting for hydrogen production.
[0018] 1. Unique structural design: CoO nanoparticles were first loaded in situ on the surface of ATP nanorods by solution impregnation-calcination, and then ZnIn2S4 nanosheets were grown on the CoO / ATP surface by hydrothermal method. A hierarchical ZnIn2S4 / CoO / ATP ternary composite photocatalyst was successfully constructed. This structure effectively utilizes the carrier properties of ATP, significantly inhibits the aggregation of CoO nanoparticles and ZnIn2S4 nanosheets, and exposes more active sites.
[0019] 2. Synergistic effect of components: ATP not only serves as a dispersing framework, but its interfacial synergistic effect with CoO and ZnIn2S4 effectively promotes the separation and migration of photogenerated carriers. The introduction of CoO expands the photoresponse range of the composite material, while ZnIn2S4 provides abundant catalytic active sites. The synergistic effect of the three significantly improves the photocatalytic performance.
[0020] 3. Significantly improved performance: Compared with single-component or binary composite materials, the ternary composite photocatalyst prepared in this invention exhibits a higher hydrogen production rate and better cycle stability in the photocatalytic water splitting hydrogen production reaction. This is mainly attributed to its optimized band structure, enhanced visible light absorption, and high space charge separation efficiency.
[0021] 4. The material is easy to recycle: Thanks to the inherent rigid framework structure of ATP nanorods, the prepared composite photocatalyst has good mechanical stability and is easy to separate and recover from the reaction system, and has good potential for practical application.
[0022] 5. High-value utilization of resources: This invention provides a new way to utilize natural attapulgite clay in a high-value manner. By constructing a high-efficiency composite photocatalyst, inexpensive mineral materials are applied to the cutting-edge field of photocatalytic hydrogen production, which has both economic and environmental benefits. Attached Figure Description
[0023] Figure 1 The X-ray diffraction patterns of Example 1 (ZnIn2S4 / CoO / ATP), Comparative Example 2 (CoO), Comparative Example 3 (acidified ATP), and Comparative Example 4 (ZnIn2S4) of the present invention are shown below. Figure 2 Example 1 of the present invention (ZnIn2S4 / CoO / ATP, Figure 2 d) The CoO / ATP complex in the preparation process of Example 1 ( Figure 2 c) Comparative Example 3 (Acidified ATP, Figure 2 b), and Comparative Example 4 (ZnIn2S4, Figure 2 a) Scanning electron microscope image; Figure 3 Example 1 of the present invention (ZnIn2S4 / CoO / ATP, Figure 3 d) The CoO / ATP complex in the preparation process of Example 1 ( Figure 3 c) Comparative Example 3 (Acidified ATP, Figure 3 b), and Comparative Example 4 (ZnIn2S4, Figure 3 Transmission electron microscope image of a); Figure 4 This is a high-angle annular dark-field scanning transmission electron microscope image of Example 1 (ZnIn2S4 / CoO / ATP) of the present invention; Figure 5 The ultraviolet-visible absorption spectra of Example 1 (ZnIn2S4 / CoO / ATP), Comparative Example 2 (CoO), Comparative Example 3 (acidified ATP), and Comparative Example 4 (ZnIn2S4) of the present invention are shown. Figure 6 The visible light photocatalytic hydrogen production performance of Example 1 (ZnIn2S4 / CoO / ATP), Comparative Example 1 (ZnIn2S4 / CoO), Comparative Example 2 (CoO), Comparative Example 3 (acidified ATP), and Comparative Example 4 (ZnIn2S4) are shown in the figure. Figure 7 The graph shows the stability test results of the photocatalytic hydrogen production cycle for Example 1 (ZnIn2S4 / CoO / ATP). Detailed Implementation
[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below.
[0025] This invention provides a ZnIn2S4 / CoO / ATP ternary composite photocatalyst, the preparation method of which is as follows: ATP was dispersed in an acidic solution and stirred under heating conditions. After the reaction, the mixture was centrifuged, washed until neutral, dried, and ground for later use. Acid-modified ATP was added to a cobalt nitrate solution, ultrasonically dispersed, and stirred. Urea solution was slowly added to form a mixture, which was then stirred under heating conditions. The product was washed, dried, and calcined to obtain a CoO / ATP composite material. The above powder was dispersed in a solvent and stirred to form a dispersion. Zinc and indium sources were added to the above solution and stirred evenly. Finally, a sulfur source was added and stirred thoroughly. The mixture was transferred to an autoclave and subjected to hydrothermal reaction at a specific temperature. After the reaction, the mixture was cooled, centrifuged, washed, and dried to obtain the ZnIn2S4 / CoO / ATP ternary composite photocatalyst.
[0026] It should be noted that the present invention first anchors ultrafine CoO nanoparticles onto the surface of ATP nanorods using a solution impregnation-calcination method, and then loads ZnIn2S4 nanosheets onto the CoO / ATP surface using a hydrothermal method to obtain a ZnIn2S4 / CoO / ATP ternary composite photocatalyst.
[0027] In a preferred embodiment of the present invention, ATP is uniformly dispersed in a 3 mol / L hydrochloric acid solution and reacted at a temperature of 70–90 °C. After the reaction, the mixture is centrifuged, washed until neutral, dried, and then ground for later use. To ensure uniform ATP acid treatment, the present invention involves stirring during the heating process at a rate of 300–1500 r / min for 9–11 h.
[0028] To anchor ultrafine CoO nanoparticles onto the surface of ATP nanorods, this invention first adds acid-modified ATP to a 0.032 mol / L cobalt nitrate solution, disperses it ultrasonically, and then stirs and mixes it. A 0.128 mol / L urea solution is then slowly added to form a mixture. The mixture is reacted at a temperature of 100–130 °C. The product is washed, dried, and calcined to obtain the CoO / ATP composite material. In a preferred embodiment of this invention, the calcination temperature is 350–450 °C, and the calcination time is 0.5–1.5 h.
[0029] In a preferred embodiment of the present invention, to load ZnIn2S4 nanosheets onto the synthesized CoO / ATP base, CoO / ATP powder was dispersed in a solvent of deionized water and ethylene glycol in a volume ratio of 5:1, and stirred to form a dispersion. Zinc chloride and indium trichloride tetrahydrate were added to the above solution and stirred until homogeneous. Finally, thioacetamide was added and thoroughly mixed, wherein the molar ratio of zinc source, indium source, and sulfur source was 1:2:4. The mixture was transferred to an autoclave and subjected to hydrothermal reaction at a temperature of 100-140 °C. After the reaction, the mixture was cooled, centrifuged, washed, and dried to obtain the ZnIn2S4 / CoO / ATP ternary composite photocatalyst.
[0030] In a preferred embodiment of the present invention, in order to ensure that the acidified ATP is thoroughly mixed, the present invention preferably employs mechanical grinding to grind the dried acidified ATP into a uniform powder.
[0031] Example 1 This embodiment provides a ZnIn2S4 / CoO / ATP ternary composite photocatalyst, and its preparation method is as follows: Step 1, Preparation of CoO / ATP complex A certain amount of 1 g of ATP was dispersed in 50 mL of HCl solution (3 M) by ultrasonic dispersion, stirred in a water bath at 80 °C for 10 h, centrifuged, and the precipitate was collected. The precipitate was washed several times with distilled water until the pH was neutral, and dried overnight at 60 °C to obtain acid-modified ATP. The ATP was then ground into a uniform powder. 0.097 g of the above ATP powder was uniformly dispersed in 20 mL of cobalt nitrate solution (0.032 mol / L), ultrasonically dispersed for 1 h, and stirred at room temperature at a stirring rate of 600 r / min for 20 min. Then, 20 mL of urea solution (0.128 mol / L) was slowly added, and the mixture was then heated in an oil bath at 115 °C for 1.5 h, washed 6 times with deionized water, and dried in a vacuum drying oven at 60 °C for 4 h. Finally, the mixture was calcined in a muffle furnace at 400 °C for 1 h at a rate of 3 °C / min.
[0032] Step 2, Preparation of ZnIn2S4 / CoO / ATP ternary composite photocatalyst: The 0.514 g CoO / ATP complex obtained in step 1 was ultrasonically dispersed in a beaker containing 25 mL deionized water and 5 mL ethylene glycol, and stirred vigorously at 600 r / min for 30 min at room temperature. 0.068 g ZnCl2 and 0.293 g InCl3·4H2O were added to the solution, and the mixture was stirred for 30 min. Then, 0.15 g thioacetamide was added, and the mixture was stirred for another 30 min. Finally, the solution was transferred to a 50 mL lined autoclave and dried in an oven at 120 °C for 12 h. After the reaction was complete and the mixture was allowed to cool naturally, it was centrifuged, washed twice alternately with ethanol and distilled water, and then vacuum dried at 60 °C for 4 h to obtain the ZnIn2S4 / CoO / ATP ternary composite photocatalyst of this embodiment.
[0033] Comparative Example 1 The only difference between this comparative example and Example 1 is that: In step 1 of this comparative example, no acidified ATP was added to obtain CoO powder. The specific preparation method is as follows: Step 1, Prepare CoO powder 20 mL of urea solution (0.128 mol / L) was slowly added to 20 mL of cobalt nitrate solution (0.032 mol / L), and ultrasonically dispersed for 1 h. After stirring at 600 r / min at room temperature for 20 min, the mixture was then heated in an oil bath at 115 ℃ for 1.5 h, washed 6 times with deionized water, and dried in a vacuum drying oven at 60 ℃ for 4 h. Finally, the mixture was calcined in a muffle furnace at 400 ℃ for 1 h at a rate of 3 ℃ / min.
[0034] Step 2, Preparation of ZnIn2S4 / CoO complex: The 0.257 g CoO powder obtained in step 1 was ultrasonically dispersed in a beaker containing 25 mL of deionized water and 5 mL of ethylene glycol, and stirred vigorously at 600 r / min for 30 min at room temperature. 0.068 g ZnCl2 and 0.293 g InCl3·4H2O were added to the solution, and the mixture was stirred for 30 min. Then, 0.15 g thioacetamide was added, and the mixture was stirred for another 30 min. Finally, the solution was transferred to a 50 mL lined autoclave and dried in an oven at 120 ℃ for 12 h. After the reaction was complete and the mixture was allowed to cool naturally, it was centrifuged, washed twice alternately with ethanol and distilled water, and then vacuum dried at 60 ℃ for 4 h to obtain the ZnIn2S4 / CoO composite material of this comparative example.
[0035] Comparative Example 2 The only difference between this comparative example and Comparative Example 1 is that: This comparative example omits step 2 and directly obtains CoO powder. The specific preparation method is as follows: 20 mL of urea solution (0.128 mol / L) was slowly added to 20 mL of cobalt nitrate solution (0.032 mol / L), and ultrasonically dispersed for 1 h. After stirring at 600 r / min at room temperature for 20 min, the mixture was then heated in an oil bath at 115 ℃ for 1.5 h, washed 6 times with deionized water, and dried in a vacuum drying oven at 60 ℃ for 4 h. Finally, the mixture was calcined in a muffle furnace at 400 ℃ for 1 h at a rate of 3 ℃ / min to obtain the CoO powder of this comparative example.
[0036] Comparative Example 3 The only difference between this comparative example and Example 1 is that: This comparative example only performs the first step of step 1. The specific preparation method is as follows: 1 g of ATP was dispersed in 50 mL of HCl solution (3 M) by ultrasonic dispersion and stirred in a water bath at 80 °C for 10 h. After the reaction, the precipitate was collected by centrifugation and washed several times with distilled water until the pH was neutral. After drying at 60 °C overnight, acid-modified ATP was obtained. The ATP was then ground into a uniform powder to obtain the acidified ATP material of this comparative example.
[0037] Comparative Example 4 The only difference between this comparative example and Comparative Example 1 is that: This comparative example does not perform step 1, and does not add CoO powder in step 2. The specific preparation method is as follows: ZnCl2, InCl3·4H2O, and thioacetamide were dissolved in 100 mL of ethylene glycol aqueous solution (ethylene glycol 1 / 6 vol%) at a molar ratio of 1:2:4 to obtain a mixture. The mixture was then transferred to an autoclave and hydrothermally reacted at 120 °C for 12 h. After the reaction, the mixture was cooled and filtered. The precipitate obtained by filtration was washed 6 times by centrifugation with ethanol and deionized water, and then vacuum dried at 60 °C for 4 h to obtain ZnIn2S4 powder sample.
[0038] Experimental Section (a) X-ray diffraction test X-ray diffraction tests were performed on ZnIn2S4 / CoO / ATP of Example 1, CoO of Comparative Example 2, ATP of Comparative Example 3, and ZnIn2S4 of Comparative Example 4. The results... Figure 1 As shown.
[0039] For acidified ATP, the diffraction peaks at 19.7 ° and 27.3 ° belong to the (040) and (400) crystal planes of ATP, respectively, and the diffraction peak at 26.6 ° belongs to the (101) crystal plane of the quartz impurity; for pure ZnIn2S4, all diffraction peaks can be attributed to the hexagonal ZnIn2S4 (JCPDS No. 65-2023); most of the characteristic diffraction peaks of CoO are consistent with the hexagonal CoO (JCPDS No. 42-1300), but the diffraction peak at approximately 57.3 ° is shifted to the right relative to the standard card, which is due to lattice distortion caused by the calcination process; in addition, the XRD pattern of the ZnIn2S4 / CoO / ATP composite material is similar to that of pure ZnIn2S4, and there are two diffraction peaks at 26.8 ° and 34.1 ° belonging to the (231) and (311) crystal planes of ATP, respectively.
[0040] (ii) Scanning electron microscopy test Scanning electron microscopy (SEM) analysis was performed on the ZnIn2S4 / CoO / ATP from Example 1, the CoO / ATP complex from the preparation process in Example 1, the ATP from Comparative Example 3, and the ZnIn2S4 from Comparative Example 4. The results... Figure 2 As shown.
[0041] in, Figure 2 a is a scanning electron microscope image of ZnIn2S4 in Comparative Example 4; Figure 2b is a scanning electron microscope image of acidified ATP in Comparative Example 3; Figure 2 c is a scanning electron microscope image of the CoO / ATP complex in the preparation process of Example 1; Figure 2 d is a scanning electron microscope image of ZnIn2S4 / CoO / ATP from Example 1.
[0042] And by Figure 2 It can be seen that the apparent morphology of ZnIn2S4 is a micron flower-like structure composed of nanosheets, and the acidified ATP is a one-dimensional rod-shaped crystal. Furthermore, the morphology of the CoO / ATP complex shows that the CoO nanoparticles are successfully anchored on the ATP surface. In ZnIn2S4 / CoO / ATP, ZnIn2S4 does not present as a flower-like microsphere but rather as dispersed nanosheets attached to CoO / ATP.
[0043] (III) Transmission electron microscopy test Transmission electron microscopy (TEM) analyses were performed on the ZnIn2S4 / CoO / ATP from Example 1, the CoO / ATP complex from the preparation process in Example 1, ATP from Comparative Example 3, and ZnIn2S4 from Comparative Example 4. The results are as follows: Figure 3 As shown.
[0044] in, Figure 3 a is a transmission electron microscope image of ZnIn2S4 in Comparative Example 4 at the 200 nm scale; Figure 3 b is a transmission electron microscope image of acidified ATP in Comparative Example 3 at a scale of 200 nm. Figure 3 c is a transmission electron microscope image of the CoO / ATP complex in the preparation process of Example 1 at a scale of 200 nm. Figure 3 d is a transmission electron microscope image of ZnIn2S4 / CoO / ATP in Example 1 at a scale of 200 nm.
[0045] Depend on Figure 3 It can be seen that the apparent morphology of ZnIn2S4 is a micron flower-like structure composed of nanosheets, and the acidified ATP is a one-dimensional rod-shaped crystal. Furthermore, the morphology of the CoO / ATP complex shows that the CoO nanoparticles are successfully anchored on the ATP surface. In ZnIn2S4 / CoO / ATP, ZnIn2S4 does not present as a flower-like microsphere but rather as dispersed nanosheets attached to CoO / ATP.
[0046] (iv) High-angle annular dark-field scanning transmission electron microscopy test The ZnIn2S4 / CoO / ATP from Example 1 was subjected to high-angle annular dark-field scanning transmission electron microscopy. Results Figure 4 As shown.
[0047] from Figure 4Three sets of lattice fringes with interplanar spacings of 0.26 nm, 0.20 nm and 0.32 nm can be seen, which correspond to the hexagonal CoO (111), hexagonal ZnIn2S4 (200) and (102) crystal planes, respectively.
[0048] (v) Ultraviolet-Visible Absorption Spectrum UV-Vis diffuse reflectance tests were performed on ZnIn2S4 / CoO / ATP from Example 1, CoO from Comparative Example 2, acidified ATP from Comparative Example 3, and ZnIn2S4 from Comparative Example 4. The results are as follows: Figure 5 As shown.
[0049] from Figure 5 It can be seen that the absorption band edge of pure ZnIn2S4 is around 524 nm, ATP is a wide-bandgap semiconductor with an absorption band edge below 400 nm, while CoO has two obvious absorption peaks at 385 and 647 nm. After loading ZnIn2S4 onto the CoO / ATP surface, the absorption in the ultraviolet region is weakened and the absorption band edge is slightly blue-shifted compared to pure ZnIn2S4. This may be due to the increased scattering of incident light caused by the porous structure or rough surface of CoO / ATP, and the significant enhancement of light absorption at 753 nm is attributed to local energy levels.
[0050] (vi) Photocatalytic hydrogen production performance test The materials prepared in Example 1 and Comparative Examples 1-4 were used as catalysts, and their photocatalytic hydrogen production performance was tested. The test methods are as follows: 10 mg of catalyst sample was dispersed in a quartz tube (50 mL volume) containing 15 mL of methanol-water solution (20 vol%). Argon gas was introduced for 15-20 min to purge the air. The quartz tube was then sealed with a rubber stopper and plastic sealing film and continuously stirred on a stirrer. A xenon lamp equipped with a 420 nm cutoff filter was used as a visible light source (λ>420 nm) to illuminate the quartz tube from the side. High-purity argon was used as the carrier gas, and the hydrogen production was monitored using gas chromatography to analyze the photocatalytic activity of the photocatalyst.
[0051] Figure 6 The curves show the hydrogen production over time when using the ZnIn2S4 / CoO / ATP photocatalyst of Example 1, the ZnIn2S4 / CoO of Comparative Example 1, the CoO of Comparative Example 2, the ATP of Comparative Example 3, and the ZnIn2S4 photocatalyst of Comparative Example 4.
[0052] from Figure 6 As can be seen, the ZnIn2S4 / CoO / ATP composite photocatalyst exhibits the best hydrogen production performance, and it is significantly improved compared to ZnIn2S4 / CoO.
[0053] (vii) Stability test of photocatalytic hydrogen production cycle Taking the ZnIn2S4 / CoO / ATP prepared in Example 1 as an example, the photocatalytic hydrogen production cycle stability when used as a catalyst was tested. The test method is as follows: 10 mg of the ZnIn2S4 / CoO / ATP prepared in Example 1 was dispersed into a quartz tube (50 mL volume) containing 15 mL of methanol-water solution (20 vol%). Argon gas was introduced for 15-20 min to purge the air. The quartz tube was then sealed with a rubber stopper and a plastic sealing film and continuously stirred on a stirrer. A xenon lamp equipped with a 420 nm cutoff filter was used as the visible light source (λ>420 nm) to illuminate the quartz tube from the side. The solution temperature was maintained at approximately 25 °C using a condensate circulation system. High-purity argon was used as the carrier gas, and the hydrogen production was monitored using a gas chromatograph to analyze the photocatalytic activity of the photocatalyst. Each hydrogen production test cycle was 2.5 h. Five consecutive cycles of hydrogen production tests were conducted under the same conditions to obtain the cyclic photocatalytic hydrogen production performance of the sample.
[0054] Figure 7 The graph shows the cycle stability test results of the ZnIn2S4 / CoO / ATP photocatalyst prepared in Example 1. Figure 7 As can be seen, after multiple cycles of hydrogen production tests, the sample still maintains good photocatalytic hydrogen production activity, indicating that the ZnIn2S4 / CoO / ATP ternary composite photocatalyst prepared in this invention has excellent photocatalytic stability.
[0055] Obviously, the above embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
Claims
1. A ZnIn2S4 / CoO / ATP ternary composite photocatalyst, characterized in that, The ZnIn2S4 / CoO / ATP ternary composite photocatalyst comprises a composite material consisting of a CoO / ATP composite material and ZnIn2S4 nanosheets grown on the surface of the CoO / ATP composite material, wherein the mass ratio of ZnIn2S4 to CoO / ATP is 3:
7.
2. A method for preparing a ZnIn2S4 / CoO / ATP ternary composite photocatalyst, characterized in that, Includes the following steps: Step 1: Disperse ATP in an acidic solution, stir the acidic solution containing ATP under heating conditions, centrifuge the reaction product after the reaction, wash until neutral, dry to obtain acid-modified ATP, and grind the acid-modified ATP into powder. Step 2: Add the acid-modified ATP powder obtained in Step 1 to the cobalt nitrate solution, disperse it by ultrasound and stir to mix. Slowly add urea solution to form a mixture. Stir the mixture under heating conditions to react. Wash, dry and calcine the reaction product to obtain the CoO / ATP composite material. Grind the CoO / ATP composite material into powder. Step 3: Disperse the CoO / ATP powder obtained in Step 2 in a solvent and stir to form a dispersion. Add zinc source, indium source and sulfur source to the dispersion in sequence and stir thoroughly. Transfer the stirred and mixed dispersion to a high-pressure reactor and carry out a hydrothermal reaction at a specific temperature. Cool the reaction dispersion, centrifuge, wash and dry to obtain the ZnIn2S4 / CoO / ATP ternary composite photocatalyst.
3. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, The heating temperature in step one is 70~90 ℃, the heating temperature in step two is 100~130 ℃, the calcination temperature in step two is 350~450 ℃, and the calcination time is 0.5~1.5 h. The hydrothermal reaction temperature in step three is 100~140 ℃, and the reaction time is 10~14 h. During the stirring process in steps one, two, and three, the stirring rate is 300~1500 r / min. The stirring time in step one is 9~11 h. The stirring time after ultrasonic dispersion in step two is 0.25~0.5 h, and the heating and stirring time is 1~2 h. The stirring time after each raw material is added in step three is 0.25~1 h.
4. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, The acid solution in step one is hydrochloric acid solution, the solvent in step three is a mixture of deionized water and ethylene glycol, the zinc source is zinc chloride, the indium source is indium trichloride tetrahydrate, and the sulfur source is thioacetamide.
5. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, The concentration of the hydrochloric acid solution is 3 mol / L, the concentration of the cobalt nitrate solution is 0.032 mol / L, the concentration of the urea solution is 0.128 mol / L, and the volume ratio of deionized water to ethylene glycol is 5:
1.
6. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, The molar ratio of the zinc source, indium source and sulfur source is 1:2:
4.
7. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, After centrifugation in steps one, two, and three, the product is washed several times with alternating ethanol and distilled water. The drying is performed under vacuum at a temperature of 50-70°C for 3-5 hours.
8. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, In step two, the calcination temperature is 350~450 ℃ and the calcination time is 0.5~1.5 h.
9. The preparation method of a ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2, characterized in that, The grinding in steps one and two is performed using mechanical grinding.
10. The application of the ZnIn2S4 / CoO / ATP ternary composite photocatalyst prepared by the method of preparing the ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 1 or the method of preparing the ZnIn2S4 / CoO / ATP ternary composite photocatalyst according to claim 2 in photocatalytic water splitting for hydrogen production.