Nickel-cobalt-selenium / methylamine-lead-iodine photocatalysts, their preparation and application, and photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added systems.

Abstract

This invention belongs to the field of energy catalysis technology, specifically relating to nickel-cobalt-selenium / methylamine-lead-iodine photocatalysts, their preparation and application, and a photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system. Methylamine-lead-iodine and nickel-cobalt-selenium nanosheets are added to a saturated solution of methylamine-lead-iodine, heated to react, cooled, and the precipitate is collected to obtain the nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst. Using nickel-cobalt-selenium as a co-catalyst can significantly improve the photocatalytic HI cracking hydrogen production performance of methylamine-lead-iodine, and a system utilizing I... ‑ / I3 ‑ The redox couple tandem photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system replaces the electrocatalytic oxygen evolution reaction with the photoelectrocatalytic biomass value-added reaction, further improving the efficiency of the reaction system.

Description

Technical Field

[0001] This invention belongs to the field of energy catalysis technology, specifically relating to nickel-cobalt-selenium / methylamine-lead-iodine photocatalysts and their preparation and application, and a photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Hydrogen energy possesses high energy density and is an ideal carbon-free energy carrier. Photocatalytic hydrogen evolution reaction (HER) using solar energy offers advantages such as low cost and zero pollution, and is considered a promising method for solving energy shortages and environmental pollution problems. The photocatalytic hydrogen production reaction is the cathode half-reaction of the photocatalytic water splitting reaction, and its potential is limited by the high reaction potential of the anodic oxygen evolution reaction. Compared to pure water splitting, the cracking of HI to produce H2 has significant thermodynamic advantages. Halide perovskites, represented by MAPbI3, can be stable in saturated HI solutions, achieving photocatalytic hydrogen production through HI cracking, marking a new breakthrough in photocatalytic hydrogen production systems based on perovskite photocatalysts. However, as the photocatalytic process proceeds, I2O inevitably occurs... - Oxidized to I3 - This process severely interferes with the light absorption of the catalyst. Existing technologies utilize tandem electrocatalysis to convert I3... - Restore to I - At the same time, it oxidizes water, while the reduced water is rich in I. - The solution continues the photocatalytic hydrogen production reaction; however, the introduced electrocatalytic oxygen evolution reaction requires a high overpotential, and the product O2 has low value, making it economically unattractive. Furthermore, the intrinsic catalytic activity of halide perovskites remains unsatisfactory, with hydrogen production rates far lower than those of traditional photocatalysts. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst, its preparation and application, and a photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system. Using nickel-cobalt-selenium as a co-catalyst can significantly improve the photocatalytic HI cracking performance of methylamine-lead-iodine for hydrogen production, and a system utilizing I... - / I3 - The redox couple tandem photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system replaces the electrocatalytic oxygen evolution reaction with the photoelectrocatalytic biomass value-added reaction, further improving the efficiency of the reaction system.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, a method for preparing a nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst includes the following steps:

[0007] S1. Nickel salt, cobalt salt and hexadecyltrimethylammonium bromide are dissolved in water and methanol and mixed and stirred to form solution one. Selenium powder is added to sodium borohydride aqueous solution and stirred to form solution two. Solution one and solution two are mixed and stirred and then subjected to hydrothermal reaction to obtain nickel cobalt selenium nanosheets.

[0008] S2. Mix methylamine solution and hydroiodic acid, stir and evaporate the solvent to obtain methylamine iodine; dissolve lead iodide in a mixed solution of hydroiodic acid and hypophosphorous acid, add excess methylamine iodine, heat and keep warm to crystallize until dynamic equilibrium is reached, cool to room temperature, and centrifuge to separate methylamine lead iodine and saturated methylamine lead iodine solution.

[0009] S3. Add methylamine lead iodine and nickel cobalt selenium nanosheets to a saturated solution of methylamine lead iodine, heat to react, cool, and collect the precipitate to obtain the nickel cobalt selenium / methylamine lead iodine photocatalyst.

[0010] Preferably, in step S1, the nickel salt includes nickel nitrate, the cobalt salt includes cobalt nitrate, and the molar ratio of nickel salt to cobalt salt is (1-0.8):(0-0.2), excluding 1:0; the ratio of the total number of moles of nickel salt and cobalt salt to the number of moles of selenium powder is 1:(2-2.2).

[0011] Preferably, in step S1, the hydrothermal reaction temperature is 170–190°C and the hydrothermal reaction time is 18–24 h.

[0012] Preferably, in step S2, the volume ratio of the methylamine solution and hydroiodic acid mixture is (1.9-2.1):1; the volume ratio of hydroiodic acid to hypophosphoric acid in the mixed solution of hydroiodic acid and hypophosphoric acid is (3.9-4.1):1; and the molar ratio of lead iodide to methylamine iodine is (0.95-1.05):1.

[0013] Preferably, in step S2, the temperature is raised to 94–96°C and held for 0.9–1.1 hours.

[0014] Preferably, in step S3, the mass ratio of methylamine lead iodine and nickel cobalt selenium nanosheets is 100:(1-5).

[0015] Preferably, in step S3, the mixture is heated to 95–105°C and reacted for 0.5–1.5 h.

[0016] In a second aspect, a nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst is obtained by the preparation method described in the first aspect.

[0017] Thirdly, as described in the second aspect, the application of the nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst in photocatalytic hydrogen production.

[0018] Fourthly, a photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system comprises a photocatalytic reaction system and a photoelectrocatalytic biomass value-added system; in the photocatalytic reaction system, the photocatalyst is the nickel cobalt selenide / methylamine lead iodine photocatalyst as described in the second aspect, and the reaction solution is a saturated solution of the nickel cobalt selenide / methylamine lead iodine photocatalyst as described in the second aspect; the anolyte of the photoelectrocatalytic biomass value-added system is a potassium borate buffer solution containing 5-hydroxymethylfurfural, and the cathode reaction chamber and the photocatalytic system circulate the reaction solution.

[0019] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0020] Nickel cobalt selenide / methylamine lead iodine photocatalyst has high carrier transport and separation efficiency. By optimizing the nickel-cobalt ratio in nickel cobalt selenide, the photocatalytic cracking performance of HI production by nickel cobalt selenide / methylamine lead iodine photocatalyst can be improved by a thousand times compared with that of uncomposite methylamine lead iodine.

[0021] Using I - / I3 - The photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system, which uses a redox couple in series, lowers the reaction barrier between the two reactions and replaces low-value OER with biomass oxidation, thus showing economic potential.

[0022] The photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system using nickel cobalt selenium / methylamine lead iodine photocatalyst can obtain the theoretical ratio of hydrogen and FDCA, while maintaining a solar energy conversion efficiency of 2.3% for a long time. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 Ni in Example 1 0.9 Co 0.1 (a) SEM image and (b) TEM image of Se2;

[0025] Figure 2 The images shown are (a) SEM images and (b) TEM images of MAPbI3 in Example 1.

[0026] Figure 3 Ni in Example 1 0.9 Co 0.1 (a) SEM image and (b) TEM image of Se2 / MAPbI3;

[0027] Figure 4 MAPbI3 and Ni in Example 1 0.9 Co0.1 XRD pattern of Se2 / MAPbI3;

[0028] Figure 5 For MAPbI3, NiSe2 / MAPbI3, Ni 0.95 Co 0.05 Se2 / MAPbI3, Ni 0.9 Co 0.1 Se2 / MAPbI3, Ni 0.85 Co 0.15 Se2 / MAPbI3 and Ni 0.8 Co 0.2 The photocatalytic activity of Se2 / MAPbI3 in HI cracking for hydrogen production;

[0029] Figure 6 This is a schematic diagram of the photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system in Example 6;

[0030] Figure 7 This is a reaction activity diagram of the photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system in Example 6. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0032] Example 1

[0033] 0.315 mmol Ni(NO3)2·6H2O, 0.035 mmol Co(NO3)2·6H2O, and 100 mg CTAB were dissolved in a mixture of 15 mL water and 15 mL methanol and stirred to form a clear solution (Solution 1). 60 mg Se powder was added to deionized water containing 60 mg NaBH4, and after gentle stirring for 30 minutes, a clear NaHSe solution was obtained (Solution 2). Solutions 1 and 2 were rapidly mixed and vigorously stirred for 30 minutes. The resulting solution was then placed in a high-temperature reactor and heated at 180 °C for 20 hours. After naturally cooling to room temperature, the solution was washed several times with deionized water and ethanol, and then dried in a vacuum oven at 60 °C. The resulting nickel-cobalt-selenium nanosheets were denoted as Ni. 0.9 Co 0.1 Se2.

[0034] like Figure 1 As shown, Ni 0.9 Co 0.1 Se2 has an ultrathin nanosheet structure with a size of approximately 100-200 nm.

[0035] 45 mL of methylamine solution (MA, 30-33% methanol solution) and 20 mL of HI (55-58% aqueous solution) were mixed in an ice-water bath and stirred for 2 h. The solvent was removed by rotary evaporation at 50 °C. The crude product was washed three times with diethyl ether and finally dried in a vacuum oven at 65 °C for 20 h to obtain methylamine iodine (MAI). 13.97 g of PbI2 was dissolved in a mixed solution of 40 mL of HI and 10 mL of H3PO2, and then 4.80 g of MAI was slowly added at 60 °C with vigorous stirring. The solution containing excess methylamine lead iodine was heated to 95 °C and kept at this temperature for 1 h to crystallize to dynamic equilibrium. After cooling to room temperature, a saturated solution containing black methylamine lead iodine (MAPbI3) precipitate was obtained at the bottom of the beaker. The MAPbI3 precipitate was separated from the saturated solution by centrifugation. The obtained MAPbI3 saturated solution was stored for subsequent operations and measurements, while the precipitate was dried in a vacuum oven at 80 °C to obtain MAPbI3 powder.

[0036] like Figure 2 As shown, MAPbI3 has a smooth surface, is dodecahedral in shape, and has a particle size of 50 μm. The lattice spacing observed in the TEM image is 0.31 nm, corresponding to the (220) plane of MAPbI3.

[0037] 100 mg of synthesized MAPbI3 powder and 3 mg of Ni 0.9 Co 0.1 Se2 was added to 10 mL of saturated MAPbI3 solution as the reaction system. The reaction system was then heated to 100 °C and held for 1 h, followed by cooling to room temperature. The resulting black nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst precipitate was denoted as Ni. 0.9 Co 0.1 Se2 / MAPbI3.

[0038] Example 2

[0039] Unlike Example 1, the amounts of Ni(NO3)2·6H2O and Co(NO3)2·6H2O were replaced with 0.3325 mmol and 0.0175 mmol, respectively, and the resulting nickel-cobalt-selenium nanosheets were denoted as Ni. 0.95 Co 0.05 Se2. The final black nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst precipitate is denoted as Ni. 0.95 Co 0.05 Se2 / MAPbI3.

[0040] Example 3

[0041] Unlike Example 1, the amounts of Ni(NO3)2·6H2O and Co(NO3)2·6H2O were replaced with 0.2975 mmol and 0.0525 mmol, respectively, and the resulting nickel-cobalt-selenium nanosheets were denoted as Ni.0.85 Co 0.15 Se2. The final black nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst precipitate is denoted as Ni. 0.85 Co 0.15 Se2 / MAPbI3.

[0042] Example 4

[0043] Unlike Example 1, the amounts of Ni(NO3)2·6H2O and Co(NO3)2·6H2O were replaced with 0.28 mmol and 0.07 mmol, respectively, and the resulting nickel-cobalt-selenium nanosheets were denoted as Ni. 0.8 Co 0.2 Se2. The final black nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst precipitate is denoted as Ni. 0.8 Co 0.2 Se2 / MAPbI3.

[0044] Comparative Example 1

[0045] Unlike Example 1, Co(NO3)2·6H2O was not added, and the amount of Ni(NO3)2·6H2O was 0.35 mmol, resulting in nickel selenium nanosheets denoted as NiSe2. NiSe2 was used instead of Ni. 0.9 Co 0.1 Se2 was used to obtain the nickel selenium / methylamine lead iodine photocatalyst, denoted as NiSe2 / MAPbI3.

[0046] Example 5

[0047] The photocatalytic reaction was carried out in a Pyrex reactor connected to a closed gas circulation and vacuum system. 100 mg of the photocatalyst (MAPbI3, NiSe2 / MAPbI3, Ni...) was scraped off. 0.95 Co 0.05 Se2 / MAPbI3, Ni 0.9 Co 0.1 Se2 / MAPbI3, Ni 0.85 Co 0.15 Se2 / MAPbI3 and Ni 0.8 Co 0.2 The reaction mixture (one of Se2 / MAPbI3) was immersed in 50 mL of saturated solution. The system was evacuated for 30 minutes to ensure complete removal of air, and then irradiated from the top with a 300W xenon lamp (PLS-SXE300D, Beijing Perfect Light Technology Co., Ltd.) equipped with an AM1.5G filter. The reaction suspension was maintained at 298 K using a cooling water stream. The separated gases were analyzed by gas chromatography (GC-7290, TCD, with Ar as the carrier gas).

[0048] like Figure 5As shown, the hydrogen production rate of MAPbI3 is only 2.14 μmol / h. -1 The activity was significantly improved after loading with nickel-cobalt-selenium (NiCo). When the Ni:Co ratio was optimized to 0.9:0.1, the activity of NiCo was significantly improved. 0.9 Co 0.1 The Se2 / MAPbI3 ratio achieved the optimal hydrogen production activity of 2592.36 μmol / h. -1 It is more than a thousand times better than MAPbI3 and ranks among the top in reported photocatalytic decomposition of HI systems.

[0049] Example 6

[0050] First, a WO3 film was grown on an FTO glass slide by adding 5 mL of 0.1 M Na2WO4·2H2O (99.5%) dropwise to 10 mL of 0.1 M H2C2O4 (99%). Then, 10 mL of 1 M HCl was added to the mixture, and the mixture was sonicated for 15 minutes. The solution was then transferred to a high-temperature reactor, and the FTO was placed vertically. The reactor was heated at 180 °C for 6 hours, then cooled to room temperature, and the FTO glass was washed with deionized water. Subsequently, 0.1 mmol FeCl3·6H2O (99%) and 0.2 mmol urea (99.999%) were added to 30 mL of water, and the WO3-grown FTO was placed in this solution for 12 hours. The FTO surface was then rinsed with water and ethanol and dried in an oven. Finally, the FTO was annealed in air at 320 °C for two hours to obtain an α-Fe2O3 / WO3 photoanode.

[0051] Ni 0.9 Co 0.1 Se2 / MAPbI3 undergoes photocatalytic cracking of HI to produce hydrogen in its saturated solution while simultaneously oxidizing I. - For I3 - The solution in the photocatalytic reaction cell is transferred to the cathode cell of the photoelectrophotocatalytic reaction cell via a peristaltic pump. The cathode of the photoelectrophotocatalytic reaction cell is connected to carbon cloth, and the anode is connected to an α-Fe₂O₃ / WO₃ photoanode. The solution in the anode chamber is a potassium borate buffer solution containing HMF. A proton exchange membrane is sandwiched between the anode and cathode chambers for conducting H₂. + and OH - OER is performed in the anode chamber of the photoelectrochemical reactor, while I3 is performed in the cathode chamber. - The reduction process involves circulating the acid solution in the cathode chamber and the acid solution in the photocatalytic reaction tank using a peristaltic pump, to construct a system as follows: Figure 6 The system shown is a photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system.

[0052] like Figure 7As shown, the molar amounts of redox products in the photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system are basically consistent. The oxidation products include 2,5-furandicarboxylic acid (FDCA), 5-formyl-2-furancarboxylic acid (FFCA), and 2,5-diformylfuran (DFF), and the solar energy to hydrogen energy conversion efficiency (STH) can be kept stable at 2.3% for a long time.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst, characterized in that, Includes the following steps: S1. Nickel salt, cobalt salt and hexadecyltrimethylammonium bromide are dissolved in water and methanol and mixed and stirred to form solution one. Selenium powder is added to sodium borohydride aqueous solution and stirred to form solution two. Solution one and solution two are mixed and stirred and then subjected to hydrothermal reaction to obtain nickel cobalt selenium nanosheets. S2. Mix methylamine solution and hydroiodic acid, stir and evaporate the solvent to obtain methylamine iodine; dissolve lead iodide in a mixed solution of hydroiodic acid and hypophosphorous acid, add excess methylamine iodine, heat and keep warm to crystallize until dynamic equilibrium is reached, cool to room temperature, and centrifuge to separate methylamine lead iodine and saturated methylamine lead iodine solution. S3. Add methylamine lead iodine and nickel cobalt selenium nanosheets to a saturated solution of methylamine lead iodine, heat to react, cool, and collect the precipitate to obtain the nickel cobalt selenium / methylamine lead iodine photocatalyst.

2. The preparation method according to claim 1, characterized in that, In step S1, the nickel salt includes nickel nitrate, the cobalt salt includes cobalt nitrate, and the molar ratio of nickel salt to cobalt salt is (1~0.8):(0~0.2), excluding 1:0; the ratio of the total number of moles of nickel salt and cobalt salt to the number of moles of selenium powder is 1:(2~2.2).

3. The preparation method according to claim 1, characterized in that, In step S1, the hydrothermal reaction temperature is 170~190 ℃ and the hydrothermal reaction time is 18~24 h.

4. The preparation method according to claim 1, characterized in that, In step S2, the volume ratio of methylamine solution to hydroiodic acid is (1.9~2.1):1; the volume ratio of hydroiodic acid to hypophosphoric acid in the mixed solution of hydroiodic acid and hypophosphoric acid is (3.9~4.1):1; and the molar ratio of lead iodide to methylamine iodine is (0.95~1.05):

1.

5. The preparation method according to claim 1, characterized in that, In step S2, heat to 94~96 ℃ and hold for 0.9~1.1 h.

6. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of methylamine lead iodine and nickel cobalt selenium nanosheets is 100:(1~5).

7. The preparation method according to claim 1, characterized in that, In step S3, the mixture is heated to 95~105 °C and reacted for 0.5~1.5 h.

8. A nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst, characterized in that, Obtained by the preparation method described in any one of claims 1 to 7.

9. The application of the nickel-cobalt-selenium / methylamine-lead-iodine photocatalyst as described in claim 8 in photocatalytic hydrogen production.

10. A photocatalytic hydrogen production coupled with photoelectrocatalytic biomass value-added system, characterized in that, It consists of a photocatalytic reaction system and a photoelectrocatalytic biomass value-added system; the photocatalyst in the photocatalytic reaction system is the nickel cobalt selenium / methylamine lead iodine photocatalyst as described in claim 8, and the reaction solution is a saturated solution of the nickel cobalt selenium / methylamine lead iodine photocatalyst as described in claim 8; the anolyte of the photoelectrocatalytic biomass value-added system is a potassium borate buffer solution containing 5-hydroxymethylfurfural, and the cathode reaction chamber and the photocatalytic system circulate the reaction solution.

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