A-site cation regulated halide perovskite as well as preparation method and application thereof

Abstract

The preparation method specifically comprises the following steps: mixing organic amine with a solvent, dropwise adding acid in an ice-water bath, stirring the obtained reaction mixture, removing the solvent, rinsing the formed solid with dry ether, and carrying out vacuum drying to obtain A-site cations; a-site cations and bismuth salt are dissolved in a solvent, heating and stirring are performed to form a uniform precursor solution, the solvent is removed, vacuum drying and grinding are performed, and halide perovskite with different A-site cations is obtained. The invention also discloses an application of the A-site cation regulated halide perovskite in photocatalytic carbon dioxide conversion. The preparation method comprises the following steps: dissolving raw materials by adopting a volatile alcohol solvent to obtain a uniform reaction precursor, then removing the solvent, and grinding to prepare the A-site cation regulated halide perovskite. The method is simple, safe, easy to operate and easy for large-dose production, and the novel simple and convenient synthetic route can be widely applied to preparation of such materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite material preparation, and in particular relates to a halide perovskite regulated by A-site cations, and also relates to a preparation method and application of the halide perovskite regulated by A-site cations. Background Art

[0002] Metal halide perovskites with the chemical structure of ABX (A: usually a monovalent organic cation, B: a divalent or trivalent cation, X: a halide anion) are a class of semiconductor materials with broad prospects for optoelectronic applications. Due to their low synthesis cost, adjustable band gap, wide visible light response range, long carrier lifetime, large absorption coefficient and good charge mobility, they have successfully inspired the application research of halide perovskites in the field of photocatalysis. As a class of photocatalysts with excellent optoelectronic properties, the band structure and optoelectronic properties of halide perovskites are mainly related to the MX6 octahedral unit configuration contributed by the band edge electronic structure. However, the direct contribution of the A-position cation to the electronic structure band edge state and the mechanism of photocatalytic activity are currently vacant. Therefore, it is crucial to study the direct contribution of the A cation connected to the ammonium group tail chain to the electronic structure band edge state and further understand its mechanism of action with photocatalytic activity.

[0003] Most of the synthesis methods of halide perovskites are prepared by dissolving and reprecipitating in a saturated aqueous solution of hydrobromic acid or hydroiodic acid. However, the preparation process and post-treatment process are relatively cumbersome, the operation is relatively complicated, and there are problems such as large input of raw materials and low system safety. Therefore, it is of great significance to develop a simple, safe and easy-to-operate synthesis method. Summary of the invention

[0004] The first objective of the present invention is to provide a method for preparing halide perovskite regulated by A-site cations, which solves the problem of complex preparation process and low catalytic activity of existing halide perovskites.

[0005] The second object of the present invention is to provide halide perovskites regulated by A-site cations.

[0006] The third object of the present invention is to provide the application of halide perovskite regulated by A-site cations in photocatalytic carbon dioxide conversion.

[0007] The technical solution adopted by the present invention is a method for preparing a halide perovskite regulated by cations at the A position, which is characterized by being implemented specifically according to the following steps:

[0008] Step 1, mixing an organic amine with a solvent, adding an acid dropwise in an ice-water bath, stirring the obtained reaction mixture, and then removing the solvent with a rotary evaporator, rinsing the formed solid with dry ether, and vacuum drying to obtain the A-site cation;

[0009] Step 2: dissolving the A-site cation and bismuth salt in a solvent, heating and stirring to form a uniform precursor solution, then removing the solvent with a rotary evaporator, vacuum drying, and grinding to obtain halide perovskites with different A-site cations.

[0010] The present invention is also characterized in that:

[0011] In step 1, the organic amine is specifically 4,5-dihydrothiazol-2-amine, 2-aminothiazole, 2-aminobenzothiazole, 2-aminobenzoxazole, 2-aminobenzoselenazole, benzylamine, 1-naphthylmethylamine, 2-(aminomethyl)naphthalene, 4-fluorobenzylamine, 4-chlorobenzylamine, 4-bromobenzylamine, 4-nitrobenzylamine, 4-(trifluoromethyl)benzylamine, 4-methylbenzylamine, 4-methoxybenzylamine, 3-fluorobenzylamine, 3-chlorobenzylamine, 3-bromobenzylamine, 3-nitrobenzylamine, 3-(trifluoromethyl)benzylamine, 3-methylbenzylamine, 3-methoxybenzylamine, 2-fluorobenzylamine, 2-chlorobenzylamine, 2-bromobenzylamine, 2-nitrobenzylamine, 2-(trifluoromethyl)benzylamine, 2-methylbenzylamine, and any one of 2-methoxybenzylamine.

[0012] In step 1, the solvent is anhydrous ethanol or anhydrous methanol; the acid is hydrobromic acid, and the molar ratio of the organic amine, the acid and the solvent is 1:1-1.2:10-20. The stirring time is 6-12 hours; the temperature when removing the solvent is 35-50°C, the time is 0.5-1 hour; the vacuum drying temperature is 40-60°C, and the drying time is 8-12 hours.

[0013] In step 2, the A-site cation is 4,5-dihydrothiazol-2-amine hydrobromide, 2-aminothiazole hydrobromide, 2-aminobenzothiazole hydrobromide, 2-aminobenzoxazole hydrobromide, 2-aminobenzoselenazole hydrobromide, benzylamine hydrobromide, 1-naphthylmethylamine hydrobromide, 2-(aminomethyl)naphthalene hydrobromide, 4-fluorobenzylamine hydrobromide, 4-chlorobenzylamine hydrobromide, 4-bromobenzylamine hydrobromide, 4-nitrobenzylamine hydrobromide, 4-(trifluoromethyl)benzylamine hydrobromide, 4-methylbenzylamine hydrobromide, 4-methoxybenzylamine hydrobromide, 3-fluorobenzylamine hydrobromide, 3-chlorobenzylamine hydrobromide, 3-bromobenzylamine hydrobromide, 3-nitrobenzylamine hydrobromide, 3-(trifluoromethyl)benzylamine hydrobromide, 3-methylbenzylamine hydrobromide, 3-methoxybenzylamine hydrobromide, 2-fluorobenzylamine hydrobromide, 2-chlorobenzylamine hydrobromide, 2-bromobenzylamine hydrobromide, 2-nitrobenzylamine hydrobromide, 2-(trifluoromethyl)benzylamine hydrobromide, 2-methylbenzylamine hydrobromide, 2-methoxybenzylamine hydrobromide.

[0014] In step 2, the bismuth salt is BiBr3; the solvent is anhydrous ethanol or anhydrous methanol; and the molar ratio of the A-site cation, the bismuth salt and the solvent is 1-2:1:5-10.

[0015] The heating temperature is 40-60°C; the stirring time is 0.5-1h; the vacuum drying temperature is 40-60°C, and the vacuum drying time is 5-12h.

[0016] The second technical solution adopted by the present invention is the halide perovskite prepared by the preparation method of the halide perovskite regulated by the A-site cation.

[0017] The third technical solution adopted by the present invention is that the halide perovskite regulated by the A-site cation has the ability to photocatalyze CO2 reduction, and the reduction products are CO and CH4, among which CO is the main product, accompanied by a small amount of CH4 product.

[0018] The beneficial effect of the present invention is that the present invention uses a volatile alcohol solvent to dissolve the raw material to obtain a uniform reaction precursor, then removes the solvent, and grinds to prepare an A-site cation-regulated halide perovskite. The method is not only simple, safe, easy to operate, and easy to produce in large doses, but this new and simple synthetic route can be widely used in the preparation of such materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a unit cell diagram of the halide perovskite DTABiBr4 crystal regulated by the A-site cation of the present invention;

[0020] Figure 2 It is the XRD spectrum of the halide perovskite DTABiBr4 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0021] Figure 3 This is a unit cell diagram of the halide perovskite TABiBr4 crystal regulated by the A-site cation of the present invention;

[0022] Figure 4 It is the XRD spectrum of the halide perovskite TABiBr4 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0023] Figure 5 This is a unit cell diagram of the halide perovskite BTABiBr4 crystal regulated by the A-site cation of the present invention;

[0024] Figure 6 It is the XRD spectrum of the halide perovskite BTABiBr4 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0025] Figure 7 This is a unit cell diagram of the halide perovskite BOABiBr4 crystal regulated by the A-site cation of the present invention;

[0026] Figure 8 It is the XRD spectrum of the halide perovskite BOABiBr4 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0027] Fig. 9 This is a unit cell diagram of the halide perovskite BSABiBr4 crystal regulated by the A-site cation of the present invention;

[0028] Fig.10 It is the XRD spectrum of the halide perovskite BSABiBr4 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0029] Fig.11 This is a unit cell diagram of the halide perovskite PMA2BiBr5 crystal regulated by the A-site cation of the present invention;

[0030] Fig.12 It is the XRD spectrum of the halide perovskite PMA2BiBr5 material regulated by the A-site cation of the present invention and its simulated crystal XRD spectrum;

[0031] Fig.13 It is the halide perovskite regulated by the A-position cation of the present invention. 1 Unit cell diagram of NMA2BiBr5 crystal;

[0032] Fig.14 It is the halide perovskite regulated by the A-position cation of the present invention. 1 XRD spectra of NMA2BiBr5 material and its simulated crystal XRD spectra;

[0033] Fig.15 It is the halide perovskite regulated by the A-position cation of the present invention. 2 Unit cell diagram of NMA2BiBr5 crystal;

[0034] Fig.16 It is the halide perovskite regulated by the A-position cation of the present invention. 2 XRD spectra of NMA2BiBr5 material and its simulated crystal XRD spectra;

[0035] Fig.17 This is a graph of the photocatalytic CO2 conversion rate of the halide perovskite ABiBr4 regulated by the A-site cation of the present invention;

[0036] Fig.18 This is a diagram of the photocatalytic CO2 conversion rate of the halide perovskite A2BiBr5 regulated by the A-site cation of the present invention. DETAILED DESCRIPTION

[0037] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] The preparation method of the halide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0039] Step 1, preparing the A-position cations of different organic amine hydrobromates; specifically:

[0040] The organic amine is mixed with a solvent, and an acid is added dropwise in an ice-water bath at 0°C. The resulting reaction mixture is stirred, and then the solvent is removed by a rotary evaporator. The resulting solid is rinsed with dry ether and dried in vacuo to obtain the A-site cation;

[0041] The organic amine is specifically any one of 4,5-dihydrothiazol-2-amine, 2-aminothiazole, 2-aminobenzothiazole, 2-aminobenzoxazole, 2-aminobenzoselenazole, benzylamine, 1-naphthylmethylamine, 2-(aminomethyl)naphthalene, 4-fluorobenzylamine, 4-chlorobenzylamine, 4-bromobenzylamine, 4-nitrobenzylamine, 4-(trifluoromethyl)benzylamine, 4-methylbenzylamine, 4-methoxybenzylamine, 3-fluorobenzylamine, 3-chlorobenzylamine, 3-bromobenzylamine, 3-nitrobenzylamine, 3-(trifluoromethyl)benzylamine, 3-methylbenzylamine, 3-methoxybenzylamine, 2-fluorobenzylamine, 2-chlorobenzylamine, 2-bromobenzylamine, 2-nitrobenzylamine, 2-(trifluoromethyl)benzylamine, 2-methylbenzylamine, and 2-methoxybenzylamine;

[0042] The solvent is anhydrous ethanol or anhydrous methanol;

[0043] The acid is hydrobromic acid, and the mass fraction of hydrobromic acid is 48%;

[0044] The molar ratio of organic amine, acid and solvent is 1:1-1.2:10-20;

[0045] The stirring time is 6-12h; the temperature when removing the solvent is 35-50°C and the time is 0.5-1h;

[0046] The vacuum drying temperature is 40-60°C and the drying time is 8-12h.

[0047] Step 2: dissolving the A-site cation and bismuth salt in a solvent, heating and stirring to form a uniform precursor solution, then removing the solvent with a rotary evaporator, vacuum drying, and grinding with an agate mortar to obtain halide perovskites with different A-site cations.

[0048] The A-site cation is 4,5-dihydrothiazol-2-amine hydrobromide, 2-aminothiazole hydrobromide, 2-aminobenzothiazole hydrobromide, 2-aminobenzoxazole hydrobromide, 2-aminobenzoselenazole hydrobromide, benzylamine hydrobromide, 1-naphthylmethylamine hydrobromide, 2-(aminomethyl)naphthalene hydrobromide, 4-fluorobenzylamine hydrobromide, 4-chlorobenzylamine hydrobromide, 4-bromobenzylamine hydrobromide, 4-nitrobenzylamine hydrobromide, 4-(trifluoromethyl)benzylamine hydrobromide, 4-methylbenzylamine hydrobromide, 4- Any one of methoxybenzylamine hydrobromide, 3-fluorobenzylamine hydrobromide, 3-chlorobenzylamine hydrobromide, 3-bromobenzylamine hydrobromide, 3-nitrobenzylamine hydrobromide, 3-(trifluoromethyl)benzylamine hydrobromide, 3-methylbenzylamine hydrobromide, 3-methoxybenzylamine hydrobromide, 2-fluorobenzylamine hydrobromide, 2-chlorobenzylamine hydrobromide, 2-bromobenzylamine hydrobromide, 2-nitrobenzylamine hydrobromide, 2-(trifluoromethyl)benzylamine hydrobromide, 2-methylbenzylamine hydrobromide and 2-methoxybenzylamine hydrobromide;

[0049] The bismuth salt is BiBr3; the solvent is anhydrous ethanol or anhydrous methanol;

[0050] The molar ratio of the A-site cation, the bismuth salt and the solvent is 1-2:1:5-10;

[0051] The heating temperature is 40-60°C; the stirring time is 0.5-1h; the vacuum drying temperature is 40-60°C, and the vacuum drying time is 5-12h.

[0052] The present invention utilizes an extremely simple solvent removal method to prepare bismuth-based bromide halide perovskites with different A-site cations, and exerts the direct influence of the A-site cations on the band edge states, thereby studying their influence on the photocatalytic performance.

[0053] The different A-site cation bismuth-based halide perovskite powders prepared by the method of the present invention are used for photocatalytic carbon dioxide conversion, specifically:

[0054] The photocatalytic CO2 reduction performance was evaluated in a system consisting of a fully enclosed quartz reactor, a 300W xenon lamp, and a gas chromatograph (GC). To eliminate the thermal effect of irradiation, circulating water was passed through the reactor to maintain the reactor temperature at 20°C. 10 mg of bismuth-based bromide perovskite powder materials regulated by different A-site cations were ultrasonically dispersed in 1.0 mL of ethyl acetate, and then the mixed solution was spread on a glass fiber membrane and vacuum dried to remove excess ethyl acetate. CO2 gas (99.99%) was bubbled in water (298K) to form a mixture of CO2 gas and water vapor. Before irradiation, the atmosphere of the reactor was replaced by a mixed vapor of CO2 and H2O for 1 h to remove O2 and other foreign gases. The reactor was then sealed and finally filled with 101 kPa of CO2 and H2O vapor. During the reaction, the gas products collected were analyzed every hour using a gas chromatograph equipped with a flame ionization detector (FID) and a thermal conductivity detector (TCD).

[0055] Example 1

[0056] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0057] Step 1, weigh 4,5-dihydrothiazol-2-amine (102 mg, 1.00 mmol) in a 50 mL round-bottom flask, add 7 mL of anhydrous ethanol solution, and add 0.2 mL of hydrobromic acid (48 wt.%) dropwise in an ice-water bath at 0°C. Stir the reaction mixture for 6 hours, then remove the solvent using a rotary evaporator, rinse the formed solid with dry ether, and dry the product in vacuum at 50°C for 12 hours to obtain the target product 4,5-dihydrothiazol-2-amine hydrobromide (DTABr) as a white solid.

[0058] Step 2, DTABr (109.8 mg) and BiBr3 (269.0 mg) (molar ratio of 1:1) were dissolved in anhydrous methanol (10 mL) to form a uniform DTABiBr4 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow DTABiBr4 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0059] DTABr (11.0 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, the solution was placed in a sealed container with a small pore membrane to slowly evaporate the saturated solution solvent to obtain the grown DTABiBr4 single crystal. The single crystal crystal structure of a bismuth-based bromide perovskite grown by A-site cation regulation was tested by single crystal X-ray diffractometer. Figure 1The crystal structure of DTABiBr4 single crystal is shown. It can be seen from the figure that DTABiBr4 is composed of octahedral BiBr4 - and DTA + The cations are combined through strong interactions.

[0060] The structure of the prepared A-site cation-regulated bismuth-based bromide perovskite material was tested by powder X-ray diffractometer (XRD). Figure 2 The prepared DTABiBr4 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0061] Example 2

[0062] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0063] Step 1, 2-aminothiazole (100 mg, 1.00 mmol) was placed in a 50 mL round-bottom flask, 7 mL of anhydrous ethanol solution was added, and 0.2 mL of hydrobromic acid (48 wt.%) was added dropwise in an ice-water bath at 0°C. The reaction mixture was stirred for 6 h, and then the solvent was removed by a rotary evaporator. The formed solid was rinsed with dry ether, and the product was vacuum dried at 50°C for 12 h to obtain the target product 2-aminothiazole hydrobromide (TABr) as a white solid.

[0064] Step 2, TABr (108.6 mg) and BiBr3 (269.0 mg) (molar ratio of 1:1) were dissolved in anhydrous methanol (10 mL) to form a uniform TABiBr4 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow TABiBr4 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0065] TABr (10.9 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, the solution was placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the grown TABiBr4 single crystal.

[0066] Figure 3 The crystal structure of TABiBr4 single crystal is shown. It can be seen from the figure that TABiBr4 is composed of octahedral BiBr4 - and TA + The cations are combined through strong interactions.

[0067] Figure 4The prepared TABiBr4 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0068] Example 3

[0069] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0070] Step 1, 2-aminobenzothiazole (150 mg, 1.00 mmol) was placed in a 50 mL round-bottom flask, 7 mL of anhydrous ethanol solution was added, and 0.2 mL of hydrobromic acid (48 wt.%) was added dropwise in an ice-water bath at 0°C. The reaction mixture was stirred for 6 h, and then the solvent was removed by a rotary evaporator. The formed solid was rinsed with dry ether, and the product was vacuum dried at 50°C for 12 h to obtain the target product 2-aminobenzothiazole hydrobromide (BTABr) as a white solid.

[0071] Step 2, BTABr (137.8 mg) and BiBr3 (269.0 mg) (molar ratio of 1:1) were dissolved in anhydrous methanol (10 mL) to form a uniform BTABiBr4 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow BTABiBr4 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0072] BTABr (13.9 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, the solution was placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly, thereby obtaining a grown BTABiBr4 single crystal. Figure 5 The crystal structure of BTABiBr4 single crystal is shown. It can be seen from the figure that BTABiBr4 is composed of octahedral BiBr4 - and BTA + The cations are combined through strong interactions.

[0073] Figure 6 The prepared BTABiBr4 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0074] Example 4

[0075] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0076] Step 1, weigh 2-aminobenzoxazole (134 mg, 1.00 mmol) in a 50 mL round-bottom flask, add 7 mL of anhydrous ethanol solution, and add 0.2 mL of hydrobromic acid (48 wt.%) dropwise in an ice-water bath at 0°C. The reaction mixture is stirred for 6 h, and then the solvent is removed by a rotary evaporator. The formed solid is rinsed with dry ether, and the product is vacuum dried at 50°C for 12 h to obtain the target product 2-aminobenzoxazole hydrobromide (BOABr) as a white solid.

[0077] Step 2, BOABr (129.0 mg) and BiBr3 (269.0 mg) (molar ratio of 1:1) were dissolved in anhydrous methanol (10 mL) to form a uniform BOABiBr4 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow BOABiBr4 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0078] BOABr (12.9 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, the solution was placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the grown DTABiBr4 single crystal. Figure 7 The crystal structure of BOABiBr4 single crystal is shown. It can be seen from the figure that BOABiBr4 is composed of octahedral BiBr4 - and BOA + The cations are combined through strong interactions.

[0079] Figure 8 The prepared BOABiBr4 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0080] Example 5

[0081] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0082] Step 1, 2-aminobenzoselenazole (197 mg, 1.00 mmol) was placed in a 50 mL round-bottom flask, 7 mL of anhydrous ethanol solution was added, and 0.2 mL of hydrobromic acid (48 wt.%) was added dropwise in an ice-water bath at 0°C. The reaction mixture was stirred for 6 h, and then the solvent was removed by a rotary evaporator. The formed solid was rinsed with dry ether, and the product was vacuum dried at 50°C for 12 h. After drying, the target product 2-aminobenzoselenazole hydrobromide (BSABr) was obtained as a white solid.

[0083] Step 2, BSABr (166.8 mg) and BiBr3 (269.0 mg) (molar ratio of 1:1) were dissolved in anhydrous methanol (10 mL) to form a uniform BSABiBr4 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow BSABiBr4 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0084] BSABr (16.7 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, it was placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the grown BSABiBr4 single crystal. Fig. 9 The crystal structure of BSABiBr4 single crystal is shown. It can be seen from the figure that BSABiBr4 is composed of octahedral BiBr4 - and BSA + The cations are combined through strong interactions.

[0085] Fig.10 The prepared BSABiBr4 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0086] Example 6

[0087] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0088] Step 1, weigh benzylamine (107 mg, 1.00 mmol) in a 50 mL round-bottom flask, add 7 mL of anhydrous ethanol solution, and add about 0.2 mL of hydrobromic acid (48 wt.%) dropwise in an ice-water bath at 0°C. The reaction mixture is stirred for 6 h, and then the solvent is removed by a rotary evaporator. The formed solid is rinsed with dry ether, and the product is vacuum dried at 50°C for 12 h to obtain the target product benzylamine hydrobromide (PMABr) as a white solid.

[0089] Step 2, PMABr (225.7 mg) and BiBr3 (269.0 mg) (molar ratio of 2:1) were dissolved in anhydrous methanol (10 mL) to form a uniform PMA2BiBr5 precursor solution, which was stirred at 50°C for 1 h. The solvent was then removed by a rotary evaporator, and the yellow PMA2BiBr5 product was vacuum dried at 50°C for 12 h, and ground using an agate mortar to obtain the final solid powder product.

[0090] PMABr (22.6 mg) and BiBr3 (26.9 mg) (molar ratio of 2:1) were dissolved in 1.5 mL of anhydrous methanol. In order to control the growth rate of the crystal, the solution was placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the grown PMA2BiBr5 single crystal. Fig.11 The crystal structure of PMA2BiBr5 single crystal is shown. It can be seen from the figure that PMA2BiBr5 is composed of octahedral BiBr5 2- and PMA + The cations are combined through strong interactions.

[0091] Fig.12 The prepared PMA2BiBr5 material powder XRD and its corresponding crystal simulation XRD are shown. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0092] Example 7

[0093] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0094] Step 1, weigh 1-naphthylmethylamine (157 mg, 1.00 mmol) in a 50 mL round-bottom flask, add 7 mL of anhydrous ethanol solution, and add about 0.2 mL of hydrobromic acid (48 wt.%) dropwise in an ice-water bath at 0°C. The reaction mixture is stirred for 6 h, and then the solvent is removed by a rotary evaporator. The formed solid is rinsed with dry ether, and the product is vacuum dried at 50°C for 12 h. After drying, the target product 1-naphthylmethylamine hydrobromide ( 1 NMABr).

[0095] Step 2: 1 NMABr (285.8 mg) and BiBr3 (269.0 mg) (molar ratio 1:1) were dissolved in anhydrous methanol (10 mL) to form a homogeneous 1 The NMA2BiBr5 precursor solution was stirred at 50°C for 1 h. The solvent was then removed by rotary evaporation and the yellow 1The NMA2BiBr5 product was vacuum dried at 50 °C for 12 h and ground using an agate mortar to obtain the final solid powder product.

[0096] Will 1 NMABr (28.6 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in a mixed solution of 1.5 mL of anhydrous methanol and 0.5 mL of tetrahydrofuran. In order to control the growth rate of the crystals, they were placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the growing 1 NMA2BiBr5 single crystal. Fig.13 Shown 1 The crystal structure of NMA2BiBr5 single crystal is shown in the figure. 1 NMA2BiBr5 is composed of octahedral BiBr5 2- and 1 NMA + The cations are combined through strong interactions.

[0097] Fig.14 Shows the preparation 1 NMA2BiBr5 material powder XRD and its corresponding crystal simulation XRD. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0098] Example 8

[0099] The preparation method of the bismuth-based bromide perovskite regulated by the A-site cation of the present invention is specifically implemented according to the following steps:

[0100] Step 1, weigh 2-(aminomethyl)naphthalene (157 mg, 1.00 mmol) in a 50 mL round-bottom flask, add 7 mL of anhydrous ethanol solution, and add 0.2 mL of hydrobromic acid (48 wt.%) dropwise in an ice-water bath at 0°C. The reaction mixture was stirred for 6 h, and then the solvent was removed by a rotary evaporator. The formed solid was rinsed with dry ether, and the product was vacuum dried at 50°C for 12 h. After drying, a white solid target product 2-(aminomethyl)naphthalene hydrobromide ( 2 NMABr).

[0101] Step 2: 2 NMABr (285.8 mg) and BiBr3 (269.0 mg) (molar ratio 1:1) were dissolved in anhydrous methanol (10 mL) to form a homogeneous 2 The NMA2BiBr5 precursor solution was stirred at 50°C for 1 h. The solvent was then removed by rotary evaporation and the yellow 2The NMA2BiBr5 product was vacuum dried at 50 °C for 12 h and ground using an agate mortar to obtain the final solid powder product.

[0102] Will 2 NMABr (28.6 mg) and BiBr3 (26.9 mg) (molar ratio of 1:1) were dissolved in 1.5 mL of anhydrous methanol and 0.5 mL of tetrahydrofuran. In order to control the growth rate of the crystals, they were placed in a sealed container with a small pore membrane to allow the saturated solution solvent to evaporate slowly to obtain the growing 2 NMA2BiBr5 single crystal. Fig.15 Shown 2 The crystal structure of NMA2BiBr5 single crystal is shown in the figure. 2 NMA2BiBr5 is composed of octahedral BiBr5 2- and 2 NMA + The cations are combined through strong interactions.

[0103] Fig.16 Shows the preparation 2 NMA2BiBr5 material powder XRD and its corresponding crystal simulation XRD. It can be seen from the figure that the peak position of the prepared material can correspond well to its crystal simulation XRD peak, indicating that the prepared material is consistent with its crystal structure and has good phase purity.

[0104] Fig.17 The halide perovskites DTABiBr4, TABiBr4, BTABiBr4, BOABiBr4 and BSABiBr4 regulated by different A-site cations were used as catalysts for the photocatalytic CO2 reduction products and reaction rates. The results showed that the prepared halide perovskites all have the ability to photocatalyze CO2 reduction, and the reduction products are CO and CH4, among which CO is the main product, accompanied by a small amount of CH4 product.

[0105] Fig.18 Demonstrated the halide perovskite PMA2BiBr5, 1 NMA2BiBr5 and 2 NMA2BiBr5 was used as a catalyst for the photocatalytic CO2 reduction products and reaction rate. The results showed that the prepared halide perovskites all have the ability to photocatalyze CO2 reduction, and the reduction products are CO and CH4, among which CO is the main product, accompanied by a small amount of CH4 product.

Claims

1. A method for preparing halide perovskite regulated by A-site cations, characterized in that: Follow the steps below to implement it: Step 1, mixing an organic amine with a solvent, adding an acid dropwise in an ice-water bath, stirring the obtained reaction mixture, and then removing the solvent with a rotary evaporator, rinsing the formed solid with dry ether, and vacuum drying to obtain the A-site cation; Step 2: dissolving the A-site cation and bismuth salt in a solvent, heating and stirring to form a uniform precursor solution, then removing the solvent with a rotary evaporator, vacuum drying, and grinding to obtain halide perovskites with different A-site cations.

2. The method for preparing the halide perovskite regulated by the A-site cation according to claim 1, characterized in that: In the step 1, the organic amine is specifically 4,5-dihydrothiazol-2-amine, 2-aminothiazole, 2-aminobenzothiazole, 2-aminobenzoxazole, 2-aminobenzoselenazole, benzylamine, 1-naphthylmethylamine, 2-(aminomethyl)naphthalene, 4-fluorobenzylamine, 4-chlorobenzylamine, 4-bromobenzylamine, 4-nitrobenzylamine, 4-(trifluoromethyl)benzylamine, 4-methylbenzylamine, 4-methoxybenzylamine, 3-fluorobenzylamine, 3-chlorobenzylamine, 3-bromobenzylamine, 3-nitrobenzylamine, 3-(trifluoromethyl)benzylamine, 3-methylbenzylamine, 3-methoxybenzylamine, 2-fluorobenzylamine, 2-chlorobenzylamine, 2-bromobenzylamine, 2-nitrobenzylamine, 2-(trifluoromethyl)benzylamine, 2-methylbenzylamine, and any one of 2-methoxybenzylamine.

3. The method for preparing the halide perovskite regulated by the A-site cation according to claim 1, characterized in that: In step 1, the solvent is anhydrous ethanol or anhydrous methanol; the acid is hydrobromic acid, and the molar ratio of the organic amine, the acid and the solvent is 1:1-1.2:10-20.

4. The method for preparing the halide perovskite regulated by A-site cations according to claim 1, characterized in that: In the step 1, the stirring time is 6-12 hours; the temperature during the removal of the solvent is 35-50° C., and the time is 0.5-1 hour; the vacuum drying temperature is 40-60° C., and the drying time is 8-12 hours.

5. The method for preparing the halide perovskite regulated by A-site cations according to claim 1, characterized in that: In the step 2, the A-site cation is 4,5-dihydrothiazol-2-amine hydrobromide, 2-aminothiazole hydrobromide, 2-aminobenzothiazole hydrobromide, 2-aminobenzoxazole hydrobromide, 2-aminobenzoselenazole hydrobromide, benzylamine hydrobromide, 1-naphthylmethylamine hydrobromide, 2-(aminomethyl)naphthalene hydrobromide, 4-fluorobenzylamine hydrobromide, 4-chlorobenzylamine hydrobromide, 4-bromobenzylamine hydrobromide, 4-nitrobenzylamine hydrobromide, 4-(trifluoromethyl)benzylamine hydrobromide, 4-methylbenzylamine hydrobromide , 4-methoxybenzylamine hydrobromide, 3-fluorobenzylamine hydrobromide, 3-chlorobenzylamine hydrobromide, 3-bromobenzylamine hydrobromide, 3-nitrobenzylamine hydrobromide, 3-(trifluoromethyl)benzylamine hydrobromide, 3-methylbenzylamine hydrobromide, 3-methoxybenzylamine hydrobromide, 2-fluorobenzylamine hydrobromide, 2-chlorobenzylamine hydrobromide, 2-bromobenzylamine hydrobromide, 2-nitrobenzylamine hydrobromide, 2-(trifluoromethyl)benzylamine hydrobromide, 2-methylbenzylamine hydrobromide, 2-methoxybenzylamine hydrobromide.

6. The method for preparing the halide perovskite regulated by A-site cations according to claim 1, characterized in that: In step 2, the bismuth salt is BiBr3; the solvent is anhydrous ethanol or anhydrous methanol; and the molar ratio of the A-site cation, the bismuth salt and the solvent is 1-2:1:5-10.

7. The method for preparing the halide perovskite regulated by A-site cations according to claim 1, characterized in that: In the step 2, the heating temperature is 40-60° C.; the stirring time is 0.5-1 h; the vacuum drying temperature is 40-60° C., and the vacuum drying time is 5-12 h.

8. The halide perovskite prepared by the method for preparing the halide perovskite regulated by A-site cations as described in any one of claims 1 to 7.

9. Use of the halide perovskite regulated by A-site cations as described in any one of claims 1 to 7 in photocatalytic carbon dioxide conversion.

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