An organic small molecule light absorber, its preparation method and application

Abstract

This invention belongs to the field of light-absorbing materials technology, and specifically relates to an organic small-molecule light absorber, its preparation method, and its applications. The molecular structure of the organic small-molecule light absorber is as follows: R1 is one of diphenylamine, carbazole, trifluoromethyl, methoxy, pyrrole, piperidine, furan, pyrazine, thiophene, and indole; R2 is one of triphenylamine, carbazole, triisopropylsilyne, trimethylsilyne, benzene, pyrrole, piperidine, furan, pyrazine, and thiophene. The preparation method involves mixing a diketone compound and an aromatic diamine compound in a solvent, followed by reflux heating under inert gas protection. This organic small-molecule light absorber can be used in interfacial solar-driven steam photothermal conversion, thermoelectric conversion, and cogeneration of hydropower.

Description

Technical Field

[0001] This invention belongs to the field of light-absorbing materials technology, and specifically relates to an organic small molecule light absorber, its preparation method, and its application. Background Technology

[0002] Currently, the scarcity of fossil fuels and water resources is a major global concern. Most power plants rely on coal or natural gas for electricity generation, but fossil fuels are not renewable resources. Therefore, finding renewable and sustainable photovoltaic or photothermal conversion materials can alleviate resource depletion to some extent. As we all know, solar energy is a renewable resource, and converting it into electricity or heat for daily use is a worthwhile area to explore.

[0003] Interfacial solar evaporation technology is a green, environmentally friendly, and sustainable technology. Compared with many traditional technologies, the emerging interfacial solar vapor generation (SISG) technology is considered one of the most promising methods to address the growing global water shortage. SISG technology relies on high-performance light absorbers to achieve photoelectric and photothermal conversion. These light absorbers mainly include carbon-based inorganic materials, metal-based inorganic materials, organic-polymers, organic-inorganic hybrid materials, organic eutectic materials, and pure organic small-molecule materials. The high thermal conductivity of carbon materials can lead to significant heat loss at the evaporation interface, while polymers and other materials, due to their complex structures and hydrophilicity, may result in low conversion efficiency and reduced thermal insulation performance. Pure organic small-molecule materials have attracted widespread attention due to their ease of structural manipulation, fine-tuning properties, and ease of processing. Molecular design plays a crucial role in achieving high photothermal conversion performance. Summary of the Invention

[0004] In response, this application provides an organic small molecule light absorber with the following molecular structure:

[0005]

[0006] R1 is one of diphenylamine, carbazole, trifluoromethyl, methoxy, pyrrole, piperidine, furan, pyrazine, thiophene, and indole.

[0007] R2 is one of triphenylamine, carbazole, triisopropylsilyne, trimethylsilyne, benzene, pyrrole, piperidine, furan, pyrazine, or thiophene.

[0008] As a preferred option: the molecular structure of the organic small molecule light absorber is as follows:

[0009]

[0010] This invention also provides a method for preparing the above-mentioned organic small molecule light absorber: a diketone compound and an aromatic diamine compound are mixed in a solvent, and then subjected to a reflux heating reaction under inert gas protection. After the reaction, the mixture is purified and separated.

[0011] Among them, the structure of diketone compounds is R1 is one of the following: diphenylamine, carbazole, trifluoromethyl, methoxy, pyrrole, piperidine, furan, pyrazine, thiophene, and indole.

[0012] The structure of aromatic diamine compounds is as follows: R2 is one of triphenylamine, carbazole, triisopropylsilyne, trimethylsilyne, benzene, pyrrole, piperidine, furan, pyrazine, or thiophene.

[0013] Preferably, the molar ratio of aromatic diamine compounds to diketone compounds is 1:0.5 to 2.

[0014] Preferably, the solvent is one or a mixture of several of acetic acid, tetrahydrofuran, and acetonitrile.

[0015] Preferably, the heating reaction time is 12–48 h.

[0016] As a preferred method, purification and separation are carried out by column chromatography.

[0017] This invention also provides an application of the above-mentioned small organic molecule light absorber in interfacial solar-driven steam photothermal conversion, thermoelectric conversion, and combined hydropower generation.

[0018] The beneficial effects of this application are as follows: Thiadiazole quinoxaline derivatives are generated by reacting the carbonyl group on a diketone compound with the amino group on an aromatic diamine compound. These derivatives can serve as conjugated electron donor-acceptor (DA) structures (the thiadiazole quinoxaline center is the electron acceptor portion, and the aromatic amine group is the electron donor portion). The formation of the DA structure results in less HOMO-LUMO overlap, making it easier to achieve similar energy levels between the excited state S1 and the triplet state T1, thereby reducing the band gap between S1 and T1, i.e., forming a smaller ΔE. st This enhances nonradiative decay and improves the photothermal conversion efficiency of the molecule. Furthermore, the DA-type structure extends absorption into the near-infrared region due to intramolecular charge transfer effects.

[0019] In addition, this scheme also influences the decay effect of molecules and enhances non-radiative decay by endowing the above-mentioned DA structure with freely rotating groups.

[0020] This application also considers that, in addition to fully satisfying the above two points, the overall hydrophilicity and hydrophobicity of the light-absorbing molecules must also be fully considered. Specifically, when the molecule is used as a light-absorbing and converting component in water resources, it must not only be able to make smooth contact with water, but also maintain an effective interface in the aquatic environment to ensure the effective absorption and utilization of light energy by the molecule. Therefore, when selecting "freely rotating groups," it is necessary to consider not only the free rotation capability of the group under the DA structure of this scheme, but also its influence on the overall hydrophilicity and hydrophobicity of the molecule. Moreover, the "group" here is not a single group, but includes both side groups attached to diketone compounds and side groups attached to aromatic amine compounds. It can be seen that, with so many factors to consider, the selection of groups becomes completely unpredictable, thus presenting significant selection difficulties. Through extensive theoretical prediction and experimental screening, this scheme ultimately found that the light absorbers of the structures in Examples 1 to 3 can better meet the above points, exert high efficiency in photothermal and photoelectric conversion, and are suitable for solar interface steam generation, thermoelectric generation, and cogeneration of hydropower. Attached Figure Description

[0021] Figure 1 The 1H NMR spectrum of the TPA-TQN organic small molecule light absorber prepared in Example 1;

[0022] Figure 2 The carbon NMR spectrum of the TPA-TQN organic small molecule light absorber prepared in Example 1;

[0023] Figure 3 This is a high-resolution mass spectrometry of the TPA-TQN organic small molecule light absorber prepared in Example 1;

[0024] Figure 4 The 1H NMR spectrum of the SiTPA-TQN organic small molecule light absorber prepared in Example 2;

[0025] Figure 5 The carbon NMR spectrum of the SiTPA-TQN organic small molecule light absorber prepared in Example 2;

[0026] Figure 6 High-resolution mass spectra of the SiTPA-TQN organic small molecule light absorber prepared in Example 2;

[0027] Figure 7 The 1H NMR spectrum of the PhTPA-TQN organic small molecule light absorber prepared in Example 3;

[0028] Figure 8 The carbon NMR spectrum of the PhTPA-TQN organic small molecule light absorber prepared in Example 3;

[0029] Figure 9High-resolution mass spectrometry of the PhTPA-TQN organic small molecule light absorber prepared in Example 3;

[0030] Figure 10 This is a scanning electron microscope image of TPA-TQN, an organic small molecule light absorber prepared in Example 1, coated on cellulose paper in Experiment 2.

[0031] Figure 11 The thermogravimetric analysis (TGA) charts of the organic small molecule light absorbers TPA-TQN, SiTPA-TQN, and PhTPA-TQN prepared in Examples 1, 2, and 3, respectively, show that the prepared organic small molecule light absorbers have ideal thermal stability.

[0032] Figure 12 The organic small molecule light absorbers TPA-TQN, SiTPA-TQN, and PhTPA-TQN prepared in Examples 1, 2, and 3, respectively, were tested at 1×10⁻⁶. -5 The absorption spectrum in the M CH2Cl2 solution shows that the prepared organic small molecule light absorber has high absorbency for visible light and also extends the absorption into the near-infrared region.

[0033] Figure 13 This is a temperature change graph of the organic small molecule light absorber TPA-TQN powder prepared in Example 1 under continuous solar irradiation for 30 minutes.

[0034] Figure 14 The organic small molecule light absorber TPA-TQN prepared in Example 1 was used in a 655nm laser at 0.8 kW·m. -2 The temperature change graphs during the five cyclic switching processes under irradiation demonstrate that the light absorber has ideal light stability.

[0035] Figure 15 Experiment 2 shows the mass change of water in cellulose paper supported by the organic small molecule light absorber TPA-TQN prepared in Example 1 under one continuous solar irradiation. The water evaporation efficiency reached 84.52%.

[0036] Figure 16 At different optical powers (1, 1.5, 2 kW·m) -2 Temperature change on the surface of the organic small molecule light absorber TPA-TQN prepared in Example 1 under (and darkness);

[0037] Figure 17 At different optical powers (1, 1.5, 2 kW·m) -2 Under conditions of darkness, the voltage generation curve of the organic small molecule light absorber TPA-TQN prepared in Example 1 is shown.

[0038] Figure 18This is a schematic diagram showing the stability of thermoelectric conversion performance during three on / off processes when using the organic small molecule light absorber TPA-TQN prepared in Example 1 as the light absorber of the thermoelectric device.

[0039] Figure 19 This is a schematic diagram of the apparatus for Experiment 2;

[0040] Figure 20 This is a schematic diagram of the apparatus for Experiment 3. Detailed Implementation

[0041] A method for preparing an organic small molecule light absorber:

[0042] Diketone compounds and aromatic diamine compounds were mixed in a solvent and then subjected to reflux and heating under inert gas protection. After the reaction, the mixture was purified and separated.

[0043] Among them, the structure of diketone compounds is R1 is one of the following: diphenylamine, carbazole, trifluoromethyl, methoxy, pyrrole, piperidine, furan, pyrazine, thiophene, and indole.

[0044] The structure of aromatic diamine compounds is as follows: R2 is one of triphenylamine, carbazole, triisopropylsilyne, trimethylsilyne, benzene, pyrrole, piperidine, furan, pyrazine, and thiophene.

[0045] The molar ratio of aromatic diamines to diketones is 1:0.5–2.

[0046] The solvent is one or a mixture of several of acetic acid, tetrahydrofuran, and acetonitrile.

[0047] The heating reaction time is 12–48 hours.

[0048] The particles were purified and separated by column chromatography.

[0049] Specific examples are as follows:

[0050] Example 1

[0051] Aromatic diamine TPANH2 (204 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, then cooled to room temperature (25 °C). The reaction system was then poured into methanol, and the solvent was evaporated under reduced pressure. The pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. Elution was performed with dichloromethane-n-hexane (1:1 v / v). The eluent was evaporated to dryness to obtain the purple solid TPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0052]

[0053] The proton NMR spectrum, carbon NMR spectrum, and high-resolution mass spectra of the prepared product are as follows: Figure 1 , Figure 2 , Figure 3 As shown.

[0054] Example 2

[0055] Aromatic diamine SiNH2 (137 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, a 5% (w / w) NaOH aqueous solution was added to adjust the pH of the product to neutral. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid SiTPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0056]

[0057] The proton NMR spectrum, carbon NMR spectrum, and high-resolution mass spectra of the prepared product are as follows: Figure 4 , Figure 5 , Figure 6 As shown.

[0058] Example 3

[0059] Aromatic diamine PhNH2 (98 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, a 5% (w / w) NaOH aqueous solution was added to adjust the pH of the product to neutral. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a red solid PhTPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0060]

[0061] The proton NMR spectrum, carbon NMR spectrum, and high-resolution mass spectra of the prepared product are as follows: Figure 7 , Figure 8 , Figure 9 As shown.

[0062] Example 4

[0063] Aromatic diamine FNH2 (110 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, the pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a red solid FTPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0064]

[0065] Example 5

[0066] Aromatic diamine ClNH2 (120 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed and heated under nitrogen atmosphere for 24 hours. After cooling to room temperature, the reaction system was poured into methanol. The solvent was evaporated under reduced pressure, and the pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. The eluent was dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a red solid ClTPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0067]

[0068] Example 6

[0069] Aromatic diamine CH3NH2 (107 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed and heated under nitrogen atmosphere for 24 hours. After cooling to room temperature, the reaction system was poured into methanol. The solvent was evaporated under reduced pressure, and the pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. The eluent was dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid CH3TPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0070]

[0071] Example 7

[0072] Aromatic diamine t-BuNH2 (133 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed and heated under nitrogen atmosphere for 24 hours. After cooling to room temperature, the reaction system was poured into methanol. The solvent was evaporated under reduced pressure, and the pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid t-BuTPA-TQN organic small molecule light absorber. The reaction formula is as follows:

[0073]

[0074] Example 8

[0075] Aromatic diamine OHNH2 (109 mg, 0.31 mmol) and (1,2-bis(4-(diphenylamine)phenyl)ethane-1,2-dione) (TPACO, 170 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, a 5% (w / w) NaOH aqueous solution was added to adjust the pH of the product to neutral. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid, OHTPA-TQN, an organic small molecule light absorber. The reaction formula is as follows:

[0076]

[0077] Example 9

[0078] Aromatic diamine TPANH2 (204 mg, 0.31 mmol) and (1,2-bis(4-(carbazole)phenyl)ethane-1,2-dione) (CZCO, 167.6 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, a 5% (w / w) NaOH aqueous solution was added to adjust the pH of the product to neutral. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid TPA-CQN organic small molecule light absorber. The reaction formula is as follows:

[0079]

[0080] Example 10

[0081] Aromatic diamine TPANH2 (204 mg, 0.31 mmol) and (1,2-bis(4-(piperidinyl)phenyl)ethane-1,2-dione (PIPCO, 116.7 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed and heated under nitrogen atmosphere for 24 hours. After cooling to room temperature, the reaction system was poured into methanol. The solvent was evaporated under reduced pressure, and the pH of the product was adjusted to neutral by adding 5% NaOH aqueous solution. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid TPA-PQN organic small molecule light absorber. The reaction formula is as follows:

[0082]

[0083] Example 11

[0084] Aromatic diamine TPANH2 (204 mg, 0.31 mmol) and (1,2-bis(4-(pyrrole)phenyl)ethane-1,2-dione (PyCO, 105.5 mg, 0.31 mmol) were placed in a 50 mL Shrek flask, followed by the addition of 20 mL of acetic acid solution. The resulting mixture was refluxed under nitrogen atmosphere for 24 hours, cooled to room temperature, and then poured into methanol. After evaporating the solvent under reduced pressure, a 5% (w / w) NaOH aqueous solution was added to adjust the pH of the product to neutral. The product was extracted, and the crude product was purified by column chromatography. The product was eluted with dichloromethane-n-hexane (1:1 v / v), and the eluent was evaporated to dryness to obtain a black solid TPA-PyQN organic small molecule light absorber. The reaction formula is as follows:

[0085]

[0086] Experiment 1

[0087] Five mg each of the organic small molecule light absorber powders (TPA-TQN, SiTPA-TQN, PhTPA-TQN, FTPA-TQN, ClTPA-TQN, CH3TPA-TQN, t-BuTPA-TQN, OHTPA-TQN, TPA-CQN, TPA-PQN, TPA-PyQN) obtained in the above embodiments were dispersed in small beakers containing 1 ml of water (the beakers were wrapped with foam as insulation material). The dispersions were irradiated with a 300W xenon lamp to simulate sunlight for 20 minutes, and the temperatures of the water and organic small molecule light absorber powders before and after irradiation were recorded using a thermal imaging camera.

[0088] When a dispersion containing small-molecule organic light absorber powder is exposed to light, the temperature generally rises significantly, indicating that the small-molecule organic light absorber powder has photothermal conversion properties. For example, [the following text appears to be unrelated and possibly a separate sentence fragment: "attached"] Figure 13 In the process, the temperature of the TPA-TQN dispersion rose to 40°C within 30 seconds.

[0089] Calculate the photothermal conversion efficiency (η) based on the temperature recorded by the thermal imaging camera:

[0090]

[0091] Where Q is the generated heat energy (i.e., Q = Q1 - Q2), and Q1 is the heat energy generated by TPA-TQN, SiTPA-TQN, PhTPA-TQN, FTPA-TQN, ClTPA-TQN, CH3TPA-TQN, t-BuTPA-TQN, OHTPA-TQN, TPA-CQN, TPA-PQN, and TPA-PyQN, which is determined by the mass m of the organic small molecule light absorber powder, the temperature difference ΔT1 before and after irradiation, and the specific heat capacity C of the organic small molecule light absorber powder.

[0092] Q1=CmΔT1=CρvΔT1

[0093] Q2 represents the heat energy generated by the dispersant water, which is determined by the mass m of the dispersant water, the temperature difference ΔT2 before and after irradiation, and the specific heat capacity C of pure water.

[0094] Q2=CmΔT2=CρVΔT2

[0095] E is the total energy of the incident light, which is determined by the incident light power P, the irradiated area S, and the irradiation time t.

[0096] ε=PSt

[0097] The calculation results are shown in Table 1:

[0098] Table 1

[0099]

[0100] As shown in Table 1, the photothermal conversion efficiency of the light absorbers in Examples 1 to 3 is significantly higher than that in other examples. It can be seen that once the groups extended on the DA structure can achieve a good balance between the rotation ability of the groups and the hydrophilicity and hydrophobicity of the entire molecule, the efficiency of their use can be significantly higher than that of other structures of this type of light absorber.

[0101] Experiment 2

[0102] Five mg each of the organic small molecule light absorber powders (TPA-TQN, SiTPA-TQN, PhTPA-TQN, FTPA-TQN, ClTPA-TQN, CH3TPA-TQN, t-BuTPA-TQN, OHTPA-TQN, TPA-CQN, TPA-PQN, TPA-PyQN) obtained in the above embodiments were dispersed in 0.3 mL of water. The resulting dispersions were then evenly coated onto cellulose paper discs with a diameter of 2 cm (using up all the dispersion). The cellulose paper disc is laid flat and placed directly opposite the mouth of a beaker. The circumference of the cellulose paper disc is sealed to the rim of the beaker, providing support and fixation. The beaker is filled with water to half its volume (sufficient water). A portion of the cellulose paper disc extends downwards along its edge, plunging into the water to continuously absorb water. Simultaneously, a simulated light source is positioned directly above the cellulose paper disc, continuously illuminating it. This establishes a solar evaporator model (see attached diagram for specific experimental setup). Figure 19 The water loss after 60 minutes of continuous irradiation was weighed using a balance to determine the solar energy conversion efficiency η during the photothermal assisted water evaporation process. The calculation formula is as follows:

[0103]

[0104] In the formula, m is the mass flux of water (evaporation rate);

[0105] h LV The total liquid-vapor phase transition enthalpy, i.e., sensible heat and vaporization enthalpy, h LV =Q+Δh vap Q is the energy provided to heat the system from the initial temperature to the final temperature, and Δh is the energy required. vap This refers to the enthalpy change of water vaporization.

[0106] Q = c liquid ×(T-T0)

[0107] Δh vap =Q1+Δh 100 +Q2

[0108] Q1 = C liquid ×(100-T)

[0109] Q2 = C vapor ×(T-100)

[0110] T0 is the initial temperature of the water.

[0111] T1 is the temperature of the water after irradiation.

[0112] C liquid The specific heat capacity of liquid water,

[0113] C vapor The specific heat capacity of water vapor.

[0114] Δh 100 The vaporization enthalpy change of water at 100 degrees Celsius is 2260 kJ / kg.

[0115] P0 is 1kW·m -2 The nominal solar irradiance value,

[0116] C opt This refers to light concentration.

[0117] The calculation results are shown in Table 2:

[0118] Table 2

[0119]

[0120] As shown in Table 2, the light absorbers with structures from Examples 1 to 3 exhibited significantly higher conversion efficiencies than other examples when used in photothermal assisted water evaporation experiments. In Example 1, the efficiency even exceeded 80%, a level rarely achieved in the industry. Therefore, it also demonstrates a clear advantage in the degree of water evaporation (to obtain pure water). (See attached table.) Figure 15 The results show the changes in the mass of the water used in the experiment when the organic small molecule light absorber TPA-TQN loaded onto cellulose paper prepared in Example 1 was used in Experiment 2.

[0121] Experiment 3

[0122] Since the temperature difference between circulating water and the surface of thermoelectric equipment can generate electrical energy, this invention studies the thermoelectric conversion process. Based on the Seebeck effect, this invention establishes a suitable thermoelectric device for electricity collection (see appendix for specific experimental setup). Figure 20 ).

[0123] At different optical powers (1, 1.5, 2 kW·m) -2 Under conditions of darkness, the temperature changes of water and light absorber surfaces are collected, and the electrical energy generated by the temperature difference between the circulating water and the light absorber surfaces is harvested. (2kW·m) -2 Under these conditions, the temperature difference (ΔT(T2-T1)) between the circulating water and the surface of the solar absorbers of PhTPA-TQN, SiTPA-TQN and TPA-TQN is as high as 20℃, 8℃ and 14℃, respectively.

[0124] As attached Figure 18 As shown, the stable voltage increases with increasing optical density at 1.0, 1.5, and 2.0 kW·m. -2 Under simulated sunlight, the electrical energy generated by the temperature difference between the circulating water and the TPA-TQN surface reached 130mV, 180mV, and 250mV, respectively.

[0125] Experiment 4

[0126] The organic small molecule light absorber powders (TPA-TQN, SiTPA-TQN, PhTPA-TQN, FTPA-TQN, ClTPA-TQN, CH3TPA-TQN, t-BuTPA-TQN, OHTPA-TQN, TPA-CQN, TPA-PQN, TPA-PyQN) obtained in the above embodiments were tested using a combined hydropower experimental device.

[0127] During the water evaporation process, the water evaporation rates of the three light absorbers, PhTPA-TQN, SiTPA-TQN, and TPA-TQN, reached 0.89, 0.71, and 0.92 kg·m³, respectively. -2 ·h -1 The evaporation efficiencies were 61.37%, 49.50%, and 63.95%, respectively.

[0128] During thermoelectric conversion, the three light absorbers PhTPA-TQN, SiTPA-TQN, and TPA-TQN exhibit a light absorption capacity of 2 kW·m⁻¹. -2 After 30 minutes of irradiation, the voltage increased to a relatively stable voltage of 110mV, 108mV and 105mV respectively.

[0129] These results demonstrate that the light absorber of the present invention exhibits good overall performance in the combined production of solar steam and power generation.

Claims

1. An organic small-molecule light absorber characterized by: The molecular structure is 。 2. A method for preparing the organic small molecule light absorber as described in claim 1, characterized in that: The preparation method is as follows: mixing a diketone compound and an aromatic diamine compound in a solvent, then performing a reflux heating reaction under inert gas protection, and then performing purification and separation after the reaction, The structure of the diketone compound is The structure of the aromatic diamine compound is 。 3. The method for preparing the organic small molecule light absorber as described in claim 2, characterized in that: The molar ratio between the aromatic diamine compound and the diketone compound is 1:0.5-2.

4. The method for preparing the organic small molecule light absorber as described in claim 2, characterized in that: The solvent is one or a mixture of several of acetic acid, tetrahydrofuran and acetonitrile.

5. The method for preparing the organic small molecule light absorber as described in claim 2, characterized in that: The heating reaction time is 12-48 h.

6. The method for preparing the organic small molecule light absorber as described in claim 2, characterized in that: Purification and separation are performed by column chromatography.

7. Application of the organic small-molecule light absorber in claim 1 to interface solar energy-driven steam light-heat conversion, thermoelectric conversion and combined production of power and water.

Images