Process for the preparation of dff from hmf based on the oxidation of sulfides by anderson-type polyoxometalates under load

Abstract

The application discloses a method for preparing DFF by oxidizing HMF based on a load Anderson type polyoxometalate sulfide, and specifically comprises the following steps: 1, preparing an Anderson type polyoxometalate loaded multi-metal sulfide; 2, adding HMF solution, and performing a photocatalytic oxidation experiment under light conditions. The method solves the problem of low catalytic efficiency in catalytic oxidation of HMF caused by high electron hole rate and short service life of ZnIn2S4 material by using a heteropoly acid loaded ZnIn2S4-SnIn4S8 material. The process can not only efficiently synthesize DFF (selectivity reaches 98%) but also has mild reaction conditions and simple operation, and is a cheap and efficient DFF preparation method, which provides a reference for renewable biomass resource conversion and has important significance for development of new renewable energy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical technology, and relates to a method for preparing DFF by oxidizing HMF based on a sulfide loaded with an Anderson-type polyoxometalate, in particular, a method for preparing 2,5-furandicarboxaldehyde (DFF) by catalytically oxidizing 5-hydroxymethylfurfural (HMF) using a multi-metal sulfide SnIn4S8-ZnIn2S4 (SZIS) loaded with an Anderson-type polyoxometalate. BACKGROUND

[0002] Energy shortage and environmental pollution are two important problems faced by human beings and have attracted extensive attention of researchers worldwide. Photocatalysis technology has been considered to have great potential in solving energy and environmental problems. Biomass is a renewable energy and material resource, and among various biomass resources and intermediates, 5-hydroxymethylfurfural (HMF) derived from C6 monosaccharide is considered as a key platform molecular compound, which can produce a variety of industrially important molecules through further conversion. 2,5-diformylfuran (DFF), as one of the oxidation products of HMF, is of great concern because it can be used to synthesize medicines, functional polymers and bactericides. The traditional DFF production process has problems such as low selectivity, high energy consumption, environmental pollution, etc., and the traditional catalysts mostly choose noble metals, need strong oxidants or high-pressure oxygen, and are carried out under high temperature and strong base conditions, which may produce toxic waste. Therefore, the development of a green and pollution-free HMF catalytic oxidation system to avoid the use of toxic chemicals (substrates or organic solvents) and the development of a high-selectivity non-noble metal catalyst undoubtedly meet the sustainable development of the chemical industry. Multiple metal sulfides have attracted more and more attention in the field of photocatalysis due to their excellent photoelectron properties, but the problems of low photo-generated carrier separation efficiency and poor light stability need to be solved. SUMMARY

[0003] To solve the above technical problems, the present application provides a method for preparing DFF by oxidizing HMF based on a sulfide loaded with an Anderson-type polyoxometalate, in particular, a method for preparing DFF based on SnIn4S8-ZnIn2S4 loaded with an Anderson-type polyoxometalate.

[0004] The technical solution of the present application to solve the above technical problems is as follows:

[0005] The method for preparing DFF based on SnIn4S8-ZnIn2S4 loaded with an Anderson-type polyoxometalate comprises the following steps:

[0006] 1) preparing SnIn4S8-ZnIn2S4 loaded with an Anderson-type polyoxometalate:

[0007] Step 1.1) ZnCl2, InCl3·4H2O and C2H5NS were dispersed into deionized water, stirred at room temperature for 20-40 min, then transferred into a reaction kettle, and reacted at 200-220 ℃ until the reaction was completed. After cooling, washing and drying overnight, ZnIn2S4 was obtained.

[0008] The molar ratio of ZnCl2, InCl3·4H2O and C2H5NS is 1:2:6.

[0009] Step 1.2) ZnIn2S4 was ultrasonically dispersed into anhydrous ethanol, SnCl4·5H2O and InCl3·4H2O were added, stirred at room temperature until complete dispersion, then TAA was added, stirred until complete dissolution, and dried overnight to grow in situ to obtain SnIn4S8-ZnIn2S4 (SZIS),

[0010] The molar ratio of ZnIn2S4, SnCl4·5H2O, InCl3·4H2O and TAA is 1:0.1-0.5:0.4-2:1.2-6.

[0011] Step 1.3) 5-40% of Anderson-type heteropoly acid salt was added to the mass of SZIS, heated to 70-80 ℃ until the reaction was completed, then cooled to room temperature, and the yellow-brown powder was collected by centrifugation, washed and dried to obtain SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate (ZnMo6-SZIS); wherein the Anderson-type heteropoly acid salt is any one of (NH4)3H6CoMo6O 24 , (NH4)4H6CuMo6O 24 , Na3H6FeMo6O 24 , Na5IMo6O 24 , (NH4)4ZnMo6O 24 .

[0012] 2) Dark reaction: SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate was added to an aqueous HMF solution, wherein the mass ratio of SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate to HMF was 1-5:1.

[0013] Then, it was placed in a photocatalytic reactor under the conditions of 0-40 o C, light shielding, and circulating water, and stirred for 0.2-1 h to reach adsorption equilibrium.

[0014] 3) Photocatalytic reaction: under light conditions, the catalytic oxidation reaction was carried out for 1-6 h to obtain 2,5-furandicarboxaldehyde (DFF).

[0015] Preferably, the dark reaction time is 0.5 h and the photocatalytic reaction time is 3 h.

[0016] Preferably, the illumination conditions are one of ultraviolet light, visible light, and ultraviolet-visible light.

[0017] The significant improvement in selectivity of the photocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxaldehyde (DFF) in this invention lies in the fact that the multi-metal sulfide supported on Anderson-type polyoxometalate salts has a lower recombination rate and a longer lifetime of photocarriers, which facilitates charge transfer and thus significantly enhances its redox ability for 5-hydroxymethylfurfural (HMF). Taking Example 1, which exhibits the best selectivity, as an example, the heteropolyacid (NH4)4ZnMo6O is introduced. 24 Afterwards, ZnMo6-SZIS as Figure 8 As shown, UV-vis light absorption tests reveal that the multi-metal sulfides loaded with Anderson-type polyoxometalates exhibit significantly improved light absorption range and intensity; furthermore, as... Figure 9 PL testing showed that ZnMo6-SZIS had the lowest photoluminescence intensity. Figure 10 The EIS results showed that ZnMo6-SZIS possessed the lowest charge transfer impedance, demonstrating that in the photocatalytic HMF-to-DFF preparation method of this invention, the recombination probability of photogenerated electrons and holes on the surface of 10% ZnMo6-SZIS is the lowest. The lowest charge transfer impedance is more conducive to the transfer of photogenerated electrons, thus enabling effective electron-hole separation and significantly improving the selectivity of the photocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxaldehyde (DFF). Furthermore, experimental results also demonstrated that under optimal reaction conditions, the photocatalytic method of this invention can increase the DFF selectivity to 98%, nearly achieving the goal of partially and completely oxidizing HMF to DFF. Beneficial effects

[0018] (1) This invention provides a new catalytic system, namely, the coupling of Anderson-type heteropolyacid salt with SnIn4S8-ZnIn2S4 (SZIS) is effectively applied to the catalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxaldehyde.

[0019] (2) The y% ZnMo6-x% SnIn4S8-ZnIn2S4 of the present invention has a stronger light absorption range and a lower carrier recombination rate, exhibiting superior photocatalytic performance.

[0020] (3) The HMF selective oxidation of the present invention is effective under light conditions.

[0021] (4) The HMF selective oxidation reaction time of the application is short, and 98% of DFF selectivity can be achieved in 6 hours.

[0022] (5) The process of the application can synthesize DFF with high selectivity (selectivity up to 98%), and the process is simple to operate, mild in reaction conditions, high in selectivity, low in cost, green and pollution-free, and is a cheap and efficient method for preparing DFF. The application provides a reference for the conversion of renewable biomass resources and provides a new idea for the development of new renewable energy. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solutions of the application, and constitute a part of the specification, and together with the specific embodiments of the application, are used to explain the technical solutions of the application, and do not constitute a limitation on the technical solutions of the application.

[0024] Figure 1 The figure is a comparison chart of the HMF selective oxidation effect of ZnMo6-SZIS of the application embodiment 1. Reaction conditions: 10mL (0.03 g) 5-hydroxymethylfurfural aqueous solution, m(cat)=0.03 g, 30℃, 3h.

[0025] Figure 2 The figure is a comparison chart of the HMF selective oxidation effect of CoMo6-SZIS of the application embodiment 2. Reaction conditions: 10mL (0.03 g) 5-hydroxymethylfurfural aqueous solution, m(cat)=0.03 g, 30℃, 3h.

[0026] Figure 3 The figure is a comparison chart of the HMF selective oxidation effect of CuMo6-SZIS of the application embodiment 3. Reaction conditions: 10mL (0.03 g) 5-hydroxymethylfurfural aqueous solution, m(cat)=0.03 g, 30℃, 3h.

[0027] Figure 4 The figure is a comparison chart of the HMF selective oxidation effect of FeMo6-SZIS of the application embodiment 4. Reaction conditions: 10mL (0.03 g) 5-hydroxymethylfurfural aqueous solution, m(cat)=0.03 g, 30℃, 3h.

[0028] Figure 5 The figure is a comparison chart of the HMF selective oxidation effect of IMo6-SZIS of the application embodiment 5. Reaction conditions: 10mL (0.03 g) 5-hydroxymethylfurfural aqueous solution, m(cat)=0.03 g, 30℃, 3h.

[0029] Figure 6 The figure is an XRD test chart of ZnMo6-SZIS of the application embodiment 1.

[0030] Figure 7 The electron microscope images of ZnMo6-SZIS of Example 1 of the present application. Wherein, (A) ZnIn2S4 transmission electron microscope, (B) 30% SZIS transmission electron microscope, (C) 10% ZnMo6-SZIS transmission electron microscope, (D-E) high magnification transmission electron microscope, (F) electron diffraction, (G) elemental dispersion map.

[0031] Figure 8 The UV-vis test image of ZnMo6-SZIS of Example 1 of the present application.

[0032] Figure 9 The PL test image of ZnMo6-SZIS of Example 1 of the present application.

[0033] Figure 10 The EIS test image of ZnMo6-SZIS of Example 1 of the present application. DETAILED DESCRIPTION

[0034] The principles and features of the present application are described below, and the examples are only used to explain the present application, and are not used to limit the scope of the present application.

[0035] Example 1 ZnMo6-SZIS

[0036] (1) 1 mmol ZnCl2, 2 mmol InCl3·4H2O and 6 mmol C2H5NS were dispersed into 30 mL deionized water, stirred at room temperature for 30 min, transferred into a 50 mL polytetrafluoroethylene reactor at 220 ℃ for 12 h, washed with water and ethanol alternately several times after cooling, and dried overnight to obtain ZnIn2S4.

[0037] (2) 0.5 mmol of ZnIn2S4 was ultrasonically dispersed into 50 mL anhydrous ethanol. Then, 0.05 mmol SnCl4·5H2O and 0.2 mmol InCl3·4H2O were added. After stirring at room temperature for 30 min, 0.6 mmol TAA was added to the mixture, and stirred for 30 min to completely dissolve, to obtain 10% SnIn4S8-ZnIn2S4 (SZIS).

[0038] (3) (NH4)3H6CoMo6O 24The solution was finally transferred into a 100 mL round bottom flask and heated to 75 °C for 3 h. The reaction suspension was naturally cooled to room temperature and the yellow-brown powder was collected by centrifugation. The powder was washed with deionized water and anhydrous ethanol alternately for 3 times and dried under vacuum at 60 °C overnight.

[0039] The prepared composite sample was labeled as 10% ZnMo6-SZIS. The crystal structure of 10% ZnMo6-SZIS was analyzed by XRD, Figure 6 The crystal structure of 10% ZnMo6-SZIS was analyzed by XRD, Figure 7 The element analysis in EDS by SEM showed the successful loading of ZnMo6, Figure 7 The electron diffraction pattern of (F) showed the successful synthesis of SnIn4S8 and ZnIn2S4.

[0040] (4) Photocatalytic oxidation reaction

[0041] 1) Dark reaction: 0.03 g of 10% ZnMo6-SZIS was added to the HMF (0.03 g) aqueous solution, and then placed in a photocatalytic reactor for 0~40 o C, light shielding, and circulating water conditions for 1 h to reach adsorption equilibrium;

[0042] 2) Photocatalytic reaction: under visible light irradiation, the catalytic oxidation reaction was carried out for 6 h to obtain 2,5-furandicarboxaldehyde (DFF). The results showed that the DFF selectivity of 10% ZnMo6-SZIS was 98%.

[0043] 3) When the loading amount of Anderson-type heteropolyacid salt CoMo6 was appropriately adjusted, the visible light catalytic oxidation DFF selectivity was better than that of ZnIn2S4, as shown in Table 1, the DFF selectivity of 5% and 40% ZnMo6 loading was 80% and 83%, which was much higher than that of ZnIn2S4. Figure 1

[0044] Example 2 CoMo6-SZIS

[0045] (1) 1 mmol of ZnCl2, 2 mmol of InCl3·4H2O, and 6 mmol of C2H5NS were dispersed into 30 mL of deionized water, stirred at room temperature for 30 min, transferred into a 50 mL polytetrafluoroethylene reaction kettle at 220 °C for 12 h, washed with water and ethanol alternately several times after cooling, and dried overnight to obtain ZnIn2S4.

[0046] ​(2) 0.5 mmol of ZnIn2S4 was ultrasonically dispersed in 50 mL of anhydrous ethanol. Then, 0.1 mmol of SnCl4·5H2O and 0.4 mmol of InCl3·4H2O were added. After stirring at room temperature for 30 min, 1.2 mmol of TAA was added to the mixture, and stirring was performed for 30 min to completely dissolve it, obtaining 20% SnIn4S8-ZnIn2S4.

[0047] (3) (NH4)3H6CoMo6O 24 Stirring was continued for 30 min. The solution was finally transferred to a 100 mL round-bottom flask, heated to 75 °C, and maintained for 3 h. After the reaction, the suspension was naturally cooled to room temperature, and a yellow-brown powder was collected by centrifugation. Washing was performed three times with deionized water and anhydrous ethanol alternately, and drying was performed under vacuum at 60 °C overnight, obtaining the product. The prepared composite sample was marked as 15% CoMo6-SZIS.

[0048] (4) Photocatalytic oxidation reaction

[0049] 1) Dark reaction: 0.03 g of 15% CoMo6-SZIS was added to an aqueous solution of HMF (0.03 g), and then placed in a photocatalytic reactor to stir for 1 h under the conditions of 0~40 o C, light shielding, and circulating water to reach adsorption equilibrium;

[0050] 2) Photocatalytic reaction: after 3 h of catalytic oxidation under visible light, 2,5-furandicarboxaldehyde (DFF) was obtained. As shown in Figure 2 The results show that the DFF selectivity of 15% CoMo6-SZIS is 87%.

[0051] 3) When the loading amount of Anderson-type heteropoly acid salt CoMo6 is appropriately adjusted, the visible light catalytic oxidation DFF selectivity is better than that of ZnIn2S4, as shown in Figure 2 The DFF selectivities of 5% and 40% CoMo6 loadings are 82% and 79%, respectively.

[0052] Example 3 CuMo6-SZIS

[0053] (1) 1 mmol of ZnCl2, 2 mmol of InCl3·4H2O, and 6 mmol of C2H5NS were dispersed in 30 mL of deionized water, stirred at room temperature for 30 min, transferred to a 50 mL polytetrafluoroethylene reactor, and reacted at 220 °C for 12 h. After cooling, washing was performed several times with water and ethanol alternately, and drying was performed overnight, obtaining ZnIn2S4.

[0054] (2) 0.5 mmol of ZnIn2S4 was ultrasonically dispersed in 50 mL of anhydrous ethanol. Then, 0.075 mmol of SnCl4·5H2O and 0.3 mmol of InCl3·4H2O were added. After stirring at room temperature for 30 min, 0.9 mmol of TAA was added to the mixture, and stirring was performed for 30 min to completely dissolve it, obtaining 15%SnIn4S8-ZnIn2S4.

[0055] (3) (NH4)4H6CuMo6O 24 Stirring was continued for 30 min. The solution was finally transferred to a 100 mL round-bottom flask, heated to 75 °C, and maintained for 3 h. After the reaction, the suspension was naturally cooled to room temperature, and a yellow-green powder was collected by centrifugation. Washing was performed three times with deionized water and anhydrous ethanol alternately, and vacuum drying was performed at 60 °C overnight to obtain the product. The prepared composite sample was marked as 10% CuMo6-SZIS.

[0056] (4) Photocatalytic oxidation reaction

[0057] 1) Dark reaction: 0.03 g of 10% CuMo6-15% SZIS was added to an aqueous solution of HMF (0.03 g), and then placed in a photocatalytic reactor for 0~40 o C, under the conditions of light shielding and circulating water, and stirring was performed for 1 h to reach adsorption equilibrium;

[0058] 2) Photocatalytic reaction: under the irradiation of visible light, a catalytic oxidation reaction was performed for 3 h to obtain 2,5-furandicarboxaldehyde (DFF). As shown in Figure 3 The results show that the DFF selectivity of 30% CuMo6-10% SZIS is 90%.

[0059] 3) When the loading amount of Anderson-type heteropoly acid salt CuMo6 is appropriately adjusted, as shown in Figure 3 the selectivity of visible light catalytic oxidation of DFF is better than that of ZnIn2S4.

[0060] Example 4 FeMo6-SZIS

[0061] (1) 1 mmol of ZnCl2, 2 mmol of InCl3·4H2O, and 6 mmol of C2H5NS were dispersed in 30 mL of deionized water, stirred at room temperature for 30 min, transferred to a 50 mL polytetrafluoroethylene reactor, and reacted at 220 °C for 12 h. After cooling, washing was performed several times with water and ethanol alternately, and drying was performed overnight to obtain ZnIn2S4.

[0062] (2) 0.5 mmol of ZnIn2S4 was ultrasonically dispersed in 50 mL of anhydrous ethanol. Then, 0.15 mmol of SnCl4·5H2O and 0.6 mmol of InCl3·4H2O were added. After stirring at room temperature for 30 min, 1.8 mmol of TAA was added to the mixture, and it was stirred for 30 min to completely dissolve, obtaining 30% SnIn4S8-ZnIn2S4.

[0063] (3) Na3H6FeMo6O 24 was added in an amount of 25% of the mass of the SZIS of step (2). The solution was stirred for 30 min. The solution was finally transferred to a 100 mL round-bottom flask and heated to 75 °C for 3 h. After the reaction, the suspension was naturally cooled to room temperature, and the yellow-brown powder was collected by centrifugation. The powder was washed with deionized water and anhydrous ethanol alternately for 3 times and dried under vacuum at 60 °C overnight to obtain the product. The prepared composite sample was marked as 25% FeMo6-SZIS.

[0064] (4) Photocatalytic oxidation reaction

[0065] 1) Dark reaction: 0.03 g of 25% FeMo6-30% SZIS was added to an aqueous solution of HMF (0.03 g), and then placed in a photocatalytic reactor for 0~40 o C, under the conditions of light shielding and circulating water, and stirred for 1 h to reach adsorption equilibrium;

[0066] 2) Photocatalytic reaction: under the irradiation of visible light, the catalytic oxidation reaction was carried out for 3 h to obtain 2,5-furandicarboxaldehyde (DFF). As Figure 4 The results show that the selectivity of DFF of 25% FeMo6-SZIS is 83%.

[0067] 3) When the loading amount of Anderson-type heteropolyacid salt FeMo6 is appropriately adjusted, as shown in Table 1, the selectivity of visible light catalytic oxidation of DFF is better than that of ZnIn2S4. Figure 4

[0068] Example 5 IMo6-SZIS

[0069] (1) 1 mmol of ZnCl2, 2 mmol of InCl3·4H2O and 6 mmol of C2H5NS were dispersed in 30 mL of deionized water, stirred at room temperature for 30 min, transferred to a 50 mL polytetrafluoroethylene reaction kettle, and reacted at 220 °C for 12 h. After cooling, the product was washed with water and ethanol alternately for several times and dried overnight to obtain ZnIn2S4.

[0070] ​(2) 0.5 mmol of ZnIn2S4 was ultrasonically dispersed in 50 mL of anhydrous ethanol. Then, 0.125 mmol of SnCl4·5H2O and 0.5 mmol of InCl3·4H2O were added. After stirring at room temperature for 30 min, 1.5 mmol of TAA was added to the mixture, and it was stirred for 30 min to completely dissolve, obtaining 25% SnIn4S8-ZnIn2S4.

[0071] (3) Na5IMo6O 24 was added in an amount of 10% of the mass of the SZIS of step (2). The solution was stirred for 30 min. The solution was finally transferred to a 100 mL round-bottom flask and heated to 75 °C for 3 h. After the reaction, the suspension was naturally cooled to room temperature, and a yellow-brown powder was collected by centrifugation. The powder was washed three times with deionized water and anhydrous ethanol alternately and dried under vacuum at 60 °C overnight to obtain the product. The prepared composite sample was marked as 10% IMo6-SZIS.

[0072] (4) Photocatalytic oxidation reaction

[0073] 1) Dark reaction: 0.03 g of 10% IMo6-25% SZIS was added to an aqueous solution of HMF (0.03 g), and then placed in a photocatalytic reactor for 0~40 o h of stirring under dark, circulating water conditions to reach adsorption equilibrium;

[0074] 2) Photocatalytic reaction: under visible light, the catalytic oxidation reaction was carried out for 3 h to obtain 2,5-furandicarboxaldehyde (DFF). As shown in Figure 5 the results, the DFF selectivity of 10% IMo6-25% SZIS was 85%.

[0075] 3) When the loading amount of the Anderson-type heteropoly acid salt IMo6 was appropriately adjusted, as shown in Figure 5 , the DFF selectivity of visible light catalytic oxidation was also much higher than the DFF selectivity of 36% of ZnIn2S4.

[0076] The above specific implementation tests show that the loading of (NH4)3H6CoMo6O 24 , (NH4)4H6CuMo6O 24 , Na3H6FeMo6O 24 , Na5IMo6O 24 , (NH4)4ZnMo6O 24The Anderson type polyoxometalate SnIn4S8-ZnIn2S4 significantly improves the redox capacity of 5-hydroxymethylfurfural (HMF). And, through test tests show that, in the process of photocatalytic oxidation reaction, due to the coupling of Anderson type heteropoly acid and polyoxometalate SnIn4S8-ZnIn2S4, the recombination probability of surface photogenerated electrons and photogenerated holes is low and the charge transfer impedance is small, the electron-hole is effectively separated, which is conducive to the transfer of photogenerated electrons, and can significantly improve the selectivity of photocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to prepare 2,5-furan dicarboxylic acid (DFF). And, the experimental results also show that, under the best reaction condition, the photocatalytic method of the present application can improve the selectivity of DFF to 98%, close to the goal of completely oxidizing HMF to DFF.

[0077] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing DFF by oxidizing HMF based on SnIn4S8-ZnIn2S4 supported on Anderson-type polyoxometalates, characterized in that... The steps are as follows: 1) Preparation of SnIn4S8-ZnIn2S4 supported on Anderson-type polyoxometalates: Step 1.1) Disperse ZnCl2, InCl3·4H2O and C2H5NS in deionized water, stir at room temperature for 20-40 min, then transfer to a reaction vessel and react at 200-220 °C until complete. After cooling, washing, and drying overnight, ZnIn2S4 is obtained. The molar ratio of ZnCl2, InCl3·4H2O and C2H5NS is 1:2:

6. Step 1.2) ZnIn2S4 was ultrasonically dispersed in anhydrous ethanol, SnCl4·5H2O and InCl3·4H2O were added, and the mixture was stirred at room temperature until completely dispersed. Then TAA was added and stirred until completely dissolved. After drying overnight, SnIn4S8-ZnIn2S4 was obtained by in-situ growth. The molar ratio of ZnIn2S4, SnCl4·5H2O, InCl3·4H2O and TAA is 1:0.1~0.5:0.4~2:1.2~6; Step 1.3) Add 5-40% by mass of Anderson-type heteropolyacid salt (SnIn4S8-ZnIn2S4), wherein the Anderson-type heteropolyacid salt is (NH4)3H6CoMo6O 24 (NH4)4H6CuMo6O 24 Na3H6FeMo6O 24 Na5IMo6O 24 Heat any one of the following to 70-80℃ until the reaction is complete, then cool to room temperature, centrifuge to collect the yellow-brown powder, and after washing and drying, obtain SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate. 2) Dark reaction: SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate was added to an aqueous solution of 5-hydroxymethylfurfural (HMF), wherein the mass ratio of SnIn4S8-ZnIn2S4 loaded with Anderson-type polyoxometalate to HMF was 1~5:

1. Then, place it in a photocatalytic reactor at 0~40°C. o C. Under light-proof and circulating water conditions, stir the reaction for 0.2~1h to reach adsorption equilibrium; 3) Photocatalytic reaction: Under light irradiation, after catalytic oxidation for 1-6 h, 2,5-furandicarboxaldehyde (DFF) is obtained.

2. The method according to claim 1, characterized in that... The illumination conditions are any one of ultraviolet light, visible light, and ultraviolet-visible light.

3. The method according to claim 1, characterized in that... The dark reaction time is 0.5 h, and the photocatalytic reaction time is 3 h.

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