CoOxT-perylene diimide composite photocatalyst with size effect as well as preparation method and application of CoOxT-perylene diimide composite photocatalyst

Abstract

The invention discloses a CoOxT-perylene diimide composite photocatalyst with a size effect and a preparation method and application thereof.The preparation method comprises the steps that biuret, perylene 3, 4, 9, 10 tetracarboxylic dianhydride, anhydrous zinc acetate and imidazole are subjected to a first reaction, and a perylene diimide photocatalyst is prepared; and dispersing the perylene diimide photocatalyst in water, then adding a cobalt source, carrying out a second reaction, then carrying out rotary evaporation, and annealing at 250-400 DEG C in argon. By changing the annealing temperature, the size of the CoOx nano particles can be regulated and controlled, and the CoOx nano particles have good photocatalytic water decomposition and oxygen evolution performance. More importantly, the CoOx nanoparticles have a size effect on photocatalytic water decomposition oxygen evolution, that is, the CoOxT at perylene diimide shows regularly-changed oxygen evolution performance along with the change of the size of the CoOx nanoparticles. The method is mild in operation, easy to control, good in reproducibility and high in material yield.

Description

Technical Field

[0001] This invention relates to the field of photocatalytic water splitting, specifically to a CoO4 with size effect. x T@perylene diimide composite photocatalyst, preparation method and application. Background Technology

[0002] In the 21st century, humanity faces two major challenges: energy and the environment. To achieve sustainable development, the development of clean and renewable energy sources is essential. Photocatalytic water splitting for hydrogen and oxygen production is a promising method for achieving stable solar energy conversion. Current research mainly focuses on the half-reaction of photocatalytic water splitting for hydrogen production, but the four-electron reaction process and high redox potential make the oxygen evolution reaction in photocatalytic water splitting the rate-limiting step in the overall water splitting process. Therefore, developing oxygen evolution catalysts with effective photoresponse and deep valence band positions to optimize the four-electron reaction process and meet the thermodynamic requirements of water oxidation is crucial for achieving efficient photocatalytic water splitting for oxygen evolution. However, this field still faces significant challenges.

[0003] Perylene diimide is a highly crystalline and stable linear conjugated polymer with excellent light absorption and tunable optical and electronic properties. Most importantly, perylene diimide typically possesses a deep valence band position, and its high crystallinity and strong molecular dipoles facilitate the formation of a strong built-in electric field, promoting the separation and transport of photogenerated carriers, thus it has been reported as an excellent oxygen evolution photocatalyst. However, its surface catalytic reaction rate is relatively low, so it is necessary to improve its catalytic reaction rate. Summary of the Invention

[0004] To overcome the problem of low catalytic reaction rates caused by catalysts in existing technologies, the present invention aims to provide a CoO with size effect. x T@Perylene diimide composite photocatalyst, preparation method, and application: This perylene diimide exhibits excellent photocatalytic oxygen evolution performance. CoO is loaded onto the perylene diimide. x Performance optimization of co-catalysts was achieved by changing the annealing temperature of CoO. x By rationally controlling the size of the catalyst, the catalytic reaction rate can be improved, and different sizes of CoO can be used to... x The co-catalyst can improve oxygen evolution performance to varying degrees.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A CoO with size effect x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: Biuret, perylene 3,4,9,10 The perylene diimide photocatalyst was prepared by reacting tetracarboxylic acid dianhydride, anhydrous zinc acetate, and imidazole in the first reaction. Perylene diimide photocatalyst was dispersed in water, then a cobalt source was added, followed by a second reaction and rotary evaporation. Annealing was then performed under argon atmosphere at 250-400 °C to obtain CoO exhibiting size effect. x T@perylene diimide composite photocatalyst.

[0006] Furthermore, the mass ratio of biuret, perylene-3,4,9,10-tetracarboxylic dianhydride, anhydrous zinc acetate, and imidazole is 0.21 g : 0.78 g : 0.27-0.57 g : 5-10 g.

[0007] Furthermore, the first reaction temperature is 140-180 ℃, and the first reaction time is 5 h.

[0008] Furthermore, the molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5-3 mol: 0.02 mol.

[0009] Furthermore, the cobalt source is cobalt chloride or cobalt nitrate.

[0010] Furthermore, the amount of cobalt source added is 1.0 wt.% of the mass of perylene diimide photocatalyst based on the atomic mass of Co.

[0011] Furthermore, the second reaction time is 12-24 h, and the second reaction temperature is 60-90 ℃.

[0012] Furthermore, the rotary evaporation temperature is 50-70 ℃; the annealing time is 2-5 h.

[0013] A CoO with size effect x T@perylene diimide composite photocatalyst.

[0014] A CoO with size effect x Application of T@perylene diimide composite photocatalyst in photocatalytic water splitting and oxygen evolution.

[0015] Compared with the prior art, the present invention has the following advantages: This invention uses biuret and perylene. 3,4,9,10 A perylene diimide photocatalyst was prepared using tetracarboxylic dianhydride, anhydrous zinc acetate, and imidazole as raw materials. Then, a cobalt source was introduced, followed by annealing to obtain CoO₂ exhibiting size effects. x T@Perylene diimide composite photocatalyst, this invention rationally controls the CoO cocatalyst by changing the annealing temperature. x The particle size of the nanoparticles shifts the center of their d-band upwards, thereby enhancing the CoO₂ content. xThe adsorption strength of nanoparticles for photocatalytic oxygen evolution intermediates (OH*, O*, OOH*) enhances the kinetic driving force of the photocatalytic oxygen evolution reaction and promotes surface reactions. Therefore, the composite catalyst prepared in this invention exhibits excellent photocatalytic oxygen evolution performance. The preparation method of this invention is simple, with mild preparation conditions, easily scalable, low-cost, and readily available for mass production. Furthermore, it is pollution-free, practical, highly operable, energy-saving, and environmentally friendly.

[0016] The CoO prepared by this invention x The T@perylene diimide composite photocatalyst exhibits excellent photocatalytic oxygen evolution performance. The perylene diimide oxygen evolution rate is 100.94 μmol / h. -1 It has the optimal CoO x CoO size x The oxygen evolution rate of the T@perylene diimide composite photocatalyst is 421.93 μmol / h. -1 . Attached Figure Description

[0017] Figure 1 This is a scanning electron microscope (SEM) image of the perylene diimide photocatalyst prepared in Example 1 of the present invention; Figure 2 Transmission electron microscopy (TEM) images of the perylene diimide photocatalysts prepared in Examples 1-4 of this invention and CoO synthesized at different annealing temperatures. x TEM images of the T@perylene diimide composite photocatalyst; where a is a transmission electron microscope (TEM) image of the perylene diimide photocatalyst prepared in Example 1 of this invention, and b is a CoO synthesized at annealing temperature of 250 °C in Example 1. x TEM image of T@perylene diimide composite photocatalyst, c is CoO synthesized at annealing temperature of 300 °C in Example 2. x TEM image of T@perylene diimide composite photocatalyst, d is CoO synthesized at annealing temperature of 350 °C in Example 3. x TEM image of T@perylene diimide composite photocatalyst, e is CoO synthesized at annealing temperature of 400 °C in Example 4. x TEM image of T@perylene diimide composite photocatalyst; Figure 3 The X-ray diffraction (XRD) pattern of the perylene diimide photocatalyst prepared in Example 1 of this invention; Figure 4 The perylene diimide photocatalysts and CoO prepared in Examples 1-4 of this invention x Photocatalytic oxygen evolution performance of T@perylene diimide composite photocatalyst (from left to right, the annealing temperature gradually increases, in the order of Example 1, Example 2, Example 3 and Example 4). Detailed Implementation

[0018] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0019] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0020] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0021] A CoO with size effect according to the present invention x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: mixing biuret, perylene... 3,4,9,10 An organic synthesis reaction was carried out using tetracarboxylic acid dianhydride, anhydrous zinc acetate, and imidazole to obtain the product. Hydrochloric acid was added to the product, followed by filtration, washing until neutralized, and drying to obtain a perylene diimide photocatalyst. The perylene diimide was ultrasonically dispersed in ultrapure water, and then a cobalt source was added for reaction. After rotary evaporation and annealing under argon, CoO exhibiting size effect was obtained. x T@perylene diimide composite photocatalyst.

[0022] The preparation method of the photocatalyst specifically includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.27-0.57 g: 5-10 g and react at a temperature of 140-180 ℃ for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5-3 mol: 0.02 mol. (3) The stirred product obtained in step (2) is filtered, then washed with water until neutral, and dried in a vacuum oven at 50-70°C to obtain perylene diimide; (4) Disperse perylene diimide in ultrapure water by ultrasonication, and then add a cobalt source (cobalt chloride or cobalt nitrate) to react. The amount of cobalt source added is calculated as 1-3 wt.% of the atomic mass of Co in the perylene diimide. The reaction time is 12-24 h and the reaction temperature is 60-90 ℃. (5) The product obtained in step (4) is subjected to rotary evaporation at 50-70 °C and annealed at 250-400 °C under argon for 2-5 h to obtain CoO with size effect. x T@perylene diimide composite photocatalyst, i.e., CoO x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0023] In this invention, a co-catalyst CoO is supported on perylene diimide. x When using nanoparticles, the annealing temperature is changed to adjust the oxidation temperature of CoO. x A series of CoO2 were prepared by reasonably controlling the size. x The T@perylene diimide composite photocatalyst exhibits regular photocatalytic oxygen evolution performance.

[0024] The following are specific examples.

[0025] Example 1 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.27 g: 5 g and react at 140 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 50 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 12 h and the reaction temperature was 60 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 50 °C and annealed at 250 °C for 2 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0026] Example 2 The difference from Example 1 is that the annealing temperature is 300 °C, but everything else is the same as in Example 1.

[0027] Example 3 The difference from Example 1 is that the annealing temperature is 350 °C, but everything else is the same as in Example 1.

[0028] Example 4 The difference from Example 1 is that the annealing temperature is 400 °C, but everything else is the same as in Example 1.

[0029] Figure 1 Here is a scanning electron microscope (SEM) image of the perylene diimide photocatalyst prepared in Example 1; from Figure 1 It can be seen that perylene diimide is in a blocky form.

[0030] Figure 2 Image a is a transmission electron microscope (TEM) image of the perylene diimide photocatalyst prepared in Example 1. As can be seen from the image, perylene diimide has high crystallinity, and the interplanar spacing of 0.872 nm corresponds to the (002) crystal plane of perylene diimide. Figure 2 The term "be" refers to CoO synthesized at different annealing temperatures in Examples 1-4. x TEM image of T@perylene diimide composite photocatalyst (by...) Figure 2 From B to Figure 2 (As the annealing temperature gradually increases,) the figure shows that dispersed CoO was successfully loaded onto the perylene diimide. x Nanoparticles, and CoO loaded on perylene diimide at different annealing temperatures. x Nanoparticles vary in size.

[0031] Figure 3 The X-ray diffraction (XRD) pattern of the perylene diimide photocatalyst prepared in Example 1; from Figure 3 It can be seen from this that perylene diimide has good crystallinity.

[0032] Photocatalytic oxygen evolution test: 20 mg of photocatalyst powder and 100 mg of lanthanum oxide were added to the reactor, and then 100 mL of 20 mmol / L silver nitrate aqueous solution was added as a sacrificial agent. The photocatalytic water splitting and oxygen evolution reaction was carried out under visible light conditions.

[0033] Figure 4 Perylene diimide photocatalysts and CoO prepared in Examples 1-4 x Photocatalytic oxygen evolution performance of T@perylene diimide composite photocatalyst (from left to right, annealing temperature gradually increases); From Figure 4 As can be seen, the oxygen evolution rate of perylene diimide is 100.94 μmol / h. -1 It has the optimal CoO x CoO size xThe T@perylene diimide composite photocatalyst exhibited regularly varying photocatalytic oxygen evolution performance in water splitting, with an oxygen evolution rate of 421.93 μmol / h. -1 With CoO x The oxygen evolution performance of composite photocatalysts changes with the size of nanoparticles, reflecting the effect of CoO2. x Size effect of nanoparticles on photocatalytic water splitting and oxygen evolution.

[0034] Example 5 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.37 g: 7 g and react at 150 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.6 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 55 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 15 h and the reaction temperature was 65 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 55 °C and annealed at 350 °C for 3 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0035] Example 6 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.47 g: 8 g and react at 160 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.7 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 60 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 18 h and the reaction temperature was 70 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 60 °C and annealed at 300 °C for 4 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0036] Example 7 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.57 g: 9 g and react at 170 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.8 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 65 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 21 h and the reaction temperature was 75 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 65 °C and annealed at 280 °C for 4.5 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0037] Example 8 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.57 g: 10 g and react at 180 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.9 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 24 h and the reaction temperature was 80 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 250 °C for 5 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0038] Example 9 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.57 g: 10 g and react at 180 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 3 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt nitrate was added to carry out the reaction. The amount of cobalt source added was calculated as 1.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 24 h and the reaction temperature was 85 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 400 °C for 5 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0039] Example 10 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.27 g: 8 g and react at 180 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 3 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt chloride was added to carry out the reaction. The amount of cobalt source added was calculated as 2.5 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 24 h and the reaction temperature was 90 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 400 °C for 5 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0040] Example 11 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.37 g: 5 g and react at 180 ℃ for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 3 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt nitrate was added to carry out the reaction. The amount of cobalt source added was calculated as 1.5 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 24 h and the reaction temperature was 70 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 350 °C for 5 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0041] Example 12 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.37 g: 5 g and react at 180 ℃ for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt nitrate was added to carry out the reaction. The amount of cobalt source added was calculated as 3.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 24 h and the reaction temperature was 70 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 300 °C for 3 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0042] Example 13 This embodiment provides a CoO with size effect. x The preparation method of T@perylene diimide composite photocatalyst includes the following steps: (1) Add biuret, perylene-3,4,9,10-tetracarboxylic acid dianhydride, anhydrous zinc acetate and imidazole to a flask in a mass ratio of 0.21 g: 0.78 g: 0.37 g: 5 g and react at 140 °C for 5 h. (2) Add hydrochloric acid to the product obtained in step (1) and stir to obtain a stirred product. The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5 mol: 0.02 mol. (3) The stirred product obtained in step (2) was filtered, then washed with water until neutral, and dried in a vacuum oven at 70 °C to obtain perylene diimide photocatalyst; (4) Perylene diimide was ultrasonically dispersed in ultrapure water, and then cobalt nitrate was added to carry out the reaction. The amount of cobalt source added was calculated as 2.0 wt.% of the atomic mass of Co to the mass of perylene diimide; the reaction time was 18 h and the reaction temperature was 75 ℃. (5) The product obtained in step (4) was subjected to rotary evaporation at 70 °C and annealed at 300 °C for 3 h under argon atmosphere to obtain CoO. x T@perylene diimide (T represents different annealing temperatures) composite photocatalyst.

[0043] Comparative Example 1 Unlike Example 1, the annealing temperature was 200 °C, and CoO was prepared. x 200@perylene diimide, other parameters are the same as in Example 1.

[0044] Comparative Example 2 Unlike Example 1, the annealing temperature was 450 °C, and CoO was prepared. x 450@perylene diimide, other parameters are the same as in Example 1.

[0045] Tests showed that the CoO prepared in Comparative Example 1... x The photocatalytic oxygen evolution rate of 200@perylene diimide was 30.72 μmol / h. -1 CoO prepared in Comparative Example 2 x The photocatalytic oxygen evolution rate of 450@perylene diimide is 19.87 μmol / h. -1 The annealing temperature is lower than the photocatalytic oxygen evolution rate in the embodiments of the present invention, which shows that the annealing temperature has a significant impact on the performance of the composite photocatalyst.

[0046] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A CoO with size effect x The preparation method of T@perylene diimide composite photocatalyst is characterized by, Includes the following steps: Biuret, perylene 3,4,9,10 The perylene diimide photocatalyst was prepared by reacting tetracarboxylic acid dianhydride, anhydrous zinc acetate, and imidazole in the first reaction. Perylene diimide photocatalyst was dispersed in water, then a cobalt source was added, followed by a second reaction and rotary evaporation. Annealing was then performed under argon atmosphere at 250-400 °C to obtain CoO exhibiting size effect. x T@perylene diimide composite photocatalyst.

2. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The mass ratio of biuret, perylene-3,4,9,10-tetracarboxylic dianhydride, anhydrous zinc acetate, and imidazole is 0.21 g:0.78 g:0.27-0.57 g:5-10 g.

3. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The first reaction temperature is 140-180 ℃, and the first reaction time is 5 h.

4. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The molar ratio of hydrochloric acid to perylene-3,4,9,10-tetracarboxylic acid dianhydride is 2.5-3 mol: 0.02 mol.

5. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The cobalt source is cobalt chloride or cobalt nitrate.

6. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The amount of cobalt source added is 1.0 wt.% of the mass of perylene diimide photocatalyst based on the atomic mass of Co.

7. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The second reaction time is 12-24 h, and the second reaction temperature is 60-90 ℃.

8. The CoO with size effect according to claim 1 x The preparation method of T@perylene diimide composite photocatalyst is characterized by, The rotary evaporation temperature is 50-70 ℃; the annealing time is 2-5 h.

9. A CoO₂ exhibiting size effect prepared by the method according to any one of claims 1-8 x T@perylene diimide composite photocatalyst.

10. A size-effect CoO2 prepared by the method according to any one of claims 1-8 x Application of T@perylene diimide composite photocatalyst in photocatalytic water splitting and oxygen evolution.

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