Photocatalytic performance composite material, preparation method and application thereof

Abstract

The application discloses a kind of photocatalytic performance composite materials, the composite material is schulte mineral-titanium dioxide supported biochar, the surface of the biochar is loaded with schulte mineral and titanium dioxide, and the schulte mineral is also connected titanium dioxide.The composite material obtained by the application has excellent structural effect, the surface of the biochar with wrinkle structure is uniformly covered with schulte mineral and TiO2, wherein the schulte mineral is also combined with TiO2 closely.The composite material of the application can effectively enhance the electron transfer efficiency of photoelectronic and hole, increase the catalytic efficiency of catalyst.The composite material of the application has the advantages of short processing time and large capacity of processing.The precursor material for material synthesis is derived from waste biomass resources, FeSO4·7H2O is widely available and low in price, and TiO2 nanoparticles is low in price, so the catalyst in the application has the advantages of low cost, easy popularization and easy operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of materials, in particular to a photocatalytic performance composite material and a preparation method and application thereof. BACKGROUND

[0002] With the development of leather, food, textile and other industries and the abuse of drugs, organic matters, especially antibiotics and other persistent organic pollutants, exist widely in water environment. The accumulation of antibiotics in aquatic environment leads to the generation of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs), which threatens public health. Therefore, antibiotics as emerging organic micro-pollutants have attracted great attention of researchers in the environmental field.

[0003] At present, a variety of methods have been developed to treat organic pollutants such as antibiotics, including adsorption, chemical oxidation, electrochemical oxidation, photocatalytic oxidation and biological methods. The adsorption method can only separate the pollutants from wastewater, and cannot degrade the antibiotics into small molecular products; in addition, many adsorption materials are difficult to be recycled. Antibiotics have an inhibitory effect on microbial activity, so the biological method has the disadvantage of low efficiency. Chemical oxidation, electrochemical oxidation and photocatalytic oxidation methods are non-destructive methods, which are difficult to degrade organic matter into small molecules with low toxicity. Therefore, it has become an important problem to develop a sustainable and feasible method for removing antibiotics. SUMMARY

[0004] Some researchers in the prior art have prepared titanium dioxide / zeolite composite catalysts to treat dye wastewater. Although titanium dioxide can improve the catalytic activity of zeolite, the phenomenon of agglomeration still occurs during the preparation of titanium dioxide and zeolite, so that the improvement of catalytic efficiency in the wastewater treatment process is not significant. In addition, since the environment of the catalyst is in wastewater, the difference in acidity and alkalinity in different wastewater environments is large, which is a challenge to the structural stability of the catalyst. How to form a stable structure is the premise of exerting the catalytic effect.

[0005] The present application discloses a photocatalytic performance composite material, which has excellent photo-generated electron, hole and semiconductor performance, short treatment time, large treatment capacity, strong regenerability and no secondary pollution.

[0006] The present application is realized by the following technical solutions:

[0007] The photocatalytic performance composite material provided by the present application is a zeolite-titanium dioxide loaded biochar (zeolite / titanium dioxide@biochar), the surface of the biochar is loaded with zeolite and titanium dioxide, and the zeolite is also connected to the titanium dioxide.

[0008] The above design of the present application has the following advantages: the schottky mineral has high active hydroxyl groups, thus having high catalytic activity; the connection between the titanium dioxide and the schottky mineral and the semiconductor performance of the titanium dioxide can promote the schottky mineral to generate more hydroxyl radicals under light, thus improving the catalytic activity of the schottky mineral; on this basis, the present application further designs the biochar, and the schottky mineral and the titanium dioxide are loaded on the surface of the biochar, which can promote the uniform dispersion of the schottky mineral and the titanium dioxide, thus improving the cooperation efficiency between the schottky mineral and the titanium dioxide and increasing the specific surface area of the composite material, thus improving the catalytic efficiency.

[0009] As a further scheme, the source of the biochar of the composite material includes one or more of distiller's grains, rice, straw, sawdust and discarded vegetables.

[0010] As a further scheme, the source of the biochar includes distiller's grains. The distiller's grains are rich in aliphatic hydrocarbons, and in the preparation process of the biochar, the aliphatic hydrocarbons in the distiller's grains are condensed into aromatic hydrocarbons, and the whole preparation process is a process of increasing aromaticity and decreasing polarity, which is more conducive to generating a rougher wrinkle structure, so that the titanium dioxide and the schottky mineral are more uniformly dispersed and loaded on the surface of the biochar, thus increasing the specific surface area of the catalyst and forming a stable structure of the biochar loaded with the titanium dioxide and the schottky mineral. This is conducive to the stable catalytic effect in the wastewater environment, thus improving the catalytic activity and catalytic efficiency of the composite material.

[0011] The present application also provides a preparation method of the composite material, which comprises mixing the distiller's grains with ferrous sulfate hydrate (FeSO4·7H2O), then adding H2O2, loading the schottky mineral on the surface of the distiller's grains, then adding TiO2 nanoparticles for mixing, and performing first heating treatment at 30-100 DEG C to preliminarily form the schottky mineral-titanium dioxide loaded biochar, and performing second heating treatment at 300-1000 DEG C to obtain the target catalyst. In the preparation process of the present application, in order to promote the distiller's grains to form a stable structure with the schottky mineral and the titanium dioxide in the process of generating the biochar, the present application adopts a two-step heating method, which is conducive to the preliminary connection and dispersion between the substances in the first heating process, and prepares for the stable structure in the second heating process. In the second heating process, the aromaticity of the distiller's grains is increased and the polarity is decreased, a rough wrinkle structure is formed, and the dispersion of the schottky mineral and the titanium dioxide is promoted, and then the schottky mineral and the titanium dioxide are stably loaded on the surface of the biochar. Finally, the surface of the biochar is loaded with the schottky mineral and the titanium dioxide, and the schottky mineral connects the stable structure of the titanium dioxide.

[0012] As a further scheme, the preparation method of the vinasse comprises drying the vinasse at 30-80 DEG C, and then crushing the dried vinasse to obtain a powder with a particle size of 40-150 microns.

[0013] As a further scheme, the addition amount of the ferrous sulfate hydrate is 5-10 g / 100 mL; the addition amount of the vinasse is 1-40 g / 100 mL; the addition amount of the H2O2 (30% H2O2 by mass) is 1-4 mL / 100 mL; and the addition amount of the TiO2 nanoparticles is 0.1-0.5 g / 100 mL.

[0014] As a further scheme, the first heating treatment is ended when the moisture in the mixed substance is dried; and the second heating treatment is performed in an atmospheric atmosphere for 1-4 hours.

[0015] The application further provides an application of the composite material in waste liquid.

[0016] As a further scheme, the waste liquid comprises azo dyes or antibiotics.

[0017] As a further scheme, the application method comprises adding the composite material into the waste liquid, and centrifuging.

[0018] As a further scheme, the temperature of the waste liquid is 20-40 DEG C, and the pH of the waste liquid is 3-11; the centrifugation speed is 150-200 rpm, and the centrifugation time is 10-120 minutes.

[0019] The application has the following characteristics and advantages:

[0020] (1) The composite material obtained by the application has excellent structural effect, the surface of the biochar with wrinkle structure is uniformly covered with the scherrerite and the TiO2, and the scherrerite is also closely combined with the TiO2.

[0021] (2) The composite material of the application can effectively enhance the electron transfer efficiency of photoelectrons and holes, and increase the catalytic efficiency of the catalyst.

[0022] (3) The scherrerite and the TiO2 in the composite material of the application are uniformly dispersed on the surface of the biochar, and the three form a stable connection structure, which can play a stable catalytic role in the waste liquid.

[0023] (4) The precursor material for synthesizing the material is derived from waste biomass resources, FeSO4.7H2O is widely available and low in price, and TiO2 nanoparticles are low in price, so the catalyst in the application has the advantages of low cost, easy popularization and easy operation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a Fourier transform infrared spectrum for exploring the surface light energy group of biomass, biochar and composite material.

[0025] Figure 2 It is an SEM graph of the composite material before and after the second heating treatment, wherein a represents the SEM graph of the catalyst before the second heating treatment, and b represents the SEM graph of the catalyst after the second heating treatment.

[0026] Figure 3 It is a degradation curve of sulfonamide dimethylpyrimidine in an organic pollutant system treated by the composite material with different adding amounts.

[0027] Figure 4 It is a degradation curve of rhodamine B (RhB) in an organic pollutant system treated by the composite material with different adding amounts.

[0028] Figure 5 It is a degradation curve of sulfonamide dimethylpyrimidine in a sulfonamide dimethylpyrimidine system treated by the composite material under pH conditions.

[0029] Figure 6 It is a continuous degradation curve of sulfonamide dimethylpyrimidine in a sulfonamide dimethylpyrimidine system treated by the composite material.

[0030] Figure 7 It is a continuous degradation curve of sulfonamide dimethylpyrimidine in a sulfonamide dimethylpyrimidine system treated by the composite material after repeated heat treatment. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the light catalytic performance composite material, the preparation method of the light catalytic performance composite material will be described more comprehensively below, and the embodiments of the application are given, but the scope of the application is not limited thereto.

[0032] Example 1: The preparation method of the photocatalytic performance composite material in the present application includes: collecting discarded waste distiller's grains from liquor production enterprises after solid state fermentation, drying the distiller's grains at 30-80°C, then crushing and sieving the dried distiller's grains to obtain distiller's grain powder of 40-150 μm. Mix the distiller's grain powder into ferrous sulfate hydrate, then add H2O2, load the schiillerite on the surface of the distiller's grains, then add TiO2 nanoparticles for mixing, heat at 30-100°C for the first time to preliminarily form schiillerite-titanium dioxide loaded biochar, and heat at 300-1000°C for the second time to obtain the target catalyst.

[0033] The addition amount of the ferrous sulfate hydrate is 5-10 g / 100 mL; the addition amount of the distiller's grains is 1-40 g / 100 mL; the addition amount of H2O2 (30%) is 1-4 mL / 100 mL; and the addition amount of TiO2 nanoparticles is 0.1-0.5 g / 100 mL. The first heating treatment ends when the water in the mixed substances is dried; and the second heating treatment is performed in an atmospheric atmosphere for 1-4 h.

[0034] Example 2: We use the composite catalyst obtained in the present application to degrade sulfamethazine, and the method process includes: respectively weighing the distiller's grain powder, ferrous sulfate, TiO2 nanoparticles, and the composite catalyst of the present application, and adding them into 100 mL of a sulfamethazine (SMT) solution with a concentration of 0.4 mg / L, and performing the reaction under the conditions of 50w LED lamp irradiation, waste liquid temperature of 30°C, and 200 rpm, and sampling and detecting the content change of sulfamethazine at different time points.

[0035] Example 3: We use the composite catalyst obtained in the present application to degrade rhodamine B, and the method process includes: respectively weighing the distiller's grain powder, TiO2 nanoparticles, TiO2-biochar material, and the composite catalyst of the present application, and adding them into 100 mL of a rhodamine B solution with a concentration of 5 mg / L, and performing the reaction under the conditions of 50w LED lamp irradiation, waste liquid temperature of 30°C, and 200 rpm. Sampling and detecting the content change of sulfamethazine at different time points.

[0036] Example 4: We used the composite catalyst obtained by the present invention to degrade sulfamethazine. The method included weighing 0.1g of the composite catalyst of the present invention and adding it to 100mL of a 0.4mg / L sulfamethazine (SMT) solution. The pH values ​​of the sulfamethazine solution were adjusted to 3, 5, 7, 9 and 11 using hydrochloric acid and sodium hydroxide, respectively. The reaction was carried out under the conditions of 50W LED lamp irradiation, 30℃ and 200rpm.

[0037] Example 5: We used the composite catalyst obtained by this invention to degrade sulfamethazine. The method included weighing 0.1 g of the composite catalyst of this invention and adding it to 100 mL of a 0.4 mg / L sulfamethazine (SMT) solution. 0.04 mg of sulfamethazine was added at 40 min, 80 min, 120 min, 160 min, 200 min, 240 min, and 280 min, respectively, and the sustained degradation ability was observed. The reaction was carried out under 50 W LED irradiation, 30 °C, and 200 rpm.

[0038] Example 6: 100 mL of a 0.4 mg / L sulfamethazine (SMT) solution was prepared. The composite material from Example 5 was recovered, retreated at 500°C under atmospheric conditions for 2 h, and then added to the sulfamethazine solution. 0.04 mg of sulfamethazine was added at 40 min, 80 min, 120 min, 160 min, 200 min, 240 min, and 280 min, respectively, to observe the sustained degradation ability. The reaction was carried out under 50 W LED irradiation at 30°C and 200 rpm.

[0039] Validation Result Analysis

[0040] We obtained a photocatalytically active composite material, Schiele mineral-titanium dioxide supported biochar, using the preparation method of this invention.

[0041] The bonding mechanism between Schiele minerals and titanium dioxide on the surface of biochar is as follows: Figure 1 As shown, compared to pure biochar, the composite material has significantly fewer functional groups such as -OH, CH, C=O, and CO on its surface. Therefore, the Schist minerals and titanium dioxide may be tightly bonded to the biochar through the -OH, CH, C=O, and CO functional groups on the biochar surface, and thus shield these functional groups.

[0042] Microstructure of composite materials, such as Figure 2 As shown. Among them. Figure 2 'a' represents the SEM image of the mixed material before the second heat treatment.Figure 2 b represents the SEM image of the composite material after the second heat treatment. We can clearly see from the image that in the composite material obtained by this invention, biochar forms a rough, wrinkled structure, ferrous sulfate forms Schiele minerals, and Schiele minerals and titanium dioxide are loaded onto the surface of the biochar.

[0043] We obtained a composite material for the degradation of sulfadimethylpyrimidine and investigated the degradation effects of distiller's grains powder, ferrous sulfide, TiO2 nanoparticles, and the composite material of this invention on sulfadimethylpyrimidine. Figure 3 As shown. We start from Figure 3 As can be seen, the degradation ability of the composite material of the present invention is better than that of distiller's grains powder, ferrous sulfide, and TiO2 nanoparticles. Furthermore, the degradation effect on sulfadiazine is more significant with the increase of the amount of composite material added. The best effect is achieved when the amount of composite material added is 0.1 g / 100 mL, and the degradation rate of SMT reaches about 80% at 40 min.

[0044] We obtained a composite material for degrading Rhodamine B and investigated the degradation effects of distiller's grains powder, TiO2 nanoparticles, TiO2-biochar materials, and the composite material of this invention on Rhodamine B. Figure 4 As shown. We start from Figure 4 As can be seen, the degradation ability of the composite material of the present invention is superior to that of distiller's grains powder, TiO2 nanoparticles, and TiO2-biochar material. Furthermore, the degradation efficiency of Rhodamine increases significantly with the increase of the amount of composite material added. At 0.1 g / 100 mL, the composite material can degrade approximately 90% of Rhodamine B in 5 minutes, and the degradation rate of Rhodamine B reaches approximately 100% in 20 minutes. This example demonstrates that the composite material of the present invention has excellent catalytic efficiency.

[0045] We further investigated the degradation ability of the composite material of the present invention for sulfadimethylpyrimidine in different pH environments, such as... Figure 5 As shown, the composite materials of this invention can catalyze the degradation of sulfadiazine within an environmental pH range of 3-11. Specifically, within an environmental pH range of 3-9, the composite materials of this invention can degrade at least 60% of sulfadiazine, and especially at pH 3, the degradation rate of sulfadiazine reaches 100%. This embodiment demonstrates that the composite materials of this invention are applicable to wastewater in different pH environments, and are particularly suitable for acidic wastewater environments.

[0046] We also investigated the sustained degradation ability of the composite material of the present invention for sulfadimethylpyrimidine, such as Figure 5 As shown. We can see from Figure 6As can be seen, the composite material exhibited good antibiotic degradation activity until 280 minutes later, but the catalytic efficiency decreased slightly with prolonged catalytic time, catalyzing a total of 0.28 mg of SMT within 280 minutes. This example demonstrates the sustained degradation capability of the composite material of the present invention.

[0047] We separated the composite material from Example 6, subjected it to a second heat treatment, and then studied the sustained degradation ability of the composite material after the second heat treatment on sulfadimethylpyrimidine. Figure 7 As shown. We can see from Figure 7 As can be seen, the material exhibits good antibiotic degradation activity until 160 minutes later, but the catalytic efficiency decreases to some extent with prolonged catalytic time, catalyzing a total of 0.26 mg of SMT within 280 minutes. This invention demonstrates that the material has good reusability.

[0048] In summary, the photocatalytic composite material of the present invention has excellent photogenerated electron and hole properties and semiconductor properties; and has the advantages of short processing time, large processing capacity, strong regeneration ability, and no secondary pollution.

[0049] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a photocatalytic composite material, characterized in that, The composite material is Schiele mineral-titanium dioxide supported biochar, wherein the surface of the biochar is loaded with Schiele mineral and titanium dioxide, and the Schiele mineral is also connected to titanium dioxide. The method includes mixing hydrated ferrous sulfate FeSO4·7H2O into the lees, then adding H2O2 to load Scherstein minerals onto the surface of the lees; then adding TiO2 nanoparticles for mixing, and performing a first heat treatment at 30℃-100℃ to initially form Scherstein mineral-titanium dioxide supported biochar; and performing a second heat treatment at 300℃-1000℃ to obtain the target composite material.

2. The preparation method according to claim 1, characterized in that, The method for preparing the lees includes drying the lees at 30℃-80℃ and then pulverizing them to obtain powder of 40μm-150μm.

3. The application of the composite material obtained by the preparation method according to any one of claims 1-2 in the treatment of waste liquid including azo dyes or antibiotics.

4. The application according to claim 3, characterized in that, The method of application includes adding the composite material to waste liquid and centrifuging.

5. The application according to claim 4, characterized in that, The temperature of the waste liquid is 20℃-40℃, and the pH of the waste liquid is 3-11; the centrifugation speed is 150rpm-200rpm, and the centrifugation time is 10min-120min.

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