CN115888760A - Photocatalytic nanomaterial-microorganism heterozygote and preparation method and application thereof - Google Patents

Abstract

The invention discloses a photocatalytic nano-material-microbial hybrid and its preparation method and application. The preparation method comprises the following steps: adding graphene oxide to water-soluble divalent cadmium salt, thiourea and polyvinylpyrrolidone In the mixed solution, carry out hydrothermal reaction, then wash and vacuum dry to obtain CdX/RGO material; cultivate Shewanella under aerobic conditions to obtain bacterial liquid; disperse CdS/RGO material in anaerobic buffer solution to obtain Buffer A: centrifuge the Shewanella bacterium and discard the supernatant, then disperse the precipitate cells obtained by centrifugation into buffer A, mix and stir to obtain CdS/RGO/MR‑1 material. The invention prepares a novel hybrid of photocatalysis-bio-cooperative efficient hydrogen production, which can realize efficient transfer of photogenerated electrons from extracellular to intracellular hydrogenase, so as to promote light energy utilization efficiency and hydrogen production efficiency.

Description

Photocatalytic nanomaterial-microbe hybrid and its preparation method and application

technical field

The invention belongs to the technical field of green hydrogen energy production, and specifically relates to a photocatalyst, a hybrid of a conductive carbon material and a microorganism, a preparation method thereof, and an application for hydrogen production.

Background technique

Solar hydrogen production is a clean energy production technology with great development potential. This technology usually uses photocatalyst to split water to produce hydrogen. The hydrogen production efficiency is generally not high. In addition, the use of microorganisms to anaerobically decompose organic matter can also produce hydrogen. This technology can be coupled with wastewater treatment processes, thus providing a new way for wastewater recycling. However, due to the existence of other competing organic catabolic pathways, the electron donors that can be effectively used for hydrogen production are insufficient, which also limits their hydrogen production efficiency and long-term operational stability.

In recent years, researchers have attempted to construct inorganic-biological hybrid systems (IBSs) to realize the coupling of photocatalytic and biological hydrogen production processes. This system can use the excellent light absorption properties of inorganic semiconductor materials to provide additional electrons for microbial metabolism, and at the same time use the hydrogenase in microbial cells to catalyze the conversion of organic matter to produce hydrogen, so it is expected to achieve a continuous, stable, and low-cost hydrogen production process. However, since the photocatalytic material is located outside the cell and the microbial hydrogenase is located inside the cell, it is difficult for the photogenerated electrons to be effectively utilized by microorganisms, which severely limits the hydrogen production efficiency of IBSs. The key to breaking through this bottleneck is to increase the electron transfer rate at the interface between materials and microbial cells. At present, researchers Lower, B.H. et al. (APPLIED ANDENVIRONMENTAL MICROBIOLOGY, 2009.75(9): p.2931-2935) try to use soluble electronic media such as dye molecules to construct electronic channels between photocatalysts and intracellular hydrogenases. The diffusion and mass transfer efficiency of similar substances is low and will continue to be lost, and some electronic mediator molecules are also cytotoxic, which is not conducive to long-term efficient and stable operation. Therefore, there is an urgent need to develop inorganic-biological hybrids with stronger interfacial electron transfer capabilities to improve their solar-to-hydrogen conversion efficiency.

Contents of the invention

Aiming at the above deficiencies in the prior art, the present invention provides a photocatalyst, a hybrid of conductive carbon materials and microorganisms and its preparation method and hydrogen production application, which solves the problem of the current photocatalytic composite system constructed by inorganic materials and microbial cells. The problem of low interfacial electron transfer efficiency, the present invention uses microorganisms (such as Shewanella) with excellent transmembrane electron transfer capabilities and hydrogen production capabilities, through inorganic photocatalytic materials (such as cadmium sulfide, CdS) and microbial cells Adding two-dimensional nanomaterials (such as graphene oxide) with better biocompatibility and conductivity as the electron transfer medium, imposing the combination of inorganic materials and biological cells and improving the interface electron transfer efficiency, so as to realize the transfer of photogenerated electrons from the outside to the cell. Efficient delivery of internal hydrogenase to promote light energy utilization efficiency and hydrogen production efficiency.

Technical scheme of the present invention is:

The invention relates to a method for preparing a photocatalytic nanomaterial-microbial hybrid, comprising the following steps:

(1) Preparation of CdS/RGO

Adding graphene oxide (GO) into a mixed solution containing water-soluble divalent cadmium salt, thiourea and polyvinylpyrrolidone, performing a hydrothermal reaction, then washing and vacuum drying, to obtain a CdX/RGO material;

(2) Culture of Shewanella

Cultivate Shewanella under aerobic conditions to obtain a bacterial liquid;

(3) Preparation of CdS/RGO/MR-1

Disperse the CdS/RGO material in the anaerobic buffer solution to obtain buffer solution A; centrifuge the supernatant of the bacterial liquid obtained in step (2), and then disperse the precipitate cells obtained by centrifugation into buffer solution A, mix and stir to obtain CdS /RGO/MR-1 material.

Preferably, the water-soluble divalent cadmium salt is cadmium chloride.

Preferably, the concentration of divalent cadmium salt is 90-100mmol/L, the concentration of thiourea is 90-100mmol/L, and the concentration of polyvinylpyrrolidone is 10-12mg/mL;

In step (1), graphene oxide is added with the form of ethylene glycol solution of graphene oxide, and the concentration of the ethylene glycol solution of graphene oxide is 0.4-0.6mg/mL, and the quality of graphene oxide accounts for 1/3 of the quality of polyvinylpyrrolidone 0.5-0.9%.

Preferably, in step (1), the hydrothermal reaction temperature is 160-200°C, and the time is 12-20h; the vacuum drying temperature is 60-80°C, and the time is 6-12h.

Preferably, in step (2), the culture process of the bacterial liquid: inoculate Shewanella in advance and carry out initial aerobic culture under aerobic conditions, then take 10-20mL of aerobic cultured bacterial liquid and transfer to 100-200mL Aerobic culture was carried out again under the same conditions in the fresh medium.

Preferably, the culture medium used in step (2) is LB (Luria-Bertani) medium, more preferably, LB medium contains following composition: yeast extract 5g/L, tryptone 10g/L, sodium chloride 10g/L L, the pH value of LB medium is 6.8-7.2;

The time for the initial aerobic culture is 11-13h, and the time for the second aerobic culture is also 11-13h.

Preferably, in step (3), the concentration of the CdS/RGO material in the buffer A is 0.025-0.1g/L; when preparing the buffer A, the CdS/RGO material is dispersed in the anaerobic buffer by ultrasonic, and the ultrasonic Dispersion time is 40-60min;

After the precipitate obtained by centrifugation and the cells were transferred to buffer A, the OD600 value of Shewanella in the anaerobic buffer was 1-3, and the magnetic stirring time was 30-40 min.

Preferably, the anaerobic buffer solution used in step (3) is first subjected to aeration and deoxygenation and sterilization treatment, wherein the time for aeration and deoxygenation is 30-40 minutes, the sterilization temperature is 121° C., and the sterilization time is 20 minutes;

The anaerobic buffer contains 50mmol/L hydroxyethylpiperazine ethanesulfonic acid, 50mmol/L sodium chloride, 20mmol/L sodium lactate, 1mmol/L ascorbic acid, and the pH range is 6.8-7.2.

The invention also relates to a photocatalytic nanometer material-microbe hybrid, which is prepared by the above-mentioned preparation method.

The invention also relates to the application of the photocatalytic nano material-microbe hybrid in solar hydrogen production.

The beneficial effects of the present invention are:

1), the present invention utilizes microorganisms with excellent transmembrane electron transfer ability and hydrogen production ability, by adding two-dimensional nanomaterials with better biocompatibility and conductivity between inorganic photocatalytic materials and microbial cells as electron transfer media , to impose the combination of inorganic materials and biological cells and improve the interface electron transfer efficiency, so as to realize the efficient transfer of photogenerated electrons from extracellular to intracellular hydrogenase, so as to promote the efficiency of light energy utilization and hydrogen production efficiency;

2), compared with conventional IBSs, the novel IBSs constructed by the present invention can realize the efficient collection of photoelectrons and the rapid transmission between microbial cells; the CdS/RGO/MR-1 hybrid system constructed by the present invention has high stability , The advantages of high hydrogen production performance, the hydrogen production of the hybrid system in 12h is significantly greater than that of the CdS/MR-1 system and the MR-1 system, and the operation is simple, the preparation process is safe, and the cost is low;

3) The IBSs with high-efficiency electron transfer performance constructed by the present invention has broad application prospects in solar hydrogen production and other photocatalytic fields.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

The SEM topography image of CdS/RGO in Fig. 1 embodiment 1;

Figure 2: Figure A is the SEM image of CdS/RGO/MR-1 in Example 1; Figure B is the EDS-mapping image of C, O, Cd and S elements in the framed area of Figure A;

Figure 3 is the XRD patterns of CdS/RGO, CdS and RGO materials;

Figure 4: Figure A is the C1s spectrum of graphene oxide GO; Figures B to D are the C1s, Cd3d, S 2p spectrum of CdS/RGO in Example 1;

The impact of bacterial concentration and material concentration on hydrogen production performance in Fig. 5 embodiment 1;

Figure 6 is the cumulative hydrogen production diagram of different hybrid systems in Example 1 and Comparative Example 1-2;

The cumulative hydrogen production figure of the experimental group under the light situation and the control group under the dark situation in Fig. 7;

Figure 8 is the XRD pattern of CdS/RGO-MR-1 after the photocatalytic reaction in Example 1.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

The invention provides a method for preparing a photocatalytic nanomaterial-microbial hybrid, comprising the following steps:

(1) Take an appropriate amount of water-soluble divalent cadmium salt and thiourea) and polyvinylpyrrolidone (PVP) to dissolve in ethylene glycol to form a homogeneous mixed solution; wherein the water-soluble divalent cadmium salt is preferably cadmium chloride, divalent The concentration of cadmium salt is 90-100mmol/L, the concentration of thiourea is 90-100mmol/L, and the concentration of polyvinylpyrrolidone is 10-12mg/mL;

(2) An appropriate amount of graphene oxide is added to the mixed solution of step (1), hydrothermally reacted for a period of time (reaction temperature 160-200°C, time 12-20h), vacuum-dried after repeated washing with water and ethanol (temperature 60 -80°C, time 6-12h), prepare CdS/RGO material, wherein graphene oxide is added in the form of graphene oxide ethylene glycol solution, the concentration of graphene oxide ethylene glycol solution is 0.4-0.6mg/mL , the quality of graphene oxide accounts for 0.5-0.9% of the quality of polyvinylpyrrolidone;

(3) Pre-inoculate Shewanella with good activity and perform initial aerobic culture for 11-13 hours under aerobic conditions, transfer 10-20mL of aerobic cultured bacteria solution to 100-200mL of fresh culture solution under the same conditions Aerobic culture again for 11-13h; wherein the culture medium used is LB (Luria-Bertani) medium, more preferably, LB medium contains the following components: yeast extract 5g/L, tryptone 10g/L, sodium chloride 10g /L, the pH value of LB medium is 6.8-7.2;

(4) Prepare an anaerobic reactor equipped with anaerobic buffer medium, remove oxygen by exposing inert gas (argon), and sterilize after aeration; the medium contains the following components: 50mmol/L hydroxyethylpiperazine B Sulfuric acid, 50mmol/L sodium chloride, 20mmol/L sodium lactate, 1mmol/L ascorbic acid, the pH range is 6.8-7.2; the aeration time is 30-40min, the sterilization temperature is 121°C, and the sterilization time is 20min;

(5) Take an appropriate amount of the CdS/RGO material prepared in step (2) and add it to the anaerobic reactor of step (4), and disperse it evenly by ultrasound to obtain buffer A, the CdS/RGO material in buffer A The concentration is preferably 0.025-0.1g/L, more preferably 0.05g/L;

(6) Take an appropriate amount of Shewanella bacterium cultured in step (3) and centrifuge to discard the supernatant, then centrifuge to obtain the precipitate, wash it with buffered salt medium for 2-3 times, and then resuspend it, then transfer to step (5) ) buffer solution A, the OD600 value of Shewanella in the anaerobic buffer solution is 1-3, and the anaerobic reactor is further placed on a magnetic stirrer for mixing and stirring, and the magnetic stirring time is 30-40min to obtain light Catalytic nanomaterial-microbe hybrid system (CdS/RGO/MR-1 material).

Example 1

(1) Preparation of CdS/RGO: 3.5mmol of cadmium chloride (CdCl ₂ ^. 2.5H ₂ O) and 3.5mmol of thiourea (NH ₂ CSNH ₂ ) and 389mg of polyvinylpyrrolidone (PVP) were dissolved in 35mL of ethylene glycol Then add graphene oxide (5mL, 0.5mg/mL graphene oxide in ethylene glycol solution), ultrasonically form a homogeneous solution, after 160℃ hydrothermal reaction for 12h; centrifuge (10000rpm, 10min) to get a yellow precipitate ; Then, after washing with water and ethanol six times, vacuum drying at 80°C for 6 hours to obtain the CdS/RGO material;

(2) Cultivation of Shewanella: select strain Oneida Shewanella (Shewanella oneidensis MR-1); to 50mL LB medium (containing yeast extract 5g/L, tryptone 10g/L and chlorine Inoculate Shewanella species into NaCl 10g/L, pH=7), shake at 30°C for 12 hours at a constant temperature (200rpm) to obtain the bacterial liquid; transfer 20mL of the bacterial liquid to 200mL of fresh LB for culture at a volume ratio of 1:10 In the base, the bacterial liquid was obtained after continuing to activate for 12 hours under the same conditions;

(3) Preparation of CdS/RGO/MR-1: 1.5mg of CdS/RGO photocatalyst was dispersed in an anaerobic reactor with 30mL of anaerobic buffer solution (anaerobic buffer solution containing 50mmol/L hydroxyethyl Piperazine ethylsulfuric acid, 50mmol/L sodium chloride, 20mmol/L sodium lactate, 1mmol/L ascorbic acid, pH 7.0, anaerobic buffer solution is deoxygenated by exposure to inert gas (argon), sterilized after aeration, aeration The duration is 30-40min, the sterilization temperature is 121°C, and the time is 20min) to obtain buffer A; centrifuge the bacterial solution obtained in step (2), wash it twice with anaerobic buffer and resuspend it to suspend the bacteria solution was transferred to buffer A, the OD600 value of Shewanella in anaerobic buffer was 1, and the anaerobic reactor was stirred on a magnetic stirrer for 30min to obtain a photocatalytic nanomaterial-microbe hybrid system (CdS/ RGO/MR-1 material);

(4) Photocatalytic hydrogen production: The CdS/RGO/MR-1 mixed solution obtained in step (3) was illuminated, and the accumulated hydrogen content in the gas phase was detected every 4 hours using a gas chromatograph (GC-9790).

Comparative example 1

This embodiment also provides the synthetic method of pure CdS

The preparation process of CdS/RGO is basically the same as that of Example 1 step (1), except that the dosage of PVP is 0g, and the dosage of graphene oxide is also 0mg. For the CdS prepared in Comparative Example 1 Materials were characterized by XRD.

Cultivate Shewanella according to step (2) in Example 1, then replace the CdS/RGO material in Step (3) of Example 1 with the CdS material in this Comparative Example 1 to prepare the CdS/MR-1 material, The photocatalytic hydrogen production performance of CdS/MR-1 mixed solution was tested.

Comparative example 2

This embodiment also provides the synthetic method of pure RGO

The preparation process of CdS/RGO in step (1) of Example 1 is basically the same, except that only 40 mg of graphene oxide is dissolved in 20 mL of ethylene glycol, followed by hydrothermal reaction. The RGO material prepared in Comparative Example 2 was characterized by XRD.

Cultivate Shewanella according to step (2) in Example 1, then replace the CdS/RGO material in Step (3) of Example 1 with the RGO material in this Comparative Example 2 to prepare the RGO/MR-1 material, The photocatalytic hydrogen production performance of the RGO/MR-1 mixed solution was tested.

Carry out performance index test to the CdS/RGO/MR-1 inorganic biohybrid system prepared in embodiment 1

(1) Material and bacteria SEM characterization sample preparation

Take an appropriate amount of the CdS/RGO material synthesized in step (1) of Example 1, add 1mL of absolute ethanol to sonicate for 80-90min, and drop it on a silicon wafer for scanning electron microscope characterization.

Get 1 mL of the solution of the mixture in the anaerobic reactor in step (3) of Example 1 and centrifuge at a speed of 5000 g for 5 min, discard the supernatant, rinse 2 times with PBS, add 1 mL of 2.5% glutaraldehyde for fixation for more than 4 h. Use gradient ethanol (30%, 50%, 70%, 80%, 95%, 100%) for dehydration, remove the supernatant after centrifugation, resuspend with 1 mL of absolute ethanol, and drop the obtained solution on a silicon chip Scanning electron microscopy characterization.

Figure 1 is the SEM image of the CdS/RGO photocatalytic material synthesized in Example 1. It can be seen from the figure that CdS is evenly distributed on RGO, and RGO wraps CdS. Figure 2 shows the SEM image of CdS/RGO/MR-1 synthesized in Example 1 and the EDS-mapping images of C, O, Cd and S elements. It can be seen from the figure that RGO wraps CdS and then covers bacteria.

(2) XRD characterization sample preparation

Take an appropriate amount of CdS/RGO material synthesized in step (1) of Example 1 and the materials synthesized in Comparative Examples 1 and 2 for X-ray diffraction analysis and characterization. Figure 3 is the XRD spectrum of each material. By comparing the standard card (#77-2306), it shows that the phase of the nanomaterial synthesized in Comparative Example 1 is CdS; and there is no peak of RGO on the spectrum of CdS/RGO, which may be The reason is that the addition amount of RGO is small and the crystallinity is poor.

(3) XPS characterization sample preparation

Take an appropriate amount of CdS/RGO synthesized in step (1) of Example 1 for XPS characterization. Fig. 4 is the XPS spectrum of the material prepared in example 1, by analyzing the peak value of CdS/RGO composite material carbon, it is found that the percentage of CO and C=O of the composite material drops rapidly, thus proves the synthesis of RGO; The XPS of Cd 3d The spectrum presents two characteristic peaks at 403.9eV and 410.7eV, confirming that Cd in CdS behaves as Cd ²⁺ ; S2p ^1/2 and S2p ^3/2 orbitals are observed at 161.2eV and 162.8eV, respectively, indicating that S ² The existence of ^- ; combined with the results of SEM and XRD, it is proved that the synthesized material is CdS/RGO.

(4) Determination of optimal hydrogen production conditions

Referring to the mixed solution obtained in step (3) of Example 1, set the concentration gradient of different bacteria (OD600=1, 2, 3) and materials (0.025, 0.05, 0.1g/L), light the mixed solution, and use gas phase The chromatograph (GC-9790) detects the accumulated hydrogen content in the gas phase every 4h. Fig. 5 is an evaluation of the determination of the optimum hydrogen production conditions. It can be seen from the figure that the optimum hydrogen production conditions are bacterial concentration OD600 = 1 and material concentration 0.05g/L.

(5) Evaluation of the photocatalytic hydrogen production performance of inorganic biological mixtures

The CdS/RGO/MR-1 mixed solution obtained in step (3) obtained in Example 1, the CdS/MR-1 mixed solution obtained in Comparative Example 1, and the RGO/MR-1 mixed solution obtained in Comparative Example 2 were carried out respectively Photocatalytic hydrogen production test, Figure 6 shows the accumulated hydrogen content of the three experimental groups in different time periods. It can be seen from the figure that the composite catalyst described in the example of the present invention has a relatively high hydrogen production efficiency, and the accumulated hydrogen content in 12 hours is 12 times the sum of the cumulative hydrogen content of the CdS/MR-1 group and the RGO/MR-1 group .

(6) Hydrogen production performance test of the experimental group and the control group

Get the CdS/RGO material (without adding bacteria) obtained in step (1) of Example 1, the bacteria (without adding material) obtained in step (2) and the CdS/RGO/MR-1 obtained in step (3) are mixed The hydrogen production test was carried out under the environment of adding light (experimental group) and without adding light (control group) respectively.

Figure 7 shows the accumulated hydrogen content of the six experimental groups and the control group at different time periods. It can be seen from the figure that under light conditions, the accumulated hydrogen content of CdS/RGO/MR-1 described in Example 1 of the present invention at 12h is 22 times that of the pure bacteria group (MR-1).

(7) Sample preparation for XRD characterization after hydrogen production

Take the CdS/RGO/MR-1 mixed solution after photocatalytic hydrogen production (cumulative time is 24h) in step (4) of Example 1, centrifuge at 7000rpm for 10min, discard the supernatant bacterial solution, and place the collected precipitate in a vacuum drying oven Dry at 80°C for 6 hours; use an agate mortar to grind the dried solid into a uniform powder, and take an appropriate amount of powder for X-ray diffraction analysis and characterization. As shown in Figure 8, where CdS/RGO represents the CdS/RGO material synthesized in step (1) of Example 1, it can be seen from the XRD pattern that there is a peak of the CdS/RGO material in the reacted CdS/RGO-MR-1, And there is almost no change in the position of the peak. As for the broad peak at 2θ=20°, it is the peak of bacteria, and the presence of bacteria will reduce the peak intensity.

(8) ICP-AES test of Cd element concentration after hydrogen production

Take the solution before and after photocatalytic hydrogen production in step (4) of Example 1, centrifuge at 12000 rpm for 5 min, discard the precipitate and keep the supernatant. Digest the obtained supernatant, add 4mL nitric acid to boil at high temperature, then add 1mL perchloric acid, when the digestion tube emits thick white smoke, the digestion is over, the volume of the solution is fixed to 5mL, and the concentration of Cd in the solution is measured by ICP-AES . The calculation shows that the dissolution concentration of Cd element after the photocatalytic reaction is 0.045mg/L, and the dissolution rate is 0.09%. Combined with the XRD characterization results after photocatalytic hydrogen production, it shows that the inorganic biological hybrid system has good stability during the photocatalytic reaction.

It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and not to limit the present invention. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention. Furthermore, it is intended that the appended claims of the present invention embrace all changes and modifications that come within the scope and metesques of the appended claims, or equivalents of such scope and metes and bounds.

Claims (10)

1. A preparation method of photocatalytic nanomaterial-microorganism hybrid, is characterized in that, comprises the following steps: (1) Preparation of CdS/RGO Adding graphene oxide into a mixed solution containing water-soluble divalent cadmium salt, thiourea and polyvinylpyrrolidone, performing a hydrothermal reaction, then washing and vacuum drying to obtain a CdX/RGO material; (2) Culture of Shewanella Cultivate Shewanella under aerobic conditions to obtain a bacterial liquid; (3) Preparation of CdS/RGO/MR-1 Disperse the CdS/RGO material in the anaerobic buffer solution to obtain buffer solution A; centrifuge the supernatant of the bacterial liquid obtained in step (2), and then disperse the precipitate cells obtained by centrifugation into buffer solution A, mix and stir to obtain CdS /RGO/MR-1 material. 2. The preparation method according to claim 1, characterized in that, the water-soluble divalent cadmium salt is cadmium chloride. 3. preparation method according to claim 1 is characterized in that, the mixed solution that contains water-soluble divalent cadmium salt, thiourea and polyvinylpyrrolidone is solvent with ethylene glycol, and the concentration of divalent cadmium salt is 90- 100mmol/L, the concentration of thiourea is 90-100mmol/L, and the concentration of polyvinylpyrrolidone is 10-12mg/mL; in step (1), graphene oxide is added in the form of ethylene glycol solution of graphene oxide, graphene oxide The concentration of the ethylene glycol solution is 0.4-0.6mg/mL, and the mass of graphene oxide accounts for 0.5-0.9% of the mass of polyvinylpyrrolidone. 4. The preparation method according to claim 1, characterized in that, in step (1), the hydrothermal reaction temperature is 160-200°C, and the time is 12-20h; the vacuum drying temperature is 60-80°C, and the time is 6 -12h. 5. preparation method according to claim 1, is characterized in that, in step (2), the cultivation process of bacterium liquid: inoculate Shewanella in advance and carry out primary aerobic cultivation under aerobic condition, then take 10- Transfer 20mL of the aerobically cultured bacteria solution to 100-200mL of fresh culture solution and perform aerobic culture again under the same conditions. 6. preparation method according to claim 5, is characterized in that, the nutrient solution used in step (2) is LB culture medium; The time of initial aerobic cultivation is 11-13h, and the time of aerobic cultivation again is also 11h. -13h. 7. The preparation method according to claim 1, characterized in that, in step (3), the concentration of the CdS/RGO material in buffer A is 0.025-0.1g/L; centrifugally obtained sediment cells are transferred to buffer After A, the OD600 value of Shewanella in the anaerobic buffer solution is 1-3, and the magnetic stirring time is 30-40min. 8. The preparation method according to claim 1, characterized in that, the anaerobic buffer used in step (3) is first subjected to aeration and deoxygenation and sterilization. 9. A photocatalytic nanomaterial-microbe hybrid, characterized in that it is prepared by the preparation method according to any one of claims 1-8. 10. The application of the photocatalytic nanomaterial-microbe hybrid as claimed in claim 9 in solar hydrogen production.

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