Rhodamine B photocatalysis monitor based on visible light large-core-diameter end face reflection type optical fiber

Abstract

The invention discloses a rhodamine B photocatalysis integrated monitor based on a visible light large-core-diameter end face reflection type optical fiber, and belongs to the technical field of application of an optical fiber sensing technology to photocatalysis. The problems that an existing photocatalytic instrument is low in integration level, high in cost, insufficient in real-time monitoring capacity, remarkable in temperature-sensitive interference and the like are solved. The invention provides an integrated system architecture based on optical fiber sensing and intelligent measurement and control. Capturing a spectral signal of a catalytic reaction interface in real time through a modularized integrated broadband light source, a reflective optical fiber probe and a high-precision spectrum analyzer; the environment interference is eliminated by combining the self-adaptive temperature control unit, the dynamic adjustment of the reaction tank is realized by the intelligent lifting platform, and the multi-parameter collaborative analysis is completed by cooperating with the LabVIEW measurement and control platform, so that the photocatalytic monitor has the advantages of integration, multifunctionality, high sensitivity and the like, and the real-time monitoring of the photocatalytic process is realized, and meanwhile, the real-time monitoring of the photocatalytic process is realized. And a high-precision and integrated novel technical means is provided for in-situ monitoring of the catalytic interface reaction process and performance evaluation of the catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical field of applying fiber optic sensing technology to monitor photocatalytic reactions, and relates to an integrated instrument for reflectively fiber-optic real-time monitoring of the adsorption and degradation processes of photocatalytic rhodamine B. Background Art

[0002] Studying the pollutant degradation process is a core topic in the field of environmental protection. In-depth analysis of the pollutant degradation mechanism can not only optimize treatment strategies, improve the efficiency of environmental remediation, and significantly improve the environmental quality of the atmosphere, water bodies, and soil, but also help maintain ecological balance and reduce potential threats to biodiversity. Among many degradation technologies, photocatalytic degradation technology has attracted much attention due to its high efficiency, cleanliness, low cost, and pollution-free characteristics. However, traditional photocatalytic monitoring equipment generally suffers from technical bottlenecks such as insufficient system integration, high equipment cost, complex operation, poor real-time performance, and significant temperature-sensitive interference. An integrated system architecture based on fiber optic sensing and intelligent measurement and control has been constructed. The system innovatively realizes the real-time in-situ tracking of the catalyst reaction process, dynamically regulates the reaction temperature through a high-precision temperature control chip, and uses an adaptive motor system to achieve precise temperature control, significantly simplifying the equipment debugging process. The system is built-in with an intelligent processor that can synchronously analyze experimental data and visually present it. Combining with the intelligent control platform constructed by LabVIEW software, it realizes the full-process integration of equipment operation, data acquisition, and in-depth analysis, providing an intelligent and high-precision innovative solution for photocatalytic technology research.

[0003] Surface plasmon resonance (SPR) is an advanced detection technology based on optical principles. By monitoring the changes in the surface plasmon resonance phenomenon in the sensing area, it can reflect the binding or separation state of biomolecules in real time and achieve quantitative analysis of molecular interactions. This technology requires no labeling, has high sensitivity, and can be monitored in real time. Photocatalysis is a technology that uses light energy to drive chemical reactions. Its core is to absorb photons through semiconductor materials to generate electron-hole pairs, thereby triggering redox reactions. The photocatalytic monitor integrates an SPR sensor and a catalytic device, featuring high integration, versatility, and high sensitivity. Its core advantage lies in realizing platform control and data analysis through LabVIEW software, supporting in-situ real-time monitoring of visible light large-core diameter end-face reflective fiber optic photocatalytic reactions, and being able to accurately capture the dynamic reactions during the adsorption and desorption processes on the catalyst surface. The application of this technology will significantly promote innovation in the field of photocatalytic monitoring and provide efficient and convenient detection means for fields such as environmental monitoring and biomedicine. Summary of the Invention

[0004] In order to improve the problems of insufficient integration of existing photocatalytic instruments, high equipment cost, complex data processing, inability to monitor in real time, and significant temperature-sensitive interference, the present invention provides a multifunctional integrated photocatalytic monitor based on a visible-light large-core-diameter end-face reflective optical fiber. The SPR technology based on optical fiber sensing is adopted, and by monitoring the shift of the resonance wavelength, the instant monitoring and analysis of the reaction process are realized. The photocatalytic monitoring instrument modularly integrates various functional modules through LABVIEW software, such as a display module, a data acquisition module, an analysis module, a control module, and an adaptive temperature control module, etc. It integrates a broadband light source, a reflective optical fiber probe, and a high-precision spectrometer to capture the spectral signals of the catalytic reaction interface in real time; combines an adaptive temperature control unit to eliminate the interference of the ambient temperature; uses an intelligent lifting platform to realize the dynamic adjustment of the reaction cell, and cooperates with the LabVIEW measurement and control platform to complete the collaborative analysis of multiple parameters. At the same time, the instrument is equipped with an intelligent processor to realize the synchronous analysis of data and an intuitive data display interface, improving the readability and analyzability of the data. The photocatalytic monitor based on the reflective optical fiber reduces the cost and usage threshold of the instrument, and while realizing the real-time monitoring of the photocatalytic process, it provides a more convenient and efficient detection solution for the in-situ monitoring of the catalytic interface reaction process and the performance evaluation of the catalyst.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A monitoring instrument for real-time monitoring of photocatalytic ability, the instrument includes a light source, a spectrometer, an intelligent lifting platform, a reflective optical fiber SPR sensor, an optical fiber coupler, a 1×2 Y-shaped optical fiber jumper, a microprocessor, a temperature control module, a temperature measurement probe, a microcontroller, a display module, an ultraviolet lamp, and a power supply module. The light source is connected to the Y-shaped optical fiber jumper. The double-head ends of the Y-shaped optical fiber are respectively connected to the spectrometer and the optical fiber sensor through SMA905 interfaces, and the optical fiber sensor is fixed by an optical fiber fixture; the output end of the spectrometer is connected to the USB interface of the Intel NUC 11 Essential microprocessor through a connection line; the spectrometer and the processor are connected through a serial communication line; the temperature control chip, the ultraviolet lamp, the temperature measurement probe, and the lifting platform are connected to the microcontroller single-chip interface; the power supply module is used to provide working power for the microprocessor, the intelligent lifting platform, the light source, the spectrometer, the ultraviolet lamp, and the temperature control chip; all functions are integrated into the front panel of the LABVIEW software to realize functions such as synchronous processing, display, and storage of data.

[0007] Further defined, the system controls the lifting stroke of the lifting platform. When the total stroke of the lifting platform is 100 mm, the speed range is 5 mm / s, and the torque is 2000 N, a DC12 V DC power supply is adopted.

[0008] Further defined, the temperature control module of the photocatalytic monitor intelligently displays the temperature. The input voltage range applicable to the DC temperature control automatic temperature and voltage regulation module is from DC12 V to 50 V, the maximum output power is 30 A, and it is limited within 20 A during long-term use. The monitoring instrument has a temperature control range of -40°C to 120°C, a temperature control accuracy of ±0.1°C, and uses an NTC thermistor with a model of 3950, a resistance value of 10 K, and a temperature measurement air probe with an accuracy of 1%.

[0009] Further defined, the power of the external catalytic light source is 120 W, the wavelength is 335 nm - 390 nm, and the placement position is 3 cm away from the horizontal position of the fiber optic SPR sensor.

[0010] The preparation method of the fiber optic SPR sensor includes the following steps:

[0011] Step 1, select a multi-mode fiber with a core diameter of 600 μm and a numerical aperture of 0.37 as the base material, and cut it into a standard length of 9 cm.

[0012] Step 2, perform local modification treatment at the head end of the fiber. Precision remove the polymer protective layer and cladding structure of the 2 mm section to fully expose the core. Use the magnetron sputtering process to synchronously deposit a silver metal layer with a thickness of 300 nm on the side wall and end face of the exposed core, and then perform ultraviolet photosensitive resin coating and photocuring treatment to form a composite silver film reflection interface.

[0013] Step 3, then at an axial position 15 mm away from the silver film interface at the head end, perform a secondary cladding removal operation with a length of 10 mm to construct a bare core sensing area. Use a magnetron sputtering coater to sputter a 50nm thick gold nanolayer on the side of the core to form a surface plasmon resonance sensitive interface.

[0014] Step 4, finally perform surface modification on the gold-plated sensing area. Orientally fix the titanium dioxide photocatalyst on the gold film surface through chemical coupling technology to form a functionalized sensing interface with photocatalytic activity. This process requires strict control of the coupling agent concentration and reaction time to ensure the uniform distribution and stable binding of the catalyst nanoparticles.

[0015] Further defined, the end face of the core obtained in Step 2 is placed on diamond abrasive sandpaper (8000 mesh, 10000 mesh, and 12000 mesh) for planar grinding to eliminate the microscopic unevenness caused by cutting. Place the ground fiber in a plasma cleaner and process it at a power of 50 W for 5 min to effectively remove surface organic pollutants and activate the hydroxyl active sites on the core surface, improving the adhesion of the subsequent silver film.

[0016] Further defined, the specific operation process of Step 4 is as follows: S1. Activation and modification of the sensing interface: Accurately prepare a 5 mM ethanolic solution of mercaptoundecanoic acid (MUA) (V / V = 1:9), and then mix it with a magnetic stirrer at 25 °C and 800 rpm until the solution becomes clear (about 30 min); finally, vertically immerse the gold-plated optical fiber into the solution, seal it in the dark, and let it stand for 12 h to form a self-assembled monolayer with terminal carboxylic acid functional groups; after standing, take it out, rinse it alternately with ultrapure water and ethanol 3 times, and dry it with nitrogen purge for standby. S2. Amination modification of the catalyst surface: Take 50 mg of anatase TiO2 powder (particle size 20 nm) and mix it with 10 mL of absolute ethanol, and ultrasonically disperse it for 30 min until no visible agglomeration; while mechanically stirring (500 rpm), dropwise add 3-aminopropyltriethoxysilane with a concentration of 98%, and mix it evenly with an adjustable vortex mixer (3000 rpm) for 20 min and then let it stand for 12 h to complete the amination functionalization modification of the TiO2 surface. After that, take out the supernatant of the dispersion after standing in S2, wash the precipitated catalyst TiO2 with absolute ethanol, transfer the washed dispersion to a centrifuge tube, and centrifuge it for 10 min with a centrifuge speed of 9000 r; S4. Dissolve the centrifuged catalyst TiO2 in S3 in absolute ethanol to make a dispersant for the catalyst TiO2, place the treated optical fiber sensing area in S1 in the dispersant of the catalyst TiO2 for 30 min, take it out, and dry the optical fiber surface in an oven at 80 °C for 30 min to obtain an optical fiber SPR sensor modified with the catalyst TiO2.

[0017] Further limitation: The concentration of the mercaptoundecanoic acid solution obtained in step S1 is 5 mM.

[0018] Further limitation: The mass concentration of the ethanol solution in step S2 is 10%, the mass concentration of the dropwise added 3-aminopropyltriethoxysilane in the dispersion is 5%, and the volume ratio of absolute ethanol, deionized water, and 3-aminopropyltriethoxysilane is 1:10:0.5.

[0019] The present invention has the following beneficial effects: The present invention provides a rhodamine B photocatalytic integrated monitor based on a visible-light large-core diameter end-face reflective optical fiber. By combining the catalyst TiO2 on the optical fiber sensing area using a chemical coupling method, based on the surface plasmon resonance (SPR) principle, the real-time monitoring and analysis of the photocatalytic interface reaction process are realized.

[0020] First, the rhodamine B photocatalytic integrated monitor based on the visible-light large-core diameter end-face reflective optical fiber of the present invention can monitor the photocatalytic reaction process in the optical fiber SPR sensor while avoiding the problem of environmental temperature crosstalk.

[0021] The present invention constructs a terminal amino functional layer on the surface of the fiber optic sensing region through a silane coupling agent (APTES), achieving the directional covalent fixation of the TiO2 catalyst and improving the overall performance and stability of the modified TiO2 catalyst.

[0022] Furthermore, the directional modification of the TiO2 catalyst at the sensing interface as described in the present invention enables the in-situ dynamic monitoring of the entire process of rhodamine B molecule adsorption-catalytic degradation. With the ultra-high sensitivity of the SPR signal to the interface refractive index, the system can capture in real-time the microscopic kinetic processes such as the desorption of pollutant molecules on the TiO2 surface, and obtain the real-time in-situ changes of the TiO2 catalyst during the catalytic process.

[0023] Finally, the integrated photodegradation monitoring instrument of the present invention adopts a modular integrated design, equipped with an intelligent operation platform and a high-definition visual data interface, realizing a comprehensive upgrade of the detection process. By introducing intelligent algorithms and data processing technologies, the data processing process is simplified, and intuitive monitoring results are provided. The operation process is simplified by integrating various functional modules, and the simple operation allows users to easily set parameters. At the same time, the instrument is designed with an intuitive data display interface, enabling users to clearly view the detection results, improving the readability and analyzability of the data. These features make the photodegradation monitoring instrument more convenient and efficient, providing an intelligent full-process solution for the performance evaluation of photocatalytic materials and the research of reaction mechanisms, and strongly promoting the scientific research innovation and industrial application process of photocatalytic technology. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of a monitoring instrument system for monitoring the adsorption and degradation process of photocatalytic rhodamine B;

[0025] Figure 2 It is a flowchart of the integrated program design of an integrated photocatalytic device;

[0026] Figure 3 It is a panel diagram of the SPR monitoring program of an integrated photocatalytic device;

[0027] Figure 4 It is a schematic structural design diagram of a reflective optical fiber;

[0028] Figure 5 is a sensitivity test diagram of the reflective optical fiber;

[0029] Figure 6 It is a test diagram of the photocatalytic rhodamine B adsorption and degradation process of the reflective optical fiber;

[0030] Figure 7 It is the temperature response of the temperature compensation optical fiber;

[0031] Figure 8 It is the first-order kinetic analysis during the test process of the reflective optical fiber; DETAILED DESCRIPTION

[0032] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0033] Embodiment 1:

[0034] Preparation of silver film reflection area: select a multimode optical fiber with a core diameter of 600 μm and a numerical aperture of 0.37, cut it into a standard length of 9 cm, remove 2 mm of the coating and cladding 17 at one end of the optical fiber, use #diamond abrasive sandpaper to plane grind the exposed core end face, then place the optical fiber in a plasma cleaner for cleaning, and finally use a magnetron sputtering coater to attach a 300 nm silver reflection film to the side and end face of the optical fiber core, then coat it with low refractive index UV curing glue (n=1.38), and cure it with 365 nm UV light for 30 s to form a protective layer to prevent the silver reflection film from generating SPR signals, and obtain the silver film reflection area 15.

[0035] Preparation of optical fiber sensing area: Remove 10 mm of the optical fiber coating and cladding 21 at 15 mm of the silver film reflection area 19 obtained above to form a bare fiber sensing area, and then deposit a 50 nm gold film by ion beam sputtering. The optical fiber without catalyst modification is used as a temperature compensation optical fiber SPR sensor 13.

[0036] Modify the surface of the sensing area with catalyst TiO2: weigh 5.4589 mg of mercapto undecanoic acid and mix it with 5 mL of anhydrous ethanol, use a stirrer to fully dissolve it, and obtain a 5 mM ethanol solution of mercapto undecanoic acid. Place the optical fiber sensing area 18 in the ethanol solution of mercapto undecanoic acid, place it in a light-proof place and seal it for 12 h. At the same time, weigh 4.8 mg of TiO2 powder with a purity of 97%, add 10 mL of 10% ethanol solution by mass, and ultrasonically disperse it for 30 min. Add 0.5 mL of 98% 3-aminopropyltriethoxysilane dropwise to the obtained TiO2 dispersion, stir and disperse it with an adjustable vortex mixer for 20 min, and let it stand for 12 h. After standing, use a pipette to take out the supernatant of the TiO2 dispersion, wash the precipitated TiO2 with anhydrous ethanol, and place the washed TiO2 dispersion in 4 centrifuge tubes with a capacity of 2.5 mL, respectively, and centrifuge it with a centrifuge at a speed of 9000. The centrifuged TiO2 was dissolved in 10 mL of anhydrous ethanol to prepare 10 mL of TiO2 dispersant. The soaked optical fiber sensing area 18 was placed in the TiO2 dispersant for 30 min, taken out, and dried in a drying oven at 80°C for 30 min. Finally, the optical fiber SPR sensor 3 was obtained.Figure 4 as shown

[0037] Preparation of Rhodamine B solution: Weigh 20 mg of Rhodamine B. Add 100 mL of deionized water to a 150 mL beaker. Pour the weighed Rhodamine B into the deionized water and stir well until Rhodamine B is completely dissolved to obtain a 0.2 mg / mL Rhodamine B solution.

[0038] Optical fiber integrated monitor for in-situ monitoring of the photocatalytic adsorption and degradation process of Rhodamine B: As Figure 1 shown, the optical fiber SPR sensor and the temperature compensation optical fiber SPR sensor: The optical fiber SPR sensor 3 is connected through the jumper SMA-905 coupler 4 of the first Y-shaped optical fiber 6. The two ends of the coupler are respectively connected to the first halogen light source 1, HL-2000 and the first spectrometer 5, Ocean Optics, HR4000. The temperature compensation optical fiber SPR sensor 13 is connected through the jumper SMA-905 coupler of the second Y-shaped optical fiber 16. The two ends of the coupler are respectively connected to the second halogen light source 14, HL-2000 and the second spectrometer 15, Ocean Optics, HR4000. The single-chip microcontroller is connected to the temperature control chip, the temperature measuring air probe and the lifting platform. Fixing of the sensor and the photocatalytic reaction device: The optical fiber SPR sensor 3 and the temperature compensation optical fiber SPR sensor 13 are fixed in the Rhodamine B solution by clamps to ensure full contact between the sensor and the solution. The external catalytic light source is horizontally placed 3 cm away from the Rhodamine B solution to provide the required light conditions for the photocatalytic reaction. Through the above structure, the optical fiber integrated monitor can realize in-situ real-time monitoring of the photocatalytic adsorption and degradation process of Rhodamine B.

[0039] The working principle of the application system of the optical fiber SPR sensing sensor for real-time monitoring of the photocatalytic adsorption and degradation process of Rhodamine B is: As Figure 1 and Figure 4As shown in the figure, after the incident light 22 emitted by the first halogen light source 1 enters the fiber optic SPR sensor 3, total internal reflection occurs in the optical fiber, and the surface plasmon resonance (SPR) phenomenon is excited on the gold film surface of the fiber optic sensing area 18. The SPR effect generates an evanescent wave on the surface of the fiber optic sensing area. This evanescent wave can penetrate the surface of the sensing area to highly sensitively monitor the material changes occurring on the surface. The entire reaction change process of the pollutant substrate is divided into two parts: Adsorption stage: Under the condition of non-catalytic light illumination, rhodamine B molecules are adsorbed onto the surface of the catalyst TiO₂ 20. Degradation stage: Under the action of an external catalytic light source, the rhodamine B molecules adsorbed on the surface of TiO₂ 20 are photocatalytically degraded. Since the SPR effect is very sensitive to the refractive index change on the surface of the sensing area, when the refractive index increases, the resonance wavelength shifts towards the long wavelength direction (red shift); when the refractive index decreases, the resonance wavelength shifts towards the short wavelength direction (blue shift). Since the refractive index of rhodamine B (1.6500) is greater than that of deionized water (1.3330), the adsorption process will cause a red shift in wavelength, while the degradation process will cause a blue shift in wavelength. Therefore, by real-time monitoring the shift of the resonance wavelength through the fiber optic SPR sensor, the adsorption and degradation processes of rhodamine B on the catalyst surface can be accurately reflected, thereby realizing in-situ real-time monitoring of the photocatalytic reaction.

[0040] The above-mentioned instrument was used to monitor the adsorption and degradation processes of photocatalytic rhodamine B, and the experimental data were analyzed.

[0041] Figure 5a This is the SPR response curve under non-catalytic light illumination conditions using the signal acquisition system 10 with different refractive indices of NaCl. The SPR curve is very sensitive to the refractive index change on the surface of the fiber optic sensing area 18. From Figure 5a it can be seen that as the refractive index increases, the resonance wavelength of the SPR curve moves towards the direction of increasing wavelength (red shift). The Figure 5b obtained by linearly fitting the resonance wavelength change of the SPR curve under gradient refractive indices reflects the sensitivity of the sensor, and the sensitivity is 2030.8 nm / RIU.

[0042] Figure 6 This is the test result of the fiber optic SPR sensor during the adsorption and degradation processes of photocatalytic rhodamine B. From Figure 6 it can be seen that during the adsorption process: Under the condition of non-catalytic light illumination, rhodamine B molecules are adsorbed onto the surface of the fiber optic sensing area 18 through free diffusion and combine with the catalyst TiO₂ 20 on the sensing area. This process causes a local increase in the refractive index on the surface of the sensing area, resulting in a red shift in the resonance wavelength and gradually reaching a saturated state.

[0043] During the degradation process: When the external UV catalytic light source 11 is turned on, the rhodamine B molecules adsorbed on the surface of the catalyst TiO2 20 are decomposed under photocatalysis, resulting in a decrease in the local refractive index and a blue shift in the resonance wavelength, and finally reaching a stable state. Figure 7 This is the temperature response curve of the temperature-compensated fiber optic SPR sensor 13 under the action of the external catalytic light source 11. When the light source is turned on, the temperature rises rapidly, and the resonance wavelength undergoes a blue shift due to the thermal effect. Subsequently, as the temperature approaches equilibrium, the wavelength change also gradually stabilizes. To eliminate the influence of the photothermal effect on the test results, Figure 6 the temperature response during the adsorption and degradation of rhodamine B in Figure 7 is obtained by subtracting the temperature compensation curve in

[0044] Figure 8 This is the first-order kinetic analysis result during the test of the fiber optic SPR sensor. Here, λ0 in the vertical coordinate represents the total red shift of the wavelength during the adsorption process of rhodamine B, and Δ λ represents the real-time blue shift during the adsorption and degradation of rhodamine B. By substituting the wavelength shift data monitored by the fiber optic SPR sensor 3 during the photocatalysis process into the first-order kinetic calculation formula, the change rate of the first-order kinetic constant K during the degradation process can be obtained. This result shows that the invented integrated photocatalysis instrument based on reflective optical fiber can effectively analyze and monitor the adsorption and degradation processes of photocatalytic rhodamine B in real time.

Claims

1. A rhodamine B photocatalytic integrated monitor based on a visible-light large-core diameter end-face reflective optical fiber, characterized in that, The described photocatalytic monitor system includes a first halogen light source (1), an intelligent lifting platform (2), a reflective fiber optic SPR sensor (3), an optical fiber coupler (4), a first spectrometer (5), a first 1×2 Y-type fiber optic jumper (6), a microprocessor (7), a temperature control module (8), a display module (9), a power supply module (10), an ultraviolet lamp (11), a single-chip microcontroller (12), a temperature compensation fiber optic sensor (13), a second halogen light source (14), a second spectrometer (15), a second 1×2 Y-type fiber optic jumper (16), and a temperature-measuring air probe (17); the optical signal output by the first halogen light source (1) passes through the 1×2 Y-type fiber optic jumper (6), then through the reflective fiber optic SPR sensor (3), and then through one port of the first 1×2 Y-type fiber optic jumper (6) to be input to the optical signal acquisition end of the first spectrometer (5), and the double-headed end of the Y-type fiber optic is connected to the light source (1) and the spectrometer (5) respectively through the optical fiber coupler (4); the spectrometer is connected to the microprocessor (7) through serial communication, and the output end of the spectrometer is connected to the USB interface of the microprocessor (7) through a connecting wire; the single-headed end of the second 1×2 Y-type fiber optic (16) is connected to the temperature compensation fiber optic SPR sensor (13); the temperature control chip (8), the temperature-measuring air probe (17), the ultraviolet lamp (11), and the lifting platform (2) are connected to the single-chip microcontroller interface of the microcontroller (10); the power supply module (10) is used to provide working power for the microprocessor (7), the light source (1), the intelligent lifting platform (2), the spectrometer (5), the ultraviolet lamp (11), and the temperature control chip (8).

2. The rhodamine B photocatalytic integrated monitor based on a visible-light large-core diameter end-face reflective optical fiber according to claim 1, characterized in that, The system controls the total lifting stroke of the intelligent lifting platform (2) to be 100 mm, the speed range is 5 mm / s, the torque is 2000 N, and it uses a DC12V DC power supply.

3. The rhodamine B photocatalytic integrated monitor based on a visible-light large-core-diameter end-face reflective optical fiber according to claim 1, characterized in that The input voltage range of the temperature control module (8) is DC12 V to 50 V, the maximum output power is 30 A, and it is limited within 20 A during long-term use. The temperature control range is -40°C to 120°C, and the accuracy is ±0.1°C.

4. The rhodamine B photocatalytic integrated monitor for visible light large core diameter end-face reflective optical fiber according to claim 2, characterized in that, An acquisition and analysis system suitable for a multi-channel fiber optic SPR sensing system is designed based on the LabVIEW programming language, which is mainly used to collect complete spectral information of independent detection channels in real time and has functions such as synchronous processing, display, and storage of data. The data processing system processes and analyzes the data obtained by the detector to realize real-time monitoring and analysis of the photocatalytic reaction process.

5. The rhodamine B photocatalytic integrated monitor for visible light large core diameter end-face reflective optical fiber according to claim 2, characterized in that The spectrometer (5) is an ultraviolet-visible spectrometer, which integrates a micro spectrometer array with a USB 2.0 interface. The single-channel spectral transmission rate is 250 spectra / s, the wavelength range is 400 - 1100 nm, the integration time range is 0 - 100 ms, the accuracy is 0.1 nm. When the integration time is set to 10 ms, the sampling interval time is 0.25 s, and the spectral sampling range is limited to 0 - 3648 pixels.

6. The rhodamine B photocatalytic integrated monitor based on a visible-light large-core diameter end-face reflective optical fiber according to claim 1, characterized in that The output power of the light source (1) can be adjusted through the software front panel buttons. By adjusting the working current of the excitation light source (1), precise control of the output power of the light source (1) can be achieved, providing a reliable light source signal for subsequent photocatalysis experiments and research work.

7. The photocatalytic integrated monitor according to claim 1, wherein An embedded microprocessor (7) powered by 12 V DC uses an Intel NUC 11 Essential mini PC, integrating an 11th-generation Celeron processor and dual-channel DDR4 memory; a multi-protocol data acquisition module connects to a spectrometer array through a USB 2.0 interface, supports synchronous acquisition of 4-channel spectral data, and the transmission rate is ≥10 Gbps; The display module is configured with a 4.2-inch IPS capacitive screen, with a resolution of 1920×1080, and the adjustable brightness range is 50 - 500 cd / m².

8. The rhodamine B photocatalytic integrated monitor for visible light large core diameter end-face reflective optical fiber according to claim 2, characterized in that, The ultraviolet lamp (11) is used as an external catalytic ultraviolet light source, with a power of 120 W and a wavelength of 365 nm.

9. The rhodamine B photocatalytic integrated monitor for visible light large core diameter end-face reflective optical fiber according to claim 6, characterized in that, The temperature-measuring air probe (17) monitors the photocatalytic reaction temperature in real time and displays it on the display screen, and then transmits the temperature signal to the single-chip microcontroller (12); the microcontroller (12) dynamically adjusts the rotation speed of the cooling fan according to the temperature threshold preset by the temperature control module (8), so that the reaction temperature is stabilized in the range of 25±0.5 °C to eliminate the interference of temperature fluctuations on the photocatalytic detection results.

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