Photocatalyst surface photogenerated radical detection device and detection method

Abstract

The application relates to the field of photocatalyst detection, in particular to a photocatalyst surface photogenerated radical detection device and a detection method. The device comprises a reactor main body, a light source module arranged above the reactor main body, a radical detection module arranged below the reactor main body, a reaction cavity arranged in the reactor main body, a reaction panel arranged in the reaction cavity, a groove arranged on the reaction panel and used for placing photocatalyst particles, a through hole arranged in the center of the reaction panel and used for allowing radicals to flow downward, and the reaction panel can vibrate up and down along the illumination direction. The reactor main body has a stepped surface, an elastic connecting piece is arranged between the stepped surface and the bottom surface of the reaction panel, a vibration generator is arranged on the reactor main body, and a negative pressure nozzle is arranged at the bottom of the reactor main body. The vibration of the reaction panel under the driving of nitrogen gas can make the particles turn over and expose, improve the uniformity of illumination, form a centripetal air flow, improve the transmission efficiency of radicals, and improve the detection effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photocatalyst detection, in particular to a device and method for detecting photogenerated radicals on the surface of a photocatalyst. BACKGROUND

[0002] Photocatalysis technology has important applications in environmental purification, energy conversion, etc. The core of photocatalysis technology is that photocatalysts generate free radicals with strong redox ability under light irradiation, which participate in the degradation of pollutants or drive chemical reactions. In order to evaluate the performance of photocatalysts, it is crucial to accurately detect the types and concentrations of free radicals generated on the surface of photocatalysts. Current commonly used methods include electron paramagnetic resonance, fluorescence probe method, chemical trapping combined with chromatographic analysis, etc. These techniques indirectly reflect the generation of free radicals by trapping the reaction products of free radicals and probe molecules. However, the existing detection methods generally have problems such as short free radical lifetime, easy quenching, low detection sensitivity, and difficulty in realizing real-time in-situ monitoring.

[0003] The currently disclosed Chinese patent CN115825021B discloses a device and method for quantitatively detecting surface photocatalytic radicals of particulate matter, which includes a light source module, a reaction module, a gas distribution system, a free radical detection module, and a control system. The light source module is used to generate photolysis light beams or simulate natural light beams and irradiate them into the reaction module. The photolysis light beams are used to photolyze free radical precursors to generate free radicals. The simulated natural light beams are used to irradiate the surface of particulate matter to generate free radicals through photocatalysis. The gas distribution system is connected to the reaction module and is used to introduce free radical precursor synthesis gas into the reaction module. The reaction module is the site where free radicals are generated. The photolysis light beams from the light source module are used to photolyze the free radical precursor synthesis gas to generate free radicals. Alternatively, the simulated natural light beams from the light source module are used to photocatalyze the particulate matter samples placed in the reaction module to generate free radicals. Alternatively, sunlight is directly irradiated into the reaction module to photocatalyze the particulate matter samples placed in the reaction module to generate free radicals. The reaction module is connected to the free radical detection module, and the free radicals generated in the reaction module enter the free radical detection module. The free radical detection module is used to emit laser light to the free radicals to excite them to generate fluorescence, and is used to collect fluorescence photon signals and outgoing laser energy. The control system is used to receive various data collected in the device, control various controllable devices in the device, and perform relevant calculation tasks.

[0004] According to the above-mentioned patent, the gas flow blown out of the air outlet hole is uniformly pushed from all around to the top of the reaction panel, and the free radicals generated on the surface of the particulate matter sample under photocatalysis are blown down to the vicinity of the sampling nozzle of the free radical detection module without dead angles, driving the free radicals generated on the surface of the particulate matter sample in the reaction module under photocatalysis to enter the free radical detection module.

[0005] However, when particles are laid out, the upper layer blocks the lower layer, preventing it from receiving sufficient light, which affects the amount of free radicals generated and the representativeness of the measurement results. Simultaneously, continuous lateral airflow can cause particle disturbance or even scattering, affecting the uniformity of illumination and the stability of the measurement. Therefore, there is a need for a photocatalyst surface photogenerated free radical detection device that can overcome the problems of particle accumulation blocking and airflow disturbance. Summary of the Invention

[0006] To address the problems existing in the prior art, a photocatalyst surface photogenerated free radical detection device is provided. By vibrating the reaction panel under nitrogen-driven conditions, the particles are turned over and exposed, improving the uniformity of illumination and forming a centripetal airflow. This, combined with negative pressure, enhances the free radical transport efficiency and improves the detection effect.

[0007] To address the problems of existing technologies, this invention provides a photocatalyst surface photogenerated free radical detection device, comprising a reactor body, a light source module located at the top of the reactor body, and a free radical detection module located at the bottom. The reactor body contains a reaction chamber connected to the free radical detection module, and a reaction panel is provided within the reaction chamber. The reaction panel has grooves for placing photocatalyst particles, and a through-hole is provided at the center of the reaction panel along the light direction for free radicals to flow downwards. The reaction panel can vibrate up and down along the light direction. The reactor body has a stepped surface with a gap between the stepped surface and the reaction panel. An elastic connector is provided between the stepped surface and the bottom surface of the reaction panel. A vibration generator is provided on the reactor body to drive the reaction panel to vibrate periodically. When the vibration generator is activated, the reaction panel gradually moves downwards under the driving force, while the elastic connector is in a compressed energy storage state. When the vibration generator is intermittently stopped, the elastic connector causes the reaction panel to gradually rebound, forming reciprocating vibration. A negative pressure nozzle is provided at the bottom of the reactor body to introduce free radicals from the reaction chamber into the free radical detection module.

[0008] Preferably, a light-transmitting panel is fixedly provided on the top of the reaction panel to prevent particles from falling out of the groove, and the surface of the light-transmitting panel has a plurality of diffusion slots for free radicals to flow through.

[0009] Preferably, the vibration generator includes an air duct opened on the reactor body and communicating with the reaction chamber, and a pressure block set opposite to the air duct. Several air ducts are evenly distributed around the reactor body. A pressure block is fixedly provided on the edge of the reaction panel corresponding to each air duct. The side of the pressure block facing the air duct has a chamfer structure.

[0010] Preferably, the ventilation direction of each air channel is perpendicular to the axial direction of the through hole, and when the air channel ventilation acts on the pressure block, the free radicals gradually converge to the central area under the action of the airflow, and the negative pressure nozzle cooperates to form a synergistic airflow field with the upper part converging and the lower part vertically sucking.

[0011] Preferably, the airflow ventilated by each air channel is nitrogen.

[0012] Preferably, the elastic connecting piece comprises a compression spring, a sleeve vertically downwardly extending on the inner side of the reaction panel, and a ring sleeve fixedly arranged on the reactor body and sleeved on the sleeve, and the compression spring is sleeved on the sleeve and located between the reaction panel and the ring sleeve, and the two ends of the compression spring are further fixedly connected with the reaction panel and the ring sleeve respectively.

[0013] Preferably, the elastic connecting piece further comprises a sealing washer coaxially arranged with the sleeve, and the upper and lower end faces of the sealing washer are tightly attached to the reaction panel and the stepped surface respectively, and when the reaction panel moves downward, the sealing washer is in a self-adaptive compression deformation state.

[0014] Preferably, the top of the reactor body is provided with a light filtering panel.

[0015] Preferably, a telescopic mesh cover is arranged between the light filtering panel and the reaction panel to prevent some small particles from being carried by the airflow, the light filtering panel is provided with an upper fixed part, the sleeve is provided with a lower fixed part, the telescopic mesh cover is provided with an upper buckle and a lower buckle at the upper end and the lower end respectively, and the upper fixed part and the lower fixed part are respectively provided with a clamping groove matched with the corresponding buckle.

[0016] The application further provides a method for detecting surface photogenerated radicals of a photocatalyst, comprising the following steps:

[0017] S1, placing the photocatalyst particles into the groove of the reaction panel, covering the light-transmitting panel, and starting the light source module to irradiate, so as to excite the particles to generate free radicals on the surface;

[0018] S2, driving the reaction panel to reciprocatingly vibrate up and down by periodically starting and stopping the vibration generator, so as to make the particles tumble to be fully exposed to the light;

[0019] S3, introducing nitrogen into the air channel to impact the pressure block, driving the reaction panel to vibrate, and using the negative pressure nozzle to form a synergistic airflow field of converging and vertically sucking in the reaction cavity;

[0020] S4, the free radicals are transported downward to the free radical detection module along with the airflow through the through hole, the fluorescence is excited by laser, and the signal is detected to realize quantitative analysis.

[0021] The beneficial effects of the present application compared with the prior art are:

[0022] 1. The present application promotes the micro-displacement and turnover of particulate matter through the reciprocating vibration of the reaction panel, breaks the accumulation and shielding, and fully exposes the surface of deep-layer particles to light, thereby improving the uniformity of light and the efficiency of catalytic reaction.

[0023] Meanwhile, through the light-transmitting panel with diffusion slots on the top of the reaction panel, without affecting the flow of free radicals, the photocatalyst particles are effectively constrained from being detached from the groove under the action of vibration and airflow, ensuring the stability of the sample. At the same time, the light-transmitting panel has high optical transmittance, ensuring that the light penetrates uniformly and excites the surface of the particles to generate free radicals. The stability, representativeness and accuracy of the detection are effectively improved.

[0024] 2. The present application uses the circumferentially distributed air duct to intermittently spray high-purity nitrogen gas to the pressure block at the edge of the reaction panel, uses the chamfer structure to optimize airflow guidance, generates a stable downward driving force, and combines with the elastic connecting piece to realize uniform and stable reciprocating vibration of the reaction panel, effectively preventing eccentric load and jamming. Vibration promotes the turnover of photocatalyst particles, improving the uniformity of light.

[0025] Meanwhile, the horizontally sprayed nitrogen gas forms a symmetrical centripetal airflow in the cavity, causing free radicals to converge towards the center, and cooperating with the bottom negative pressure suction to build an efficient transmission field with centripetal convergence at the top and vertical suction at the bottom. The inert nature of nitrogen gas drives vibration while avoiding free radical quenching, ensuring a clean reaction environment, achieving high integration of vibration excitation, free radical directional transport and chemical fidelity, and improving detection sensitivity and accuracy.

[0026] 3. The present application realizes precise selection and regulation of the wavelength band of incident light through the light filter panel, ensures the excitation of photocatalysts under specific light conditions, avoids stray light interference, and improves the controllability and accuracy of the reaction.

[0027] Meanwhile, the telescopic mesh cover set between the light filter panel and the reaction panel effectively intercepts fine particulate matter that may be raised during vibration, preventing particles from entering the downstream free radical detection module and causing pollution. It not only ensures the smooth flow of free radicals, but also realizes the interception of particles in motion, improving the stability and reliability of the detection. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a perspective structural schematic diagram of a photocatalyst surface photogenerated free radical detection device of the present application.

[0029] Figure 2 is a perspective structural exploded schematic diagram of a photocatalyst surface photogenerated free radical detection device of the present application.

[0030] Figure 3 is a partial perspective structural sectional view of a photocatalyst surface photogenerated free radical detection device of the present application.

[0031] Figure 4 is a planar sectional view of a photocatalyst surface photogenerated radical detection device of the present application.

[0032] Figure 5 is a three-dimensional structural sectional view of an intermediate section of a photocatalyst surface photogenerated radical detection device of the present application.

[0033] Figure 6 is a three-dimensional structural schematic diagram of a reaction panel and a light-transmitting panel of a photocatalyst surface photogenerated radical detection device of the present application.

[0034] Figure 7 is a three-dimensional structural sectional view of an air passage of a photocatalyst surface photogenerated radical detection device of the present application.

[0035] Figure 8 is an enlarged schematic diagram of A of the photocatalyst surface photogenerated radical detection device of the present application. Figure 5

[0036] Figure 9 is an enlarged schematic diagram of B of the photocatalyst surface photogenerated radical detection device of the present application. Figure 5

[0037] Figure 10 is an enlarged schematic diagram of C of the photocatalyst surface photogenerated radical detection device of the present application. Figure 5

[0038] In the figure, the reference numerals are: 1, reactor main body; 11, reaction cavity; 12, light-filtering panel; 121, upper fixed part; 122, lower fixed part; 2, reaction panel; 21, recess; 211, light-transmitting panel; 212, diffusion slot; 22, through hole; 3, elastic connecting piece; 31, compression spring; 311, sleeve; 312, ring sleeve; 32, sealing washer; 4, vibration generator; 41, air passage; 42, pressure-receiving block; 421, chamfer structure; 5, negative pressure nozzle; 6, telescopic mesh cover; 61, upper buckle; 62, lower buckle. DETAILED DESCRIPTION

[0039] In order to further understand the features, technical means and achieved specific purposes and functions of the present application, the present application is described in further detail below in combination with the drawings and specific embodiments.

[0040] Reference is made to Figures 1-5 ​​​As shown, a kind of photocatalyst surface photogenerated radical detection device, including reactor main body 1, the light source module is provided in the upper of reactor main body 1, and the radical detection module is provided in the lower, the reactor main body 1 inside is equipped with the reaction cavity 11 being communicated with the radical detection module, the reaction cavity 11 is equipped with reaction panel 2, the reaction panel 2 is opened with the recess 21 for placing photocatalyst particulate, reaction panel 2 center is opened with the through-hole 22 for the radical downward flow in the light direction, reaction panel 2 can be vibrated up and down along the light direction, reactor main body 1 has the step surface, the step surface is left with the movable gap between reaction panel 2, the step surface is equipped with the elastic connecting piece 3 between reaction panel 2 bottom surface, reactor main body 1 is equipped with the vibration generator 4 for driving reaction panel 2 periodic vibration, under the start state of vibration generator 4, reaction panel 2 is driven gradually downward movement by driving force, while elastic connecting piece 3 is in the compression energy storage state, under the intermittent stop state of vibration generator 4, elastic connecting piece 3 drives reaction panel 2 gradually rebounds, forms reciprocating vibration, the bottom of reactor main body 1 is equipped with the negative pressure nozzle 5 for introducing radical from reaction cavity 11 into radical detection module.

[0041] The light source module and radical detection module are not shown in the figure.

[0042] When photocatalyst surface photogenerated radical detection is carried out, first, the photocatalyst particulate to be measured is uniformly placed in the recess 21 of the reaction panel 2, to ensure that the particulate is in the core light irradiation area of the reaction cavity 11. Subsequently, the light source module is started, and the light beam emitted thereby is vertically irradiated into the reaction cavity 11. The photocatalyst particles are excited to generate radicals with high reactivity under the action of light, and the radicals exist in gaseous form on the surface of the particles and in the surrounding space thereof.

[0043] At the same time, the vibration generator 4 provided on the reactor main body 1 is started, and periodically outputs driving force in operation, which acts on the edge of the reaction panel 2 to make the reaction panel 2 receive a downward thrust in the vertical direction. In the stage of continuous operation of the vibration generator 4, the reaction panel 2 moves gradually downward along the light direction under the action of the driving force, overcoming the elastic force of the elastic connecting piece 3. At this time, the elastic connecting piece 3 provided between the step surface and the bottom surface of the reaction panel 2 is compressed, stores elastic potential energy, and forms an energy storage state.

[0044] When the vibration generator 4 enters the intermittent stop operation stage, the external driving force disappears, and at this time, the elastic connecting piece 3 begins to release the elastic potential energy stored previously. The upward elastic force generated by the recovery deformation of the elastic connecting piece 3 acts on the reaction panel 2, drives it to gradually rebound upward from the lowest position, and restores to the initial or nearly initial position.

[0045] Through the periodic start and stop of the vibration generator 4, the reaction panel 2 realizes continuous and stable reciprocating vibration under the cooperation of the elastic connecting piece 3. The reciprocating vibration of the reaction panel 2 drives the photocatalyst particles in the groove 21 to have a micro displacement, rolling or slight overturning, breaks the shielding formed between the particles due to gravity accumulation, and makes the originally lower layer and shielded particle surface have the opportunity to be exposed to light, thereby improving the uniformity of the overall light and the sufficiency of the photocatalytic reaction, and truly reflecting the overall activity level of the photocatalyst.

[0046] While the reaction panel 2 is continuously vibrating, the negative pressure nozzle 5 at the bottom of the reactor body 1 is continuously working, connected to a vacuum air pump, and forms a negative pressure airflow field in the reaction cavity 11 from top to bottom along the axis direction of the through hole 22. The negative pressure environment promotes the free radicals generated by the reaction to flow downward from the space above the reaction panel 2 through the central through hole 22 and be directed to the free radical detection module below. Since the through hole 22 is located at the center of the reaction panel 2, the negative pressure suction effect forms a gas flow confluence area centered on the through hole 22 in the reaction cavity 11, and the free radicals gradually converge from the periphery to the central area under the guidance of the airflow and enter the detection channel through the through hole 22.

[0047] Finally, the continuously generated free radicals on the surface of the photocatalyst are efficiently and stably transported to the free radical detection module through the through hole 22 under the action of negative pressure suction, providing a high-quality airflow sample for subsequent laser excitation and fluorescence signal collection, thereby realizing high-sensitivity and high-representative quantitative detection of photo-generated free radicals.

[0048] Referring to Figures 2-7 As shown, the top of the reaction panel 2 is fixedly provided with a light-transmitting panel 211 for preventing particulate matter from separating from the groove 21, and a plurality of diffusion grooves 212 for free radical flow are formed on the surface of the light-transmitting panel 211.

[0049] When detection is performed, the fixed light-transmitting panel 211 at the top of the reaction panel 2 plays a limiting and protective role, covers the groove 21, can effectively constrain the photocatalyst particulate matter, prevent it from separating from the groove 21 during subsequent vibration or airflow disturbance, and ensure that the sample remains stable during the entire detection process.

[0050] At the same time, the light-transmitting panel 211 is made of a material having high transmittance to the detection light wave band, allowing the light emitted by the light source module to fully penetrate and uniformly irradiate the surface of the particulate matter, ensuring the normal progress of the photocatalytic reaction. The diffusion grooves 212 formed on the surface of the light-transmitting panel 211 serve as gas transmission channels, allowing the free radicals generated by the photocatalytic reaction on the surface of the particulate matter to escape and enter the space above the reaction panel 2, and then participate in the subsequent downward transport process. The effective fixation of the particulate matter and the efficient release of the free radicals are balanced, thereby ensuring the stability and accuracy of the detection signal.

[0051] Referring to Figures 3-8 As shown, the vibration generator 4 includes a gas passage 41 opened on the reactor body 1 and communicated with the reaction cavity 11, and a pressure block 42 arranged opposite to the gas passage 41, the reactor body 1 is circumferentially uniformly distributed with a plurality of gas passages 41, and the reaction panel 2 is fixed with a pressure block 42 corresponding to each gas passage 41, and the side of the pressure block 42 facing the gas passage 41 is provided with a chamfer structure 421.

[0052] When the vibration generator 4 works, the compressed gas is intermittently sprayed into the reaction cavity 11 through the multiple gas passages 41 uniformly distributed circumferentially on the reactor body 1, and the high-speed airflow directly impacts the surface of the pressure block 42 after being sprayed out of the gas passage 41, generating a downward force. The chamfer structure 421 on the side of the pressure block 42 facing the gas passage 41 effectively guides the airflow direction, so that the pressure block 42 is subjected to the downward thrust of the airflow along the inclined surface.

[0053] With the synchronization of the air passage of each gas passage 41, multiple pressure blocks 42 are simultaneously subjected to force, so that the reaction panel 2 is uniformly stressed, avoiding partial load or jamming, thereby realizing smooth and coordinated reciprocating motion up and down under the periodic airflow excitation, and combining the elastic connecting piece 3 to complete the continuous vibration disturbance of the photocatalyst particles.

[0054] Referring to Figures 4-8 As shown, the air passage direction of each gas passage 41 is perpendicular to the axis direction of the through hole 22, and when the gas passage 41 is ventilated to act on the pressure block 42, the free radicals gradually converge to the central area under the action of the airflow, and cooperate with the negative pressure nozzle 5 to form a synergistic airflow field with upward centripetal convergence and downward vertical suction.

[0055] When the gas passage 41 is ventilated, the airflow is sprayed horizontally along the direction perpendicular to the axis of the through hole 22, and acts on the pressure block 42 at the edge of the reaction panel 2 to drive vibration, and the horizontal airflow is sprayed inward after entering the reaction cavity 11. Since the gas passages 41 are uniformly distributed circumferentially along the reactor body 1, the horizontal airflow in each direction acts symmetrically and cancels out the lateral momentum, forming a trend of converging to the central axis in the reaction cavity 11, and promoting the free radicals generated above the reaction panel 2 to gradually gather from the periphery to the central area along the airflow.

[0056] At the same time, the convergence effect is coupled with the vertically downward suction airflow generated by the negative pressure nozzle 5 located at the bottom of the reactor, and the upward centripetal convergence flow and the downward axial suction flow continuously connect at the inlet of the through hole 22, thereby constructing a synergistic airflow field with upward centripetal convergence and downward vertical suction, effectively improving the transmission efficiency of free radicals from the reaction zone to the detection channel, reducing diffusion loss, and ensuring detection sensitivity.

[0057] Referring to Figures 4-8 As shown, the airflow of each gas passage 41 is nitrogen.

[0058] When the airway 41 is ventilated, the inhaled gas is high-purity nitrogen. As an inert gas, nitrogen can effectively transfer momentum to the stressed block 42 to drive the reaction panel 2 to vibrate after entering the reaction cavity 11, and will not chemically react or quench with active free radicals generated in the photocatalytic reaction process.

[0059] The chemical stability of nitrogen ensures that the original concentration of free radicals and the reaction environment in the reaction cavity 11 are not disturbed by the carrier gas, avoiding side reactions or background signal fluctuations caused by the introduction of active gases such as oxygen or water vapor. At the same time, the continuous flow of nitrogen helps to maintain a clean gas phase environment in the reaction cavity 11, inhibits the accumulation of pollutants, improves the accuracy and repeatability of detection, and ensures the chemical fidelity of the free radical generation and transmission process.

[0060] Referring to Figures 3-5 As shown, the elastic connecting piece 3 includes a compression spring 31, and a sleeve 311 vertically extends downward on the inner side of the reaction panel 2. A ring 312 is fixedly arranged on the reactor body 1 and sleeved on the sleeve 311. The compression spring 31 is sleeved on the sleeve 311 and located between the reaction panel 2 and the ring 312, and the two ends of the compression spring 31 are fixedly connected with the reaction panel 2 and the ring 312 respectively.

[0061] When the vibration generator 4 drives the reaction panel 2 to move downward, the sleeve 311 vertically extending downward on the inner side of the reaction panel 2 moves synchronously, the ring 312 sleeved on the sleeve 311 remains stationary on the reactor body 1, and the compression spring 31 located between the reaction panel 2 and the ring 312 is gradually compressed during the relative movement of the two, storing elastic potential energy.

[0062] With the intermittent stop of the vibration generator 4, the external driving force disappears, and the compression spring 31 begins to release the energy stored, and the elastic force generated by the recovery deformation acts on the reaction panel 2 and the ring 312 fixedly connected therewith, pushing the reaction panel 2 to rebound upward and realizing the reset movement, so as to realize the reciprocating vibration of the reaction panel 2.

[0063] Referring to Figures 3-5 As shown, the elastic connecting piece 3 further includes a sealing gasket 32, which is coaxially arranged with the sleeve 311. The upper and lower end faces of the sealing gasket 32 are tightly attached to the reaction panel 2 and the stepped surface respectively. When the reaction panel 2 moves downward, the sealing gasket 32 is in a self-adaptive compression deformation state.

[0064] When the reaction panel 2 moves downward during the vibration process, the sealing washer 32 coaxially arranged with the sleeve 311 is compressed due to the decreasing distance between the reaction panel 2 and the step surface, and the upper and lower end surfaces thereof always keep close contact with the bottom surface of the reaction panel 2 and the step surface, and the adaptive elastic deformation occurs during the compression process, effectively filling the movable gap between the reaction panel 2 and the reactor body 1.

[0065] In the dynamic compression state, the sealing performance is still good, preventing the gas in the reaction cavity 11 from leaking around the sleeve 311, ensuring the stability of the negative pressure suction gas flow and the integrity of the free radical transmission path.

[0066] Referring to Figures 1-5 As shown, the top of the reactor body 1 is provided with a light filtering panel 12.

[0067] When detection is performed, the light filtering panel 12 provided at the top of the reactor body 1 allows the light beam emitted by the light source module to selectively pass through and irradiate into the reaction cavity 11, and the light filtering panel 12 integrates an optical filter of a specific wavelength according to the detection requirement, which can filter out the unwanted spectral components and only allow the light of the target waveband to pass through, thereby accurately controlling the light irradiation conditions on the surface of the photocatalyst.

[0068] By replacing the light filtering element of the light filtering panel 12, the targeted excitation of catalysts with different light response ranges can be realized, the stray light interference can be avoided, and the photocatalytic reaction can be ensured to be stably performed in the set light irradiation environment, thereby providing controllable and adjustable optical excitation conditions for the generation of free radicals.

[0069] Referring to Figures 2-5 , Figure 9 and Figure 10 As shown, a telescopic mesh cover 6 is arranged between the light filtering panel 12 and the reaction panel 2 to prevent some small particulate matters from being carried by the gas flow, the light filtering panel 12 is provided with an upper fixing portion 121, the sleeve 311 is provided with a lower fixing portion 122, the telescopic mesh cover 6 is provided with an upper buckle 61 and a lower buckle 62 at the upper end and the lower end thereof respectively, and the upper fixing portion 121 and the lower fixing portion 122 are respectively provided with a clamping groove matched with the corresponding buckle.

[0070] When the reaction panel 2 reciprocates up and down during the vibration process, the telescopic mesh cover 6 between the light filtering panel 12 and the reaction panel 2 is synchronously stretched or compressed, which can effectively block the small particulate matters possibly raised in the groove 21 due to vibration, preventing them from entering the free radical detection module downward along the gas flow and causing pollution.

[0071] The upper buckle 61 of the telescopic screen cover 6 is quickly locked with the upper fixed part 121 clamping groove on the light filtering panel 12, and the lower buckle 62 is firmly connected with the lower fixed part 122 clamping groove on the sleeve 311, so that the telescopic screen cover 6 is stably installed in dynamic motion and cannot fall off or deviate. During the movement of the reaction panel 2, the telescopic screen cover 6 is deformed by its elasticity to adapt to the change of the distance between the upper and lower parts, so that the free flow of free radicals is maintained, and the effective interception of particulate matter is realized.

[0072] A method for detecting photo-generated radicals on the surface of a photocatalyst, applied to the photocatalyst surface photo-generated radical detection device described above, comprising the following steps:

[0073] S1, the photocatalyst particles are placed in the groove 21 of the reaction panel 2, the light-transmitting panel 211 is covered, and the light source module is started to irradiate, so that free radicals are generated on the surface of the particles;

[0074] S2, the reaction panel 2 is driven to reciprocate up and down by periodically starting and stopping the vibration generator 4, so that the particles are turned over to be fully exposed to light;

[0075] S3, nitrogen is introduced into the airway 41 to impact the pressure block 42, and the reaction panel 2 is vibrated, and the negative pressure nozzle 5 is used to form a synergistic airflow field of centripetal convergence and vertical suction in the reaction cavity 11;

[0076] S4, the free radicals are transported downward to the free radical detection module through the through hole 22, the fluorescence is excited by laser, and the signal is detected to realize quantitative analysis.

[0077] The present application promotes the dynamic overturning of the photocatalyst particles by the reciprocating vibration of the reaction panel 2 and the cooperation of the top light-transmitting panel 211, breaks the accumulation and shielding, fully exposes the deep surface to light, effectively restrains the particles from falling off by the light-transmitting panel 211, and guarantees the penetration of light and the escape of free radicals, improves the reaction uniformity and detection representativeness.

[0078] The nitrogen is sprayed through the circumferential airway 41 to drive the vibration, the chamfer structure 421 is stressed, and the reaction panel 2 is stably reciprocated. With the nitrogen being sprayed to the center, the horizontal airflow forms a centripetal convergence field, which is coupled with negative pressure suction to build an efficient transmission channel, and the free radical collection efficiency is improved. At the same time, the telescopic screen cover 6 effectively intercepts particulate matter in dynamic vibration, prevents pollution, and guarantees the flow of free radicals, realizes the uniformity of light, the stability of particles, the efficiency of transmission and the reliability of detection.

[0079] The above embodiments only express one or several embodiments of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the protection scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A photocatalyst surface photogenerated free radical detection device, comprising a reactor body, a light source module located directly above the reactor body, a free radical detection module located directly below the reactor body, and a reaction chamber connected to the free radical detection module inside the reactor body; Its features are, The reaction chamber is provided with a reaction panel, and the reaction panel has grooves for placing photocatalyst particles. The reaction panel has a through hole in the center along the light direction to allow free radicals to flow downwards, and the reaction panel can vibrate up and down along the light direction. The reactor body has a stepped surface, with a movable gap between the stepped surface and the reaction panel, and an elastic connector is provided between the stepped surface and the bottom surface of the reaction panel; The reactor body is equipped with a vibration generator to drive the reaction panel to vibrate periodically; When the vibration generator is running, the reaction panel moves downward under the driving force, while the elastic connector is in a compressed and energy-storing state. When the vibration generator is intermittently stopped, the elastic connector drives the reaction panel to gradually rebound, forming reciprocating vibration. The bottom of the reactor body is equipped with a negative pressure nozzle for introducing free radicals from the reaction chamber into the free radical detection module; A light-transmitting panel is fixed to the top of the reaction panel to prevent particles from falling out of the groove. The surface of the light-transmitting panel has several diffusion slots for free radicals to flow through. The vibration generator includes an air passage opened on the reactor body and connected to the reaction chamber, and a pressure block set opposite the air passage. Several air passages are evenly distributed around the reactor body. A pressure block is fixedly provided on the edge of the reaction panel corresponding to each air passage. The side of the pressure block facing the air passage has a chamfered structure. The ventilation direction of each airway is perpendicular to the axis of the through hole. When the airway vents onto the pressure block, free radicals gradually converge toward the central area under the action of the airflow, and work together with the negative pressure nozzle to form a synergistic airflow field with centripetal convergence at the top and vertical suction at the bottom.

2. The photocatalyst surface photogenerated free radical detection device according to claim 1, characterized in that, Each airway carries nitrogen gas.

3. The photocatalyst surface photogenerated free radical detection device according to claim 1, characterized in that, The elastic connector includes a compression spring, a sleeve extending vertically downward from the inside of the reaction panel, a ring sleeve fixed on the reactor body and fitted onto the sleeve, the compression spring being fitted onto the sleeve and located between the reaction panel and the ring sleeve, and both ends of the compression spring being fixedly connected to the reaction panel and the ring sleeve respectively.

4. The photocatalyst surface photogenerated free radical detection device according to claim 3, characterized in that, The elastic connector also includes a sealing gasket, which is coaxially arranged with the sleeve. The upper and lower end faces of the sealing gasket are tightly fitted with the reaction panel and the step surface, respectively. When the reaction panel moves downward, the sealing gasket is in an adaptive compression deformation state.

5. The photocatalyst surface photogenerated free radical detection device according to claim 3, characterized in that, A filter panel is installed on the top of the reactor body.

6. The photocatalyst surface photogenerated free radical detection device according to claim 5, characterized in that, A telescopic mesh cover is provided between the filter panel and the reaction panel to prevent some fine particles from being carried by the airflow. The filter panel has an upper fixing part, and the sleeve has a lower fixing part. The upper and lower ends of the telescopic mesh cover are respectively provided with upper and lower buckles. The upper and lower fixing parts are respectively provided with slots that engage with the corresponding buckles.

7. A method for detecting photogenerated free radicals on the surface of a photocatalyst, applied to the photogenerated free radical detection device described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Place the photocatalyst particles into the groove of the reaction panel, cover the light-transmitting panel and turn on the light source module to irradiate and stimulate the generation of free radicals on the particle surface. S2. By periodically starting and stopping the vibration generator, the reaction panel is driven to vibrate up and down, so that the particles are turned over to be fully exposed to light. S3. Nitrogen gas is introduced into the gas channel to impact the pressure block, causing the reaction panel to vibrate. At the same time, the negative pressure nozzle is used to form a synergistic airflow field of centripetal convergence and vertical suction in the reaction chamber. S4. Free radicals are transported downwards through the through-hole to the free radical detection module by airflow. The fluorescence is excited by laser and the signal is detected to achieve quantitative analysis.

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