Photonic crystal fiber chemical system

Abstract

The invention discloses a photonic crystal optical fiber chemical system, and relates to the technical field of optical fiber chemistry, photocatalysis, electrocatalysis and multifunctional membrane electrodes. According to the system, a three-layer membrane electrode structure of an anode catalyst layer, a proton or ion exchange layer and a cathode catalyst layer is constructed by taking a photonic crystal fiber with a periodic microstructure as a light guide and support framework. A functional liquid with an adjustable refractive index and nonlinear response capability is introduced into an optical fiber pore channel, so that accurate regulation and control on a light propagation path, mode field distribution and light intensity are realized, and frequency doubling excitation and high-energy photon generation are supported. The system can be used for photocatalysis, electrocatalysis and photoelectric synergistic reaction at the same time, has an in-situ trace detection function, and is suitable for the fields of green energy conversion, environment monitoring, multi-mode optical fiber analysis and the like. The device has the advantages of high structure integration level, high light energy utilization rate, accurate interface control, high reaction efficiency and the like.

Description

I. TECHNICAL FIELD

[0001] The present application relates to the technical field of optical fiber chemistry, photonic crystal optics and multifunctional catalytic materials, in particular to a multimodal optical fiber chemical system based on a photonic crystal fiber structure, especially an integrated membrane electrode platform for photocatalysis, electrocatalysis, photoelectric synergistic catalysis, trace detection and in-situ analysis, belonging to the advanced functional materials, optoelectronic devices and green chemistry cross-fusion frontier technology category.

[0002] Key words: optical fiber chemistry, photonic crystal fiber, optical fiber chemistry membrane electrode, photocatalysis, electrocatalysis, photoelectrocatalysis, multi-catalytic synergy, photoelectric synergistic catalysis, multi-layer interface chemistry II. BACKGROUND

[0003] Photonic crystal fiber (PCF) is a kind of special optical fiber that realizes light guiding regulation through microstructure periodic design. Its typical structural feature is that the cladding region is arranged with a regular array of air holes, and the key optical properties of the optical fiber such as dispersion, nonlinearity and mode field distribution can be precisely regulated by adjusting the hole diameter, arrangement period and geometric shape. Since the 1990s, PCF has attracted wide attention in the fields of supercontinuum generation, nonlinear optics and precision sensing.

[0004] In the early technology, Russell et al. first systematically described the basic structure and light guiding principle of PCF in US Patent 6,477,232B1 in 2002, and proposed that by introducing a periodic air hole structure into a quartz substrate, a photonic band gap can be formed to realize selective regulation of the light guiding region. Knight et al. further pointed out in US Patent 6,131,415 in 2000 that a hexagonal symmetric air hole layout has advantages in optimizing dispersion characteristics and mode field distribution, which can significantly enhance the nonlinear response of the optical fiber.

[0005] In terms of manufacturing technology, Takahashi et al. proposed a method for assembling and maintaining the integrity of the hole structure in US Patent 7,360,802B2, which realized the manufacturing of high uniformity and low loss PCF; Kato et al. further refined the doping method and multi-hole material matching strategy in US Patent 7,620,229B2, which provided a basis for subsequent functional material integration.

[0006] Although the prior art has systematic results in the design of optical fiber structure and light guiding performance, there is still a lack of integrated and functional design in the application of PCF to chemical reaction platform, especially to photocatalysis and micro-reaction system. For example, there is no PCF system with stable structure, good material compatibility, and suitable for reaction mass transfer-light guiding coupling, and there is no patent to clearly propose how to introduce functional photocatalytic materials (such as TiO2, metal nanoparticles, etc.) into the air hole or inner wall of PCF, and realize in-situ reaction or spectral monitoring combined with laser introduction. Therefore, it is urgent to develop an integrated optical fiber platform with "light guiding-catalysis-sensing" functions to expand the application boundary of photonic crystal fiber in the field of chemical reaction and detection. III. SUMMARY

[0007] 3.1 Problems to be solved

[0008] The existing photocatalysis, electrocatalysis or photoelectrocatalysis system generally has the following technical bottlenecks:

[0009] 1. Low reaction efficiency and low energy utilization rate: the traditional catalytic platform relies on macrostructure, has poor energy concentration ability, and has low coupling efficiency of reactants and excitation light or electricity;

[0010] 2. Insufficient interface control precision: the existing electrode or catalytic structure is mostly two-dimensional coating, and lacks three-dimensional spatial precision control means for the catalytic reaction interface, ion channel and light propagation path;

[0011] 3. Low structure integration and dispersed functions: the functions of catalysis, sensing, light guiding and detection are usually distributed in different devices, and it is difficult to realize reaction-analysis integration;

[0012] 4. No dynamic response and adjustable control ability: most of the photocatalytic systems have fixed structure, and cannot realize light field modulation and reaction self-regulation according to external conditions (such as light intensity and reactant concentration);

[0013] 5. Not suitable for micro-scale reaction system: the traditional reactor has large volume and slow response, and is not suitable for emerging fields such as microfluidic, chip-level catalytic device and in-situ monitoring.

[0014] The present application provides an optical fiber chemical system based on photonic crystal fiber, which realizes efficient energy coupling, reaction interface precision control, in-situ detection of reaction process and miniaturized module integration by introducing adjustable structure parameters (such as air hole duty cycle), injecting functional liquid (with refractive index regulation and nonlinear frequency doubling ability), combining membrane electrode structure design (photocatalysis, electrocatalysis and photoelectric synergistic catalysis), and multi-dimensional photonic crystal arrangement and multi-core structure.

[0015] The application solves the key problems of the optical fiber chemical system, such as difficulty in integration of light guiding-catalysis-sensing, low precision of light field regulation and reaction control, and difficulty in realizing multi-mode reaction cooperation, and is widely applicable to the fields of energy catalysis, environmental detection, biochemical analysis, etc. 3.2 Summary of the application

[0017] The application aims to provide a photonic crystal fiber chemical system to solve the problem that the traditional optical fiber cannot effectively realize photocatalysis, electrocatalysis and photoelectric cooperative catalysis reaction, and to improve the integration, selectivity and energy utilization efficiency of light-controlled chemical reaction.

[0018] The core of the application is to use a photonic crystal fiber (PCF) with a periodic microstructure cladding as a light guiding and structural support platform, and to construct it as the main skeleton of the fiber chemical membrane electrode. The liquid with optical response capability is injected or flowed in the pores of the photonic crystal fiber, and the liquid has adjustable refractive index and nonlinear optical response capability, which can dynamically adjust the propagation path, scattering angle, scattering intensity and mode field distribution of light in the fiber, and then regulate the photocatalysis, electrocatalysis and photoelectrocatalysis reaction in the excitation region.

[0019] The system cooperates the fine light regulation structure inside the optical fiber and the functional structure of the membrane electrode to construct an integrated optical fiber chemical device with multi-catalytic mechanism cooperation and multi-interface reaction control capability. Among them, the anode and cathode optical fiber catalytic layers are mirror-symmetrically arranged in structure and function, which can support reversible reaction and photo-thermal coupled catalytic process, and are suitable for constructing a bidirectional reaction platform and a responsive sensor device.

[0020] Compared with the prior art, the photonic crystal fiber chemical system proposed by the application has the following advantages:

[0021] The optical fiber as the main skeleton of the membrane electrode realizes the integration of light guiding, catalysis and ion exchange functions;

[0022] The dynamic refractive index and nonlinear effect of the liquid medium enhance the light control sensitivity and reaction adjustability;

[0023] The multi-catalytic mechanism (light, heat, and electricity) cooperation greatly improves the reaction conversion rate and selectivity;

[0024] The reversible structure and symmetric catalytic layer design are suitable for bidirectional catalysis, closed-loop regulation and programmable reaction system;

[0025] Supporting microreactor integration, trace detection and multi-field applications such as environment, energy and biochemistry.

[0026] The present invention provides a photonic crystal fiber chemical platform with high functional density and high space utilization, expanding the application boundaries of optical fiber technology in energy conversion, environmental monitoring, microfluidic catalysis and other aspects.

[0027] The present invention further proposes a three-layer fiber-optic chemical membrane electrode design for achieving efficient photothermal and electrocatalytic multimode synergistic catalysis. The fiber-optic chemical membrane electrode comprises an anode fiber-optic catalytic layer, a proton or ion exchange layer, and a cathode fiber-optic catalytic layer. The layers work together to create a complete catalytic reaction microenvironment.

[0028] The anode and cathode fiber catalytic layers are symmetrical in structure and function, both using photonic crystal fiber as the basic framework to construct the following composite functional units:

[0029] Photonic crystal fiber scattering surface: used to control the scattering angle and spatial distribution of the excitation light to achieve directional coupling of light energy;

[0030] Thermal catalyst particles: increase the rate of thermal-sensitive reactions and enhance the reaction temperature field;

[0031] Photocatalyst particles: generate electron-hole pairs under light conditions, driving the photocatalytic reaction;

[0032] Electrocatalyst particles: enable efficient electrochemical reactions at low potentials;

[0033] Double electric layer: Enhances the dual-channel transmission capability of electrons and ions;

[0034] Conductive layer: maintains the current continuity of the entire membrane electrode;

[0035] Air-permeable or liquid-permeable layer: Optimize the transport path and diffusion efficiency of reactants / products.

[0036] The middle layer is a proton or ion exchange layer, which uses highly selective conductive materials (such as PEM or AEM), which not only ensures the effective transfer of ions, but also plays a role in physically isolating the anode and cathode catalytic reactants to prevent cross interference.

[0037] This membrane electrode structure integrates optical control, thermal management, electrical conduction and material exchange capabilities into the same optical fiber system, improving the interfacial reaction efficiency, reaction stability and system modularity. It is suitable for various application scenarios such as microfluidic devices, catalytic chips and reversible reaction platforms.

[0038] Furthermore, the present invention introduces a liquid with a tunable refractive index into the photonic crystal fiber chemical system, giving the system the ability to finely and dynamically control the propagation behavior of light. The liquid is injected into the microstructured channels of the photonic crystal fiber, and its refractive index changes in real time, influenced by factors such as temperature, component concentration, and electric field.

[0039] This tunable refractive index enables precise control over the following optical behaviors:

[0040] · Adjustment of the guided-mode structure: By changing the refractive index, the effective guided-mode number and bandgap boundary in the photonic crystal fiber are changed, affecting the propagation characteristics of the guided light mode;

[0041] · Optimization of the mode field distribution: The adjustment of the refractive index distribution causes controllable changes in the shape, size, and position of the mode field, enhancing the overlap area of the light field and the catalyst or reactant;

[0042] · Control of the energy concentration area: By local refractive index regulation, light energy is directed to the key reaction area of the membrane electrode, achieving directional excitation;

[0043] · Dynamic optimization of transmission efficiency: effectively reducing mode leakage and coupling loss, improving overall photon utilization rate.

[0044] This design breaks through the limitations of fixed refractive index and limited control ability in traditional optical fibers, building an intelligent light-controlled chemical platform with real-time response capability, improving the light excitation accuracy and catalytic efficiency of the reaction process, and is particularly suitable for complex multi-step reactions and dynamic adjustment scenarios.

[0045] Further, to expand the spectral response capability of the optical fiber chemical system and achieve high-energy excitation paths, the invention introduces a functional liquid with nonlinear optical properties into the photonic crystal fiber. The liquid can generate frequency doubling effects under guided light excitation, including second harmonic generation (SHG), third harmonic generation (THG), etc.

[0046] The key advantages of this technical solution are:

[0047] · Frequency doubling integration in optical fiber: By filling the nonlinear liquid in the microstructure channels of the photonic crystal fiber, the guided light and frequency doubling work together without the need for additional external optical devices;

[0048] · High-energy light excitation: The generated new wavelength high-energy photons (such as ultraviolet, deep ultraviolet) can precisely act on the membrane electrode area, inducing reactants to undergo bond rupture, dissociation, or electron transition;

[0049] · Selective reaction control: The frequency doubling process can be adjusted according to the input laser wavelength, power, and liquid response characteristics to achieve spectral selective excitation of target reactants;

[0050] · Enhanced photon utilization efficiency: Achieving single light source input and multiple frequency output, improving overall photon utilization rate and reaction conversion efficiency.

[0051] The present application significantly enhances the nonlinear optical response capability of the system by integrating the liquid frequency-doubling mechanism into the photonic crystal fiber structure, enabling the photonic crystal fiber chemical system to trigger high-energy chemical reactions at the molecular level, and is suitable for efficient conversion of low-activity molecules such as CO2, N2, H2O, etc. that are difficult to excite.

[0052] Further, the present application adjusts the ratio (d / A) between the hole diameter (d) and the arrangement period (A) of the air hole in the photonic crystal fiber to achieve fine control of the light guiding performance of the fiber, thereby improving the performance of the system in light field control and catalytic reaction.

[0053] The adjustment mechanism of the duty cycle (d / A) has the following technical advantages:

[0054] Optimize the photonic bandgap structure: adjusting the ratio of hole diameter to period can effectively control the position and width of the photonic bandgap, thereby selectively blocking or enhancing the propagation of light at specific wavelengths;

[0055] Adjust the mode field size: the larger the d / A, the weaker the confinement of light in the core, which is beneficial to the expansion of the mode field and the enhancement of the interaction with the surrounding catalyst or liquid;

[0056] Influence the nonlinear threshold: by adjusting the mode field energy density distribution through the duty cycle, the starting power threshold of the nonlinear optical response can be controlled;

[0057] Improve the reaction accuracy: optimize the d / A parameter to precisely focus the excitation light on the membrane electrode catalytic area, improve the reaction area selectivity and light control resolution.

[0058] Therefore, the present application uses the adjustable d / A duty cycle as a structure tuning means to realize the coupling control of the fiber light guiding behavior, mode field characteristics and reaction active area spatial position, providing a structural design basis for high-efficiency and high-selectivity fiber chemical systems.

[0059] Further, to realize stronger spatial light control capability and precise regulation of the catalytic reaction area, the present application proposes to expand the photonic crystal structure from the traditional one-dimensional periodic structure to a two-dimensional or three-dimensional arrangement form.

[0060] One-dimensional photonic crystal structure: refers to the basic configuration of the fiber cross-section direction with a periodic air hole array, commonly seen in hexagonal or square hole diameter arrangement, with good single-mode transmission and photonic bandgap formation capability;

[0061] Two-dimensional photonic crystal structure: realizes complex topology such as multi-period, quasi-lattice or defect guidance in the cross-section, which helps to introduce localized modes, defect states and enhance local light field;

[0062] Three-dimensional photonic crystal structures: These structures achieve periodic control of the refractive index in both the longitudinal and transverse directions. These structures can be constructed using methods such as multi-layer stacking, laser direct writing, and 3D printing, enabling true three-dimensional omnidirectional light control.

[0063] By introducing a two-dimensional or three-dimensional photonic crystal structure, the present invention has the following technical advantages:

[0064] Improve the localization capability of the light field and the mode field compression effect, and enhance the energy coupling with the catalytic active center;

[0065] Construct complex multi-mode interference structures to support multi-band excitation and selective response;

[0066] Supports the realization of embedded functional units such as reflection cavity, defect cavity, and resonant cavity to improve system integration;

[0067] Achieve precise positioning excitation of the membrane electrode area, reducing energy loss and the probability of side reactions;

[0068] Expand the functional boundaries of photonic crystal fibers to adapt to multi-channel detection, multi-dimensional response and multi-mode control.

[0069] In summary, the present invention improves the spatial dimension of the photonic crystal structure, enhances the system's light control ability and multi-interface synergistic reaction performance, and provides a new structural support for building a highly integrated, high-precision, and programmable fiber-optic chemical platform.

[0070] Furthermore, in order to realize multi-channel parallel reaction, regional excitation control and integrated instrument analysis functions, the present invention proposes a photonic crystal fiber based on a multi-core structure design.

[0071] The multi-core photonic crystal fiber structure has the following key technical features:

[0072] Multi-channel light guidance: Multiple parallel or circularly arranged optical fiber cores are embedded in a single optical fiber, each core can independently transmit excitation light of different wavelengths or different pulse parameters;

[0073] Functionally differentiated configuration: Each optical core can be injected with different types of functional liquids or coated with different types of catalysts to achieve regional catalysis or differentiated response;

[0074] Controllable coupling / isolation: Structural coupling or optical isolation between optical cores enables energy sharing or independent operation.

[0075] Integrated signal acquisition channels: Some optical cores can be configured as detection paths to collect absorption, Raman or fluorescence signals during chemical reactions in real time;

[0076] Array structure design: supports star, honeycomb, and symmetrical arrangements, making it easy to connect to existing instrument interfaces.

[0077] The multi-core photonic crystal fiber technology has the following innovative advantages:

[0078] Realize partition excitation and detection, suitable for asynchronous reaction or dynamic control system;

[0079] Improve the spatial resolution of analysis, and can construct a spatial distributed reaction monitoring network;

[0080] Enhance the parallel reaction capacity, and accelerate the catalyst screening or mechanism exploration;

[0081] Support the modular instrument analysis platform, and facilitate integration with spectrometer, microreactor and the like;

[0082] Flexible application, suitable for trace detection, drug screening, biochemical analysis and the like.

[0083] Therefore, the present application provides an innovative solution for a high-throughput, controllable and high-integration fiber chemical analysis and reaction platform by constructing a multi-core photonic crystal structure in a single optical fiber.

[0084] Further, for low-activity reaction systems (such as CO2 reduction, N2 cracking, water splitting, etc.), the present application proposes that the photonic crystal fiber chemical system works in a power interval above the nonlinear threshold, combines high-intensity light field and nonlinear optical effect, and improves the energy density and reaction activity.

[0085] In this operation mode, the system has the following core mechanisms:

[0086] When the optical power exceeds the nonlinear response threshold, the frequency doubling, self-focusing, Kerr effect, Raman scattering and other nonlinear behaviors in the liquid or material medium are triggered;

[0087] Mode field compression and photon density enhancement: strong local field is formed in the optical fiber, which effectively improves the excitation power per unit area of the reaction interface;

[0088] Synergistic photocatalytic mechanism activation: high-frequency photons or hot electrons excited by nonlinear optical effect directly act on reactant molecules to induce bond rupture, dissociation or polarization;

[0089] Triggered reaction control: the system starts a specific catalytic reaction only when the power reaches the set threshold, realizing light-controlled threshold operation;

[0090] Non-thermal energy utilization path: avoid the side reactions and energy waste caused by traditional thermal drive, and improve the selectivity and efficiency of the system.

[0091] The innovative effects brought by the technical solution include:

[0092] Break through the efficiency limitations of traditional photocatalysis and achieve nonlinear interactive catalysis under high-power drive;

[0093] Realize high-energy molecular activation pathways, suitable for inert molecular transformation;

[0094] Build intelligent response systems suitable for time-varying excitation, threshold control, and spatial modulation;

[0095] Enhance system adaptability and functional integration, and provide strong support for portable and scenario-based micro-reaction systems.

[0096] In summary, the present invention significantly enhances the control capability of the photonic crystal fiber chemical system over high-energy reaction pathways by introducing a nonlinear threshold driving mechanism, thereby expanding its application potential in energy conversion, environmental remediation, and basic scientific research.

[0097] Furthermore, in order to achieve in-situ monitoring and trace-level analysis of optical fiber chemical processes, the present invention integrates a spectral analysis module into the photonic crystal optical fiber chemical system to construct an integrated feedback platform with dual functions of excitation and detection.

[0098] The integrated spectrum analysis module has the following technical features:

[0099] Absorption spectroscopy function: real-time monitoring of the absorption changes of reactants or products at specific wavelengths to determine the reaction degree and conversion efficiency;

[0100] Raman scattering: Analyze reaction intermediates, structural changes, or functional group characteristics based on molecular vibration patterns;

[0101] Fluorescence detection function: used to identify target molecules with fluorescent characteristics, or to monitor spontaneous or labeled fluorescence signals in reactions;

[0102] Signal enhancement: Combining surface-enhanced Raman scattering (SERS), cavity-enhanced spectroscopy (CERS), or mode field compression to improve sensitivity;

[0103] Multimodal signal acquisition: supports simultaneous acquisition of multiple spectral information to improve detection throughput and discrimination accuracy;

[0104] Distributed multi-core configuration: Combined with a multi-core photonic crystal fiber structure, signal acquisition paths are set in different channels to achieve spatial partitioning detection.

[0105] The system advantages brought by the module integration include:

[0106] Achieve in-situ, real-time monitoring: No need to disrupt the reaction environment or take samples, maintaining process integrity;

[0107] • Applicable to trace level detection: with detection capability of nanomolar or even picomolar level, suitable for scenes such as poison identification and biomarker analysis;

[0108] • Linkable with digital platform: spectral signals can be connected with external analysis system in real time to build feedback control closed loop;

[0109] • Enhancing system intelligent level: combining spectral response to realize automatic adjustment of light power, reaction time or liquid composition;

[0110] • Facilitating integration and miniaturization: small module size supports handheld device or chip system embedding.

[0111] Therefore, by embedding the multi-modal spectral analysis function into the photonic crystal fiber chemical system, the ability of trace detection, reaction monitoring and data feedback regulation is significantly improved, and a new solution is provided for the fields of environmental protection, medical diagnosis and intelligent manufacturing.

[0112] Further, to improve ion transmission efficiency and membrane electrode reaction zone isolation performance, the present application introduces a proton or anion exchange membrane as an intermediate layer in the photonic crystal fiber chemical system, constituting one of the core structural components of the membrane electrode.

[0113] The proton / ion exchange layer has the following functions and characteristics:

[0114] • Directional ion conduction: in electrochemical reaction, only specific types of ions (such as H + or OH – ) are allowed to migrate unidirectionally, ensuring ion circuit closure;

[0115] • Effective isolation of anode / cathode reactants: preventing reactant cross contamination or side reactions, improving reaction selectivity and efficiency;

[0116] • High chemical stability and mechanical strength: suitable for various acidic or alkaline reaction systems, maintaining structural integrity;

[0117] • Adjustable conduction flux: by controlling film thickness, functional group density and other parameters, fine ion flux adjustment is realized;

[0118] • Compatible with photonic crystal structure: can be directly coated or embedded in photonic crystal fiber array without affecting light guiding and catalytic functions.

[0119] Common film materials include:

[0120] • Proton exchange membrane (PEM): such as Nafion, SPEEK, etc., suitable for cation migration in acidic environment;

[0121] • Anion exchange membrane (AEM): such as Q-PAF, FAA-3, etc., suitable for anion transfer in alkaline systems;

[0122] The introduction of the ion exchange layer can bring the following system advantages:

[0123] • Improve electrocatalytic efficiency: optimize ion supply path, accelerate interface reaction rate;

[0124] • Enhance system stability: realize physical and chemical double isolation between anode and cathode;

[0125] • Support long-term continuous operation: avoid performance degradation caused by cross contamination;

[0126] • Expand the adaptability of the reaction system: support CO2 reduction, N2 conversion, water splitting and other complex systems;

[0127] • Enhance the replaceability and modular design of the membrane electrode module.

[0128] In summary, the proton / ion exchange layer described in the present application realizes high selective ion conduction function in the scale of optical fiber, and is an indispensable component for building high-performance optical fiber chemical membrane electrode system. It is suitable for various energy conversion, environmental management and micro-scale catalytic application scenarios.

[0129] 3.3 Beneficial effects

[0130] The present application proposes an optical fiber chemical system based on photonic crystal fiber, which integrates light guiding, light field regulation, catalytic reaction and in-situ detection, and has the following beneficial effects:

[0131] 1. Realize multi-catalyst synergy: by integrating photo-catalysis, electro-catalysis, thermal catalysis and other mechanisms inside the optical fiber, realize energy coupling and synergistic enhancement, improve reaction efficiency and selectivity;

[0132] 2. High-precision light field regulation: use the synergistic effect of photonic crystal structure and functional liquid to dynamically control the mode field distribution, light propagation path and photon density, realize accurate positioning and programmable excitation of reaction sites;

[0133] 3. Frequency doubling mechanism enhances reaction capacity: functional liquid has nonlinear optical properties, which can realize second or third order frequency doubling under high-power excitation, output high-energy photons to excite the cracking and activation of difficult reaction molecules;

[0134] 4. Integration of optical fiber chemical membrane electrode structure: design symmetrical anode and cathode optical fiber catalytic layers, combine ion exchange membrane to form a sandwich type membrane electrode, suitable for reversible reaction, bidirectional driving or cyclic catalysis;

[0135] 5. Modularization and miniaturization: small system volume, suitable for microreactors, integrated chips and portable chemical platforms, which can be widely used in energy conversion, environmental purification and life science fields;

[0136] 6. Support for in-situ and trace detection: integrated spectral analysis module, multi-modal detection such as absorption, Raman and fluorescence can be realized, with in-situ, dynamic and trace analysis capabilities, forming a closed-loop feedback control system;

[0137] 7. Strong scalability: by adjusting the dimensionality of photonic crystals (1D / 2D / 3D), multi-core structure, liquid refractive index and nonlinear characteristics, it can adapt to different reaction paths and operating conditions, and support function upgrade and expansion;

[0138] 8. Nonlinear excitation enhances low-activity molecule conversion: through excitation mode above the nonlinear threshold, the reaction conversion rate of low-activity molecules such as CO2 and N2 is improved, providing an efficient solution for clean energy paths.

[0139] In summary, the present application breaks through the technical limitations of traditional catalytic systems in energy utilization rate, spatial integration, reaction selectivity and in-situ monitoring, and has significant innovation and industrial application prospects.

[0140] 3.4 Analysis of creativity, novelty and industrial applicability

[0141] 3.4.1 Creativity analysis

[0142] The present application introduces photonic crystal fiber into optical fiber chemical system, and constructs an optical fiber chemical platform with light control ability, catalytic function and signal feedback integration, which has the following substantial technical progress:

[0143] · Innovatively use photonic crystal fiber as the main skeleton of optical fiber chemical membrane electrode, integrate photocatalysis, electrocatalysis and thermal catalysis mechanisms, and form a multi-catalytic integrated system;

[0144] · Use liquid refractive index control and nonlinear frequency doubling effect to break through the limitations of traditional light sources and realize dynamic light control and high-energy excitation;

[0145] · Construct a multi-core photonic crystal fiber structure suitable for partition reaction and in-situ multi-modal spectral analysis;

[0146] · Extend the photonic crystal structure from one dimension to two or three dimensions to achieve higher-dimensional light field control capability;

[0147] · The system operates in a power region above the nonlinear threshold, which can be used to excite low-activity molecules such as CO2 and N2, and expand the reaction boundary.

[0148] The above scheme provides a new technical path in photocatalysis, energy utilization, reaction selectivity and integration, and has significant creativity.

[0149] 3.4.2 Novelty analysis

[0150] The existing literature and patents have not disclosed or suggested the use of the following comprehensive technical means:

[0151] • Utilize the internal structure of the photonic crystal fiber to form a fiber chemical membrane electrode;

[0152] • Introduce a liquid with nonlinear frequency multiplication capability into the photonic crystal fiber channel to enhance the catalytic reaction;

[0153] • Build an integrated chemical device that integrates optical fiber light guiding, frequency multiplication, catalysis and signal detection;

[0154] • Use the d / A duty cycle to adjust the photonic bandgap and mode field characteristics to achieve precise positioning of the reaction zone;

[0155] • Design a multi-core structure to realize parallel coupling of optical function and reaction function.

[0156] Therefore, the technical scheme of the present application has obvious novelty and is not disclosed in the prior art.

[0157] 3.4.3 Industrial applicability analysis

[0158] The photonic crystal fiber chemical system described in the present application has a clear structure, mature materials and preparation process, and has the following industrial practical value:

[0159] • Batch production is suitable for emerging fields such as photocatalysis, photoelectrochemistry and microreaction chips;

[0160] • Can be integrated into existing optical fiber analysis instruments and reaction devices to enhance functional modules;

[0161] • The system has high stability, repeatability, long service life and low energy consumption characteristics;

[0162] • Suitable for environmental detection, biological identification, energy conversion and air pollution control in multiple industry directions.

[0163] In summary, the present application not only has outstanding creativity and novelty, but also has obvious industrial applicability, and can solve the technical problems of low integration, poor reaction efficiency and difficulty in monitoring of existing catalytic systems in practical applications. IV. DESCRIPTION OF DRAWINGS

[0164] Figure 1 The structure of the photonic crystal fiber chemical system described in the present application is shown in the figure, which shows the relationship between the liquid filling and the light propagation path in the photonic crystal fiber.

[0165] Figure 2 The three-layer structure of the optical fiber chemical membrane electrode is shown in the figure, including the functional distribution of the anode fiber catalytic layer, the proton / ion exchange layer, and the cathode fiber catalytic layer. V. DETAILED DESCRIPTION

[0166] The application will be further described below in conjunction with the drawings and examples, but those skilled in the art should understand that these examples are only used to illustrate the application and should not be construed as limiting the scope of protection of the application.

[0167] Example 1: Construction of a membrane electrode reaction system based on a photonic crystal fiber

[0168] As shown in Figure 1 and Figure 2 , a two-dimensional photonic crystal fiber with a hexagonal arrangement of air holes is selected as the basic skeleton structure. By capillary action or micro-pump, a liquid with light response capability (such as a refractive index adjustable styrene derivative or a liquid graphene precursor) is injected to form a dynamically regulated optical guided mode system.

[0169] A membrane electrode structure is constructed on the surface of the optical fiber, specifically including:

[0170] · Anode fiber catalytic layer: coating of a conductive composite coating containing Pt / C and TiO2 nanoparticles;

[0171] · Proton exchange layer: insertion of a piece of Nafion membrane for realizing proton conduction of the anode / cathode;

[0172] · Cathode fiber catalytic layer: use of g-C3N4 / RuO2 composite, and connection of a platinum mesh as an auxiliary electrode.

[0173] The excitation light is introduced into the photonic crystal fiber through a laser coupling device, and a photocatalytic reduction reaction (such as CO2→CO) is induced at the membrane electrode interface, and the infrared or Raman spectrum of the product can be synchronously collected.

[0174] Example 2: Multi-core photonic crystal fiber for trace analysis

[0175] A photonic crystal fiber with a seven-core structure is used, in which the central core is used for excitation light introduction, and the six peripheral cores are used for signal collection at different positions. A multi-channel membrane electrode structure is constructed in the middle of the optical fiber, and a liquid with different catalyst or reactant concentrations is injected.

[0176] When the input laser pulse (532 nm) is excited by the central core, multiple membrane electrode reaction zones are simultaneously started, and the spectral response of each reaction channel is synchronously recorded through the peripheral optical fiber cores, thereby realizing high-throughput detection and analysis of trace substances.

[0177] Example 3: Frequency doubling excitation for high-energy reaction path construction

[0178] A functional liquid with third-order nonlinear susceptibility (such as styryl liquid crystal material) is selected to be injected into the hole of the photonic crystal fiber, and a third harmonic output (343 nm) is generated under the input of high-power pulsed laser (1030 nm), which initiates the N2 dissociation reaction.

[0179] This embodiment shows that under the conditions of high-power input and nonlinear response, the system realizes the excitation of the path that is difficult to trigger in traditional reactions through spontaneous frequency doubling and catalytic synergy, and has good industrial prospects and catalytic efficiency advantages.

Claims

1. A photonic crystal fiber chemical system, characterized in that: It includes a photonic crystal fiber with a periodic microstructure cladding. The optical fiber constitutes the main skeleton structure of the optical fiber chemical membrane electrode. A liquid with optical response capability is injected or flowed into the channel of the optical fiber. Used to adjust the light propagation path, scattering angle, scattering intensity and nonlinear optical effect inside the optical fiber. The system is based on the optical fiber light guiding effect, which stimulates the membrane electrode area to produce photocatalytic, electrocatalytic or photoelectrocatalytic reactions. Constructing a fiber-optic chemical device with multi-catalytic synergy and multi-interface control, The optical fiber catalytic layers of the anode and cathode have structural and functional symmetry. Suitable for reversible reaction systems, photothermal coupled catalysis or bidirectional detection platforms.

2. The system according to claim 1, wherein: The optical fiber chemical film electrode consists of the following three-layer structure: Anode fiber catalytic layer, proton or ion exchange layer and cathode fiber catalytic layer, The anode and cathode catalyst layers both include: a photonic crystal fiber light scattering surface, thermal catalyst particles, photocatalyst particles, electrocatalyst particles, a double electric layer, a conductive layer and a gas or liquid permeable layer.

3. The system according to claim 1 or 2, characterized in that The liquid has an adjustable refractive index, By changing the refractive index of the liquid, the guided mode structure, mode field distribution and transmission characteristics in the photonic crystal fiber are adjusted. This can then regulate the light field enhancement behavior in the reaction area of ​​the membrane electrode.

4. The system according to any one of claims 1 to 3, characterized in that The liquid has second-order or third-order nonlinear optical properties, Frequency doubling effect can be achieved under light-guided excitation. The generated new wavelength light is used to stimulate the dissociation, excitation or selective conversion of reactants in the fiber optic chemical membrane electrode.

5. The system according to any one of claims 1 to 4, characterized in that The ratio of the aperture to the period of the air holes in the photonic crystal fiber structure is adjustable. Used to optimize the photonic band gap position, mode field size and nonlinear threshold.

6. The system according to any one of claims 1 to 5, characterized in that The photonic crystal structure is in a one-dimensional, two-dimensional or three-dimensional arrangement form, To improve the multi-dimensional light confinement capability and membrane electrode interface positioning accuracy.

7. The system according to any one of claims 1 to 6, characterized in that The optical fiber is a multi-core photonic crystal fiber structure, Each core can be used for regional light-controlled excitation, catalytic reaction or spectral analysis. Suitable for parallel instrument analysis during fiber optic chemical reactions.

8. The system according to any one of claims 1 to 7, characterized in that The system operates in a power range above the nonlinear threshold. The high-intensity light field induces nonlinear effects and synergistically enhances the photocatalytic reaction. Used to stimulate high-efficiency conversion reactions of low-activity molecules such as carbon dioxide and nitrogen.

9. The system according to any one of claims 1 to 8, characterized in that The system integrates a spectrum analysis module, Combined with the output signal of the membrane electrode, multimodal detection of trace substances such as absorption, Raman, and fluorescence can be achieved. Suitable for environmental monitoring, biorecognition and microreactor feedback control.

10. The system according to any one of claims 1 to 9, characterized in that The proton or ion exchange layer is a proton exchange membrane or anion exchange membrane with directional ion conductivity, which is used to ensure the selective transmission of ions between the anode and the cathode and the spatial separation of the reaction areas.

Images