Method and device for calculating Z-type heterojunction solar hydrogen production efficiency limit

Abstract

The invention provides a method and a device for calculating a Z-type heterojunction solar hydrogen production efficiency limit. The method comprises the following steps: reading a vacuum energy level difference and energy band data input by a user; if the vacuum energy level difference is not 0, inputting the vacuum energy level difference and the energy band data into a first solar hydrogen production efficiency limit formula for calculation; if the vacuum energy level difference is 0, inputting the energy band data into a second solar hydrogen production efficiency limit formula for calculation; obtaining a limit value of the solar hydrogen production efficiency of the Z-type heterojunction; accurate calculation of the solar hydrogen production efficiency limit is achieved by deducing a Z-type heterojunction solar hydrogen production efficiency limit formula and combining the vacuum energy level difference and energy band data input by a user; according to an existing solar hydrogen production efficiency formula, all data parameter combinations are traversed, the solar hydrogen production efficiency is automatically calculated, a map is automatically generated, and the map is compared with a limit value of the map and verified. The method provides a limit value reference, helps a user to identify a performance bottleneck and guides an optimization direction.

Description

Technical Field

[0001] The present invention relates to the field of solar energy hydrogen production (STH), and in particular to a method and a device for calculating the efficiency limit of Z-type heterojunction hydrogen production. Background Art

[0002] With the increase in global energy demand and the intensification of environmental problems, the development of clean and renewable energy is particularly important. As a clean energy source, the efficient use of solar energy has attracted much attention, especially in the field of photocatalytic water splitting to produce hydrogen, because it can directly convert solar energy into clean hydrogen energy, has the advantages of no pollution and high energy density, and has broad application prospects. The Z-type heterojunction structure has become a popular research direction for improving photocatalytic efficiency due to its unique interface electron transport characteristics and excellent photoelectric conversion performance. Although Z-type heterojunction photocatalytic materials have advantages in electron-hole separation and light absorption performance, there are still bottlenecks in photoelectric conversion efficiency and material stability. Therefore, the development of new and efficient Z-type heterojunction photocatalytic materials and in-depth analysis and optimization of their structure and performance are crucial to improving the efficiency of solar water splitting hydrogen production technology. Summary of the invention

[0003] The purpose of the above invention is to provide a method and device for calculating the efficiency limit value of Z-type heterojunction solar hydrogen production, so as to solve the problem that the existing technology cannot well calculate the efficiency limit value of Z-type heterojunction in the process of solar hydrogen production.

[0004] The present invention provides a method and device for calculating the efficiency limit value of Janus Z-type heterojunction solar hydrogen production, the method comprising:

[0005] Read the vacuum energy level difference data and energy band data of the Janus Z type input by the user;

[0006] Inputting the vacuum energy level difference data into the first solar hydrogen production efficiency limit formula for calculation, so as to obtain the solar hydrogen production efficiency limit value of the Janus Z type;

[0007] The solar hydrogen production efficiency limit formula is as follows:

[0008]

[0009] where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at Represents the photon energy The differential of E g is the energy band gap of the Janus Z-type heterojunction, and ΔΦ is the potential difference between the upper and lower surface energy levels.

[0010] Furthermore, the method comprises:

[0011] Obtaining physical property parameter data of the Janus Z-type heterojunction;

[0012] The solar hydrogen production efficiency limit values ​​of all the physical parameter data are calculated by the first solar hydrogen production efficiency limit formula, and all the solar hydrogen production efficiency limit values ​​are plotted into an efficiency analysis graph.

[0013] Furthermore, the calculation formula for the minimum energy of photons that can participate in the redox reaction is:

[0014]

[0015] E min =0.615eV (2)

[0016] Where, χ(H2) is the overpotential of hydrogen evolution reaction, χ(O2) is the overpotential of oxygen evolution reaction, E g is the larger band gap between the two monolayers, E min is the minimum energy of a photon.

[0017] The derivation process of the efficiency limit formula of solar hydrogen production is: if and only if the overpotential of hydrogen evolution reaction is equal to 0.2eV, and the overpotential of oxygen evolution reaction is equal to 0.6eV, when E = E g When the E g , when E g =0.615ev, the solar hydrogen production efficiency limit is the maximum value, so take E g =E min As the corresponding energy band gap, the efficiency limit formula of solar hydrogen production is obtained.

[0018] Furthermore, the minimum band gap formula corresponding to the limit value is:

[0019]

[0020] where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E min is the minimum energy value of the photon, and ΔΦ is the potential difference between the upper and lower surface energy levels.

[0021] Furthermore, a method and device for calculating the efficiency limit of a common Z-type heterojunction solar hydrogen production are provided, the method comprising:

[0022] Read the two single-layer band structure data of the Z-type heterojunction input by the user;

[0023] The solar hydrogen production efficiency limit values ​​of all the physical parameter data are calculated by the second solar hydrogen production efficiency limit formula, and all the solar hydrogen production efficiency limit values ​​are plotted into an efficiency analysis graph.

[0024] Furthermore, the physical property parameter data includes energy band structure parameters.

[0025] Furthermore, the energy band structure parameters include: a valence band maximum value and a conduction band minimum value.

[0026] Furthermore, the calculation formula for the minimum energy of photons that can participate in the redox reaction is:

[0027] E g1 ≈E g2 ≈0.615eV (1)

[0028] E g1 +E g2 ≥1.23eV (2)

[0029]

[0030] Among them, E g1 and E g2 The band gap E of the two monolayers is min is the minimum energy of the photon that can participate in the reaction, and eV represents electron volts.

[0031] Furthermore, the step of calculating the solar energy hydrogen production efficiency limit values ​​of all corresponding physical property parameter data by using the two solar energy hydrogen production efficiency limit formulas includes:

[0032] All physical property parameter data are distributed in multiple parameter spaces, the physical property parameter data in the multiple parameter spaces are sampled or discretized, and the corresponding solar hydrogen production efficiency value is calculated for each physical property parameter data.

[0033] Furthermore, the step of plotting all solar hydrogen production efficiency limit values ​​into an efficiency analysis graph includes: using Matplotlib library to plot the efficiency analysis graph.

[0034] Furthermore, the method further comprises:

[0035] Combined with the current solar hydrogen production efficiency of the Z-type heterojunction and the solar hydrogen production efficiency limit, specific methods and suggestions on how to change the physical parameters to improve the solar hydrogen production efficiency are generated.

[0036] The present invention also provides a device for calculating the efficiency limit of Z-type heterojunction solar hydrogen production, the device comprising:

[0037] A parameter reading unit, used to read the vacuum energy level difference and energy band data of the Z-type heterojunction input by the user to obtain the necessary parameters of the Z-type heterojunction;

[0038] The calculation unit is used to input the vacuum energy level difference data and the energy band data into the solar hydrogen production efficiency limit formula for calculation, and obtain the solar hydrogen production efficiency limit value of the Z-type heterojunction.

[0039] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: the present invention derives the solar hydrogen production efficiency limit formula of the Z-type heterojunction, combines the vacuum energy level difference and energy band data input by the user, realizes high-precision and reliable calculation, and draws efficiency analysis maps by traversing multiple physical parameter data, provides comprehensive performance analysis and optimization suggestions, simplifies the user operation process, improves analysis efficiency, and significantly improves the scientificity, practicality and user experience of solar hydrogen production efficiency evaluation and optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a method for calculating the efficiency limit value of Z-type heterojunction solar hydrogen production provided by an embodiment of the present invention;

[0041] Figure 2 It is a calculation flow chart of the efficiency analysis map of the present invention;

[0042] Figure 3 Draw a solar hydrogen production efficiency spectrum flow chart for the present invention;

[0043] Figure 4 A structural block diagram of a device for calculating the efficiency limit value of Z-type heterojunction solar hydrogen production in an embodiment of the present invention;

[0044] Figure 5 The present invention traverses the energy band gap of two monolayers to obtain the solar hydrogen production efficiency limit spectrum of the Janus Z-type heterojunction;

[0045] Figure 6 The present invention traverses the energy band gap of two monolayers to obtain the solar hydrogen production efficiency spectrum of the ordinary Z-type heterojunction.

[0046] Description of main component symbols:

[0047] Parameter reading verification unit 10 Computational Unit 20 Mapping unit 30

[0048] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0049] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0050] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0052] like Figure 1 As shown, an embodiment of the present invention provides a method for calculating the efficiency limit value of Z-type heterojunction solar hydrogen production, the method comprising the following steps:

[0053] The present invention provides a method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production, the method comprising:

[0054] S101, reading vacuum energy level difference data and energy band data of a Z-type heterojunction input by a user;

[0055] S102, determining whether the vacuum energy level difference is equal to 0;

[0056] S103, when the vacuum energy level is not 0, the vacuum energy level difference and the energy band data are input into a second solar hydrogen production efficiency limit formula for calculation;

[0057] S104, the vacuum energy level difference is 0, and the energy band data is input into the first solar hydrogen production efficiency limit formula for calculation;

[0058] S105, obtaining the solar hydrogen production efficiency limit value of the Z-type heterojunction;

[0059] S106, traversing the parameter combinations according to the existing solar hydrogen production efficiency formula, automatically calculating the solar hydrogen production efficiency to generate a spectrum, and comparing and verifying its limit value.

[0060] The above method for calculating the efficiency limit of solar hydrogen production from a Z-type heterojunction achieves high-precision and reliable calculations by deriving a formula for the efficiency limit of solar hydrogen production and combining vacuum energy level difference data and energy band data input by the user.

[0061] In one embodiment of the present invention, see Figure 2 , the method further comprises the following steps:

[0062] S201, obtaining physical property parameter data of the Z-type heterojunction;

[0063] S202, calculating the solar energy hydrogen production efficiency limit values ​​corresponding to the physical property parameter data by using the two solar energy hydrogen production efficiency limit formulas, and plotting the corresponding solar energy hydrogen production efficiency limit values ​​into an efficiency analysis graph.

[0064] It should be noted that the efficiency analysis map includes contour line hierarchy maps. In the contour line hierarchy maps, different colors represent the size of the solar hydrogen production efficiency value (blue to red increases in sequence), which can be seen Figure 5 , Figure 6 By drawing an efficiency analysis graph, it is convenient to provide accurate suggestions for Z-type heterojunction adjustment in the later stage.

[0065] In one embodiment of the present invention, the physical property parameter data includes energy band structure parameters and redox reaction overpotential.

[0066] In one embodiment of the present invention, the energy band structure parameters include: valence band maximum, conduction band minimum, hydrogen evolution reaction overpotential, and oxygen evolution reaction overpotential.

[0067] In one embodiment of the present invention, the calculation formula for the minimum energy of photons that can participate in the redox reaction is:

[0068]

[0069] E min =0.615eV (2)

[0070] Where, χ(H2) is the overpotential of hydrogen evolution reaction, χ(O2) is the overpotential of oxygen evolution reaction, E g is the larger band gap between the two monolayers, E min is the minimum energy of a photon.

[0071] The minimum energy band gap formula corresponding to the limit value is:

[0072]

[0073] where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E min is the minimum energy value of the photon, and ΔΦ is the potential difference between the upper and lower surface energy levels.

[0074] In one embodiment of the present invention, the calculation formula for the minimum energy of photons that can participate in the redox reaction is:

[0075] E g1 ≈E g2 ≈0.615eV (1)

[0076] E g1 +E g2 ≥1.23eV (2)

[0077]

[0078] Among them, E g1 and E g2 are the energy band gaps of two monolayers, E min is the minimum energy of the photon that can participate in the reaction.

[0079] In one embodiment of the present invention, the step of calculating the solar hydrogen production efficiency limit values ​​of all the physical parameter data by using the two solar hydrogen production efficiency limit formulas comprises:

[0080] S301, distribute all physical property parameter data in multiple parameter spaces, sample or discretize the physical property parameter data in the multiple parameter spaces, and calculate the corresponding solar hydrogen production efficiency value for each physical property parameter data. Specifically, the relevant physical property parameters are segmented and sampled within a certain range, and the energy band gap of two monolayers is divided into 300 parts in (0-3eV) by 0.01eV, and meshed using the meshgrid function.

[0081] In one embodiment of the present invention, the step of plotting all solar hydrogen production efficiency limit values ​​into an efficiency analysis graph includes: S302, using Matplotlib library to plot the efficiency analysis graph.

[0082] As described above, after traversing all discrete values ​​in the physical property parameter space, it is certain that the corresponding parameter to the user input can be found. Then, by comparing the physical property parameters corresponding to the limit value of solar hydrogen production efficiency, suggestions for improving solar hydrogen production efficiency can be given.

[0083] Figure 5 The spectrum of the Janus Z-type heterojunction when the vacuum energy level difference is 1.22eV. Figure 6The diagram shows a common Z-type heterojunction. It should be noted that the white five-pointed star represents the position of the gap between the two monolayer energy bands of the material, and the black five-pointed star represents the position of the solar hydrogen production efficiency limit of the material.

[0084] It should be noted that the graph drawing unit 30 can use the Matplotlib library in the Python programming language to draw the graph. The data used comes from the traversal calculation of different physical property parameter ranges, including material band structure parameters and electrostatic potential difference.

[0085] In one embodiment of the present invention, the method further comprises:

[0086] Combined with the current solar hydrogen production efficiency of the Z-type heterojunction and the solar hydrogen production efficiency limit value, specific methods and suggestions on how to change the physical parameters to improve the solar hydrogen production efficiency are generated.

[0087] The present invention also provides a device for calculating the efficiency limit of Z-type heterojunction solar hydrogen production, the device comprising:

[0088] A parameter reading unit 10 is used to read the vacuum energy level difference data and energy band data of the Z-type heterojunction input by the user to obtain the necessary parameters of the Z-type heterojunction;

[0089] A calculation unit 20, for inputting the vacuum energy level difference data into a solar hydrogen production efficiency limit formula for calculation, and obtaining a solar hydrogen production efficiency limit value of the Janus material;

[0090] A graph drawing unit 30 is used to take the physical property parameter set as input, calculate the solar hydrogen production efficiency limit values ​​of all the physical property parameters, and draw a graph (efficiency analysis graph) showing the solar hydrogen production efficiency of the Z-type heterojunction as a function of different physical property parameters according to the limit values ​​of all the physical property parameters;

[0091] The above-mentioned device for calculating the efficiency limit of solar hydrogen production of Z-type heterojunction reads the vacuum energy level difference data and energy band data of the Z-type heterojunction input by the user through a parameter reading unit to obtain the necessary parameters of the Z-type heterojunction, and then inputs the vacuum energy level difference data into the solar hydrogen production efficiency limit formula for calculation through a calculation unit, and obtains the solar hydrogen production efficiency limit value of the Z-type heterojunction, thereby achieving high-precision and reliable calculation.

[0092] It should be noted that, in one embodiment of the present invention, the method for determining the limit formula of solar hydrogen production efficiency can be: for the lower limit E of the integrand, the smaller E is, the larger the integral value is. It can be seen from formula (1) that in the four cases of calculating E, to minimize the E value, only when χ(H2)=0.2eV, χ(O2)=0.2eV, E minThe minimum energy value of a photon is given by formula (2), and the minimum energy band gap corresponding to the limit value is given by formula (3). Combining formulas (1), (2), and (3), a unified formula (4) is derived for calculating the limit value of solar hydrogen production efficiency for the Janus Z-type heterojunction.

[0093]

[0094] E min =0.615eV (2)

[0095]

[0096] Where χ(H2) and χ(O2) are the redox overpotentials of water, ΔG is the free energy difference of 1.23 eV for water splitting. is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E g is the energy band gap of the material, E min is the minimum energy of photons, and ΔΦ is the potential difference between the upper and lower surface energy levels.

[0097] Through precise mathematical and physical analysis, the present invention derives a unified formula for scientifically and accurately calculating the efficiency limit of Janus heterojunction solar hydrogen production and providing optimization guidance.

[0098] What is certain is that each electrostatic potential difference has its corresponding limit value of solar hydrogen production efficiency. Therefore, the physical parameter of the electrostatic potential difference is spatially discretized and traversed to obtain the corresponding limit value of solar hydrogen production efficiency, that is, the maximum value is the limit value of the material.

[0099] It should be noted that, in one embodiment of the present invention, the method for determining the solar hydrogen production efficiency limit formula may be:

[0100] When E g1 Approximately equal to E g2 When it is approximately equal to 0.615 eV, we get formula (1), when E g1 +E g2 When it is greater than or equal to 1.23 eV, we can obtain formula (2) and get E min Formula (3) is used to derive the unified formula (4) for calculating the efficiency limit of Z-type heterojunction solar hydrogen production from (1)(2)(3).

[0101] E g1 ≈E g2 ≈0.615eV (1)

[0102] E g1 +Eg2 ≥1.23eV (2)

[0103]

[0104] Among them, E g1 and E g2 are the energy band gaps of two monolayers, E min is the minimum energy of the photon that can participate in the reaction, ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E min is the minimum energy of a photon.

[0105] It should be noted that the efficiency of solar hydrogen production is divided into theoretical efficiency and experimental efficiency calculations, and there are significant differences in the calculation methods of the two. This method is a theoretical efficiency calculation, which is usually calculated through the conversion relationship between light energy and chemical energy. It focuses on the maximum conversion of light energy into hydrogen chemical energy under ideal conditions. This theoretical efficiency calculation method usually does not take into account energy loss, such as incomplete light absorption, reactor heat loss, etc., and estimates the upper limit value based on the optimal state of the material's photocatalytic performance.

[0106] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production, characterized in that: The method comprises: Read the vacuum energy level difference data and energy band data of the Z-type heterojunction input by the user; Inputting the vacuum energy level difference data into a first solar hydrogen production efficiency limit formula for calculation to obtain the solar hydrogen production efficiency limit value of the Z type; The first solar hydrogen production efficiency limit formula is as follows: where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential of , ΔΦ is the potential difference between the upper and lower surface energy levels.

2. A method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production, characterized in that: The method comprises: Read the two single-layer band structure data of the Z-type heterojunction input by the user; Inputting the energy band structure data into a second solar hydrogen production efficiency limit formula for calculation to obtain the solar hydrogen production efficiency limit value of the Z type; The second solar hydrogen production efficiency limit formula is as follows: where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E min is the minimum energy of a photon.

3. The method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production according to claim 1, characterized in that: The method comprises: Acquiring physical property parameter data of the Z-type heterojunction; The solar hydrogen production efficiency limit values ​​of all the physical parameter data are calculated by the first solar hydrogen production efficiency limit formula, and all the solar hydrogen production efficiency limit values ​​are plotted into an efficiency analysis graph.

4. A method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production according to claim 3, characterized in that: The physical property parameter data include energy band structure parameters and redox reaction overpotential.

5. The method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production according to claim 3, characterized in that: The calculation formula for the minimum energy of photons that can participate in the reaction is: E min =0.615eV (2) Where, χ(H2) is the overpotential of hydrogen evolution reaction, χ(O2) is the overpotential of oxygen evolution reaction, E g is the larger band gap of the two monolayers.

6. According to claim 5, the method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production is characterized in that: The minimum energy band gap formula corresponding to the limit value is: where ΔG is the free energy difference of 1.23 eV for water splitting, is the photon energy The AM1.5G solar flux at is the energy of the photon The differential, E min is the minimum energy value of the photon, and ΔΦ is the potential difference between the upper and lower surface energy levels.

7. A method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production according to claim 5, characterized in that: The solar hydrogen production efficiency limit formula of the first Z-type heterojunction is: a plurality of solar hydrogen production efficiency values ​​are obtained by traversing the energy band gap, and the energy band gap corresponding to the maximum value is used as the formula parameter of the solar hydrogen production efficiency limit of the Z-type heterojunction.

8. A method for calculating the efficiency limit of Z-type solar hydrogen production according to claim 3, characterized in that: The step of calculating the solar energy hydrogen production efficiency limit values ​​of all the physical parameter data by using the first solar energy hydrogen production efficiency limit formula comprises: All physical property parameter data are distributed in a plurality of parameter spaces, the physical property parameter data in the plurality of parameter spaces are sampled or discretized, and a corresponding solar hydrogen production efficiency value is calculated for each physical property parameter data.

9. The method for calculating the efficiency limit of Z-type heterojunction solar hydrogen production according to claim 3, characterized in that: The step of plotting all solar hydrogen production efficiency limit values ​​into an efficiency analysis graph comprises: using the Matplotlib library to plot the efficiency analysis graph.

10. A method and device for calculating the efficiency limit of two Z-type heterojunction solar hydrogen production, characterized in that: The device comprises: A parameter reading unit, which reads the vacuum energy level difference data and energy band data of the Z-type heterojunction input by the user to obtain the necessary parameters of the Z-type heterojunction; The calculation unit inputs the vacuum energy level difference data and the energy band data into a solar hydrogen production efficiency limit formula for calculation, and obtains the solar hydrogen production efficiency limit value of the Z-type heterojunction.

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