阅读说明：本技术 计算实验条件下二维材料表面吸附多样性的系统及方法 (System and method for calculating surface adsorption diversity of two-dimensional material under experimental condition ) 是由 张瑞丰 陈澍 富忠恒 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种计算实验条件下二维材料表面吸附多样性的系统及方法,计算方法通过分析二维材料的所处的实验环境,将其官能团的形成能与对应化学势建立起关系,然后枚举所有可能的表面构型,保存每一个不同表面官能团比例和排列的结构,并对所述结构进行弛豫,计算对应的形成能。通过高通量计算,建立二维材料在实验条件下的形成能数据库,并筛选出实验条件下相同化学势范围内具有最低形成能的官能团的比例以及对应的构型。本发明系统实现了将不同官能团形成能统一为一个计算公式的方法,及运用高通量技术计算实验条件下二维材料表面官能团的形成能；本发明方法能够更加精准的筛选具有优异的热力学稳定性的二维材料的表面构型,对新材料设计提供有利的帮助。(The invention discloses a system and a method for calculating surface adsorption diversity of a two-dimensional material under experimental conditions. Through high-throughput calculation, a formation energy database of the two-dimensional material under experimental conditions is established, and the proportion of the functional groups with the lowest formation energy and the corresponding configuration in the same chemical potential range under the experimental conditions are screened out. The system realizes a method for unifying the formation energy of different functional groups into a calculation formula, and calculates the formation energy of the functional groups on the surface of the two-dimensional material under the experimental condition by using a high-throughput technology; the method can more accurately screen the surface configuration of the two-dimensional material with excellent thermodynamic stability, and provides favorable help for the design of new materials.)

1. A system for calculating the surface adsorption diversity of a two-dimensional material under experimental conditions, namely a TDMSAS system; the method is characterized in that: the device comprises a pretreatment module, a surface functional group adding module, a structure relaxation processing module, a two-dimensional material structure type selecting module and a high-throughput calculating module;

the preprocessing module is used for setting input information required by a tested object after the TDMSAS system is initialized;

the two-dimensional material structure type selection module sets the two-dimensional material structure type according to the tested object and the experimental environment;

the surface functional group adding module reads an existing database stored in the tomsk software on the first aspect; secondly, adding matched functional group information according to the structure type of the two-dimensional material to obtain the two-dimensional material to be detected;

the structure relaxation processing module is used for converting surface functional groups of the two-dimensional material to be detected, storing all structures after conversion for relaxation, and calculating to obtain corresponding formation energy;

when a material surface is in a stable state, the surface is not stationary on a microscopic scale but is in a dynamic equilibrium process of continuous adsorption and desorption, so that a change range for stabilizing the surface configuration should be determined by a thermodynamic analysis method;

when two-dimensional material Ti₂CT_nIn the state of chemical equilibrium, the total energy can be related to the chemical potential by:

is a two-dimensional material Ti₂CT_nMedium titanium carbide Ti₂The chemical potential of C;

m is the number of adsorbed functional groups in one unit cell;

μ is the chemical potential of surface adsorption;

μ_Tis the chemical potential of surface adsorption of an atomic or molecular functional group;

E(Ti₂CT_n) Is Ti₂CT_nTotal energy of (d);

two-dimensional material Ti₂CT_nSatisfies the following relationship:

is a two-dimensional material Ti₂CT_nMedium titanium carbide Ti₂The chemical potential of C;

is thatMaximum value of (a), i.e. maximum chemical potential;

E(Ti₂C)is bare Ti₂Total energy of C; i.e. Ti₂CT_nMiddle Ti₂The maximum value of the chemical potential of C is equal to the bare Ti₂Total energy of C;

combining the formula (2) and the formula (1), obtaining the minimum value min (mu) of the chemical potential of the corresponding functional group_T) Comprises the following steps:

on the other hand, by the same method as the formula (2), the maximum value approximate estimate max (. mu.) of the chemical potential of the functional group is obtained_T) Comprises the following steps:

E(T₂) Is the total energy of the functional group in the corresponding gas state;

two-dimensional material Ti₂CT_nAdsorption energy of (D) is denoted as E_b：

m is the number of adsorbed functional groups in one unit cell;

combining equation (3) and equation (4), a range of chemical potentials is obtained that stabilizes the surface functional groups, namely:

the Ti₂CT_nFormation energy of (E)_f：

μ is the chemical potential of surface adsorption;

Δ μ is the chemical potential of surface adsorption obtained with the gas as a reference state;

since the total energy of a water molecule can be written as the form E (H) with the addition of chemical potentials₂O)＝2Δμ_H+Δμ_OThe relationship between the formation energy of water and the chemical potential is obtained, namely:

E(H₂o) is the total energy of an isolated water molecule;

E_f(H₂o) is the energy of formation of water;

μ_His the chemical potential of hydrogen;

Δμ_His the chemical potential of hydrogen in solution;

μ_Ois the chemical potential of oxygen;

Δμ_Ois the chemical potential of oxygen in solution;

μ_Fis the chemical potential of fluorine;

Δμ_Fis the chemical potential of fluorine in solution;

μ_OHis the chemical potential of hydroxyl;

Δμ_OHis the chemical potential of hydroxyl in solution;

chemical potential of oxygen in solution Δ μ_OChemical potential of fluorine Δ μ_FAnd the chemical potential of hydroxyl group Δ μ_OHChemical potential of hydrogen Δ μ_HThe inverse relationship:

Δμ_O＝E_f(H₂O)-2Δμ_H (9)

Δμ_F＝E_f(HF)-Δμ_H (10)

Δμ_OH＝E_f(H₂O)-Δμ_H (11)

chemical potential of hydrogen, Δ μ when the pH in solution is not zero_HThis can be obtained by the following formula:

Δμ_H＝G(pH)＝kTln[H⁺]＝-kTln10×pH (12)

g is Gibbs free energy;

k is the Boltzmann constant;

after screening the energies of the different structures through high flux, comparing the energies of the structures, taking the structure with the lowest energy in each proportion as the most stable structure in the proportion, and calculating the formation energy of each proportion by using the energy; finally, drawing a diagram of structure formation energy-chemical potential under different functional group proportions, and obtaining the most stable surface adsorption configuration by comparing the size relationship of the energy formed under the same chemical potential;

the high-throughput calculation module adopts a high-throughput calculation mode to establish a functional group formation energy database of the two-dimensional material under the experimental condition, and screens out the proportion and the configuration of the functional group with the lowest formation energy in the same chemical potential range under the experimental condition.

2. The system for calculating the adsorption diversity of a two-dimensional material surface under experimental conditions of claim 1, wherein: the measured object is a two-dimensional material Ti₂CT_nSaid Ti₂CT_nWherein T is oxygen O, fluorine F or hydroxyl OH; the subscript n is the atomic number of the element T.

3. The system for calculating the adsorption diversity of a two-dimensional material surface under experimental conditions of claim 1, wherein: the input information needs to have at least a crystal structure, a rectangular coordinate system, a total number of atoms, an atom type, a superlattice size, and each atom coordinate.

4. The system for calculating the adsorption diversity of a two-dimensional material surface under experimental conditions of claim 1, wherein: the two-dimensional material structure type is two-dimensional material Ti₂CT_nOf Ti, a two-dimensional material₂CT_nAdsorption diversity of surface functional groups in hydrofluoric acid solution environmentAnd (4) calculating.

5. The system for calculating the adsorption diversity of a two-dimensional material surface under experimental conditions of claim 1, wherein: and establishing a database of functional group formation energies of the obtained two-dimensional material under experimental conditions, wherein the database is called a supplementary database. The supplementary database is added to the existing structure library to form an updated database.

6. A method for calculating the surface adsorption diversity of a two-dimensional material under experimental conditions is characterized by comprising the following steps: the method comprises the following steps:

analyzing the experimental environment of the two-dimensional material, and establishing the relationship between the formation energy of surface functional groups and the corresponding chemical potential;

step two, enumerating the surface hybrid functional groups of the two-dimensional material under different functional group ratios to all different arrangement sequences, and storing each structure to obtain the two-dimensional material carrying the functional groups;

relaxing the two-dimensional material carrying the functional group, and calculating to obtain corresponding formation energy;

screening out a structure library of the two-dimensional material based on the existing structure library; establishing a functional group formation energy database of the two-dimensional material under experimental conditions through high-throughput calculation, and screening out the proportion and the configuration of a functional group with the lowest formation energy in the same chemical potential range under the experimental conditions;

the third step is realized as follows:

step 31, pretreatment: determining the proportion of surface mixed functional groups, and reading input information required by the object to be measured from the existing structure library;

the measured object is a two-dimensional material with a determined name;

the input information at least needs to have a crystal structure, a rectangular coordinate system, the total number of atoms, an atom type, the size of a supercell lattice and each atom coordinate; the input information is read from the atomsk software;

step 32, judging whether the object to be measured is a two-dimensional material with a vacuum layer thick enough and a direction in a z-axis;

if yes, go to step 33, otherwise, carry on the structural optimization;

if the material is not a two-dimensional material, directly returning to the step 31 to read the next structure file;

if the z-axis is not the direction of the vacuum layer, adjusting the basis vector to make the vacuum layer in the z-axis direction, and turning to step 33;

if the thickness of the vacuum layer is less thanIncreasing the size of the vacuum layer, and turning to step 33;

the two-dimensional material refers to a material of which electrons can move freely and planarly only on the nanometer scale of 1-100 nm in two dimensions;

the vacuum layer refers to the out-of-plane direction when a two-dimensional material model is established in the calculation process;

step 33, relaxing the structure; in order to ensure that the thickness of the vacuum layer is unchanged, the basis vector perpendicular to the z direction of the two-dimensional material is not relaxed;

step 34, changing the arrangement sequence of the surface functional groups, introducing a new structure, and repeating the steps 31 to 33 until all the structures are input; calculating and screening out the two-dimensional material with the lowest capability under the functional group proportion;

and 35, changing the proportion of the hybrid surface functional groups, repeating the steps 31 to 34 until the proportion of all the functional groups is calculated, and comparing and screening the proportions of the functional groups of the two-dimensional material with the lowest formation energy under the same chemical potential.

7. The method of claim 6, wherein the method comprises the steps of: the sufficient thickness means that the thickness of the vacuum layer reaches the thickness of the vacuum layerThe above.

Technical Field

The invention relates to the technical field of two-dimensional materials, in particular to a system and a method for calculating surface adsorption diversity of a two-dimensional material under an experimental condition.

Background

The Two-dimensional material (Two dimensional material) is named as a Two-dimensional atomic crystal material, and refers to a material in which electrons can move freely (planar motion) only on a Two-dimensional nanoscale (1-100 nm), such as a nano-film, a superlattice, and a quantum well. Two-dimensional materials were proposed with the success of isolating a single atomic layer of graphene (graphene), a graphite material by the Geim group at the university of Manchester in 2004.

Surface adsorption (surface adsorption) refers to an adsorption phenomenon that occurs on the surface of a solution due to the difference in the concentration of a solute on the surface layer of the solution and the concentration of the solute in the solution.

In the process of preparing a two-dimensional material, the distribution of the surface functional groups of the material can be changed due to the change of the preparation conditions of the material. Two-dimensional materials obtained by different preparation methods have obvious difference in electrochemical stability and properties. Theoretical calculation shows that the thermodynamic stability, electronic properties and even intercalation mechanism of the two-dimensional material are closely related to the surface terminal of the two-dimensional material. Experimental characterization means such as neutron scattering, NMR spectroscopy and X-ray photoelectron spectroscopy (XPS) prove that multiple functional groups coexist on the surface of the two-dimensional material instead of a single type of functional group. However, it was found by search that The model modeling of single functional groups mostly used in previous studies, [ Ashton M, Mathew K, Hennig R G, Sinntott S B, The Journal of Physical Chemistry C120 (2016) 3550-; yu Y-X.the Journal of Physical Chemistry C120 (2016) 5288-. Therefore, in order to better understand the mechanism of complex surface structure formation under theoretical and experimental conditions, a systematic and deep physicochemical view is urgently needed.

Disclosure of Invention

One of the purposes of the invention is to design a system for calculating the adsorption diversity of the surface of a two-dimensional material under experimental conditions. The system establishes a relationship between the formation energy of functional groups of the two-dimensional material and corresponding chemical potential by analyzing the experimental environment of the two-dimensional material, enumerates all possible surface configurations, stores the structures with different surface functional group ratios and arrangements, relaxes the structures, and calculates the corresponding formation energy. Through high-throughput calculation, a formation energy database of the two-dimensional material under experimental conditions is established, and the proportion of the functional groups with the lowest formation energy and the corresponding configuration in the same chemical potential range under the experimental conditions are screened out.

The invention also aims to provide a method for calculating the surface adsorption diversity of the two-dimensional material under the experimental condition, which comprises a method for calculating the most stable surface functional group ratio of the two-dimensional material under the experimental condition by using thermodynamics, and screens out the most stable surface configuration of the two-dimensional material under each functional group ratio by using a high-throughput technology.

The invention relates to a system for calculating the surface adsorption diversity of a two-dimensional material under experimental conditions, namely a TDMSAS system; the method is characterized in that: the device comprises a pretreatment module, a surface functional group adding module, a structure relaxation processing module, a two-dimensional material structure type selecting module and a high-throughput calculating module;

the preprocessing module is used for setting input information required by a tested object after the TDMSAS system is initialized;

the two-dimensional material structure type selection module sets the two-dimensional material structure type according to the tested object and the experimental environment;

the surface functional group adding module reads an existing database stored in the tomsk software on the first aspect; secondly, adding matched functional group information according to the structure type of the two-dimensional material to obtain the two-dimensional material to be detected;

the structure relaxation processing module is used for converting surface functional groups of the two-dimensional material to be detected, storing all structures after conversion for relaxation, and calculating to obtain corresponding formation energy;

the high-throughput calculation module adopts a high-throughput calculation mode to establish a functional group formation energy database of the two-dimensional material under the experimental condition, and screens out the proportion and the configuration of the functional group with the lowest formation energy in the same chemical potential range under the experimental condition.

The invention discloses a method for calculating surface adsorption diversity of a two-dimensional material under experimental conditions, which is characterized by comprising the following steps of: the method comprises the following steps:

analyzing the experimental environment of the two-dimensional material, and establishing the relationship between the formation energy of surface functional groups and the corresponding chemical potential;

step two, enumerating the surface hybrid functional groups of the two-dimensional material under different functional group ratios to all different arrangement sequences, and storing each structure to obtain the two-dimensional material carrying the functional groups;

relaxing the two-dimensional material carrying the functional group, and calculating to obtain corresponding formation energy;

screening out a structure library of the two-dimensional material based on the existing structure library; establishing a functional group formation energy database of the two-dimensional material under experimental conditions through high-throughput calculation, and screening out the proportion and the configuration of a functional group with the lowest formation energy in the same chemical potential range under the experimental conditions;

the third step is realized as follows:

step 31, pretreatment: determining the proportion of surface mixed functional groups, and reading input information required by the object to be measured from the existing structure library;

the measured object is a two-dimensional material with a determined name;

the input information at least needs to have a crystal structure, a rectangular coordinate system, the total number of atoms, an atom type, the size of a supercell lattice and each atom coordinate; the input information is read from the atomsk software;

step 32, judging whether the object to be measured is a two-dimensional material with a vacuum layer thick enough and a direction in a z-axis;

if yes, go to step 33, otherwise, carry on the structural optimization;

if the material is not a two-dimensional material, directly returning to the step 31 to read the next structure file;

if the z-axis is not the direction of the vacuum layer, adjusting the basis vector to make the vacuum layer in the z-axis direction, and turning to step 33;

if the thickness of the vacuum layer is less thanIncreasing the size of the vacuum layer, and turning to step 33;

the two-dimensional material refers to a material of which electrons can move freely and planarly only on the nanometer scale of 1-100 nm in two dimensions;

the vacuum layer refers to the out-of-plane direction when a two-dimensional material model is established in the calculation process;

step 33, relaxing the structure; in order to ensure that the thickness of the vacuum layer is unchanged, the basis vector perpendicular to the z direction of the two-dimensional material is not relaxed;

step 34, changing the arrangement sequence of the surface functional groups, introducing a new structure, and repeating the steps 31 to 33 until all the structures are input; calculating and screening out the two-dimensional material with the lowest capability under the functional group proportion;

and 35, changing the proportion of the hybrid surface functional groups, repeating the steps 31 to 34 until the proportion of all the functional groups is calculated, and comparing and screening the proportions of the functional groups of the two-dimensional material with the lowest formation energy under the same chemical potential.

The invention has the advantages that:

the method can screen the two-dimensional material with the most stable thermodynamics and the hybrid functional group, and provides favorable help for the design of new materials.

The TDMSAS system constructed by the invention realizes the calculation of the surface thermodynamic stability in actual conditions and the calculation of the most stable configuration of the two-dimensional material under different functional group proportions by using a high-throughput technology.

The TDMSAS system can reduce the experiment cost and greatly shorten the new material research and development application period through high-throughput calculation. High throughput calculations can be applied to screen two-dimensional materials with high desired strength.

Drawings

FIG. 1 is a flow chart of the calculation of the adsorption diversity of the two-dimensional material surface under the experimental conditions of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

In order to realize the calculation of the surface adsorption of the two-dimensional material under the experimental condition, the invention adopts a Win7 operating system to perform the distribution simulation modeling of the surface functional groups of the two-dimensional material on a matlab (version number 7.13) platform in combination with atom-msk software (molecular/atomic modeling in the chemical field), so as to obtain a system for calculating the surface adsorption diversity of the two-dimensional material under the experimental condition. In the invention, a calculation system for the surface adsorption diversity of the two-dimensional material under the experimental condition is referred to as TDMSAS system. And providing the surface functional group information of the two-dimensional material for the measured object by using the atom-msk software. The TDMSAS system can reduce time-consuming and high-cost experiments by adopting high-throughput calculation, greatly shorten the period of research and development of new materials, and has an important effect on the progress and development of a material genome project (MGI).

High-throughput computing integrates data, codes, computing tools, and the like in a material design process to achieve sharing, thereby accelerating the development of new materials.

In the invention, the two-dimensional material surface adsorption diversity generation module is used for generating parameters of two-dimensional material surface hybrid functional group adsorption diversity of the object to be tested in matlab software and outputting the parameters in a file form.

In the present invention, the file output by the two-dimensional material surface adsorption diversity generation module can be applied to a material genome project (MGI).

Referring to fig. 1, the system for calculating the surface adsorption diversity of a two-dimensional material under experimental conditions (TDMSAS system) of the present invention includes a preprocessing module, a surface functional group adding module, a structure relaxation processing module, a two-dimensional material structure type selecting module, and a high-throughput calculating module.

Pre-processing module

The preprocessing module is used for setting input information required by the tested object after the TDMSAS system is initialized.

The measured object is a two-dimensional material Ti₂CT_nSaid Ti₂CT_nWherein T is oxygen O, fluorine F or hydroxyl OH; the subscript n is the atomic number of the element T. Such as Ti₂CO₂(ii) a Such as Ti₂CF₂(ii) a Such as Ti₂C(OH)₂。

The input information needs to have at least a crystal structure, a rectangular coordinate system, a total number of atoms, an atom type, a superlattice size, and each atom coordinate.

Two-dimensional material structure type selection module

The two-dimensional material structure type selection module sets the two-dimensional material structure type according to the tested object and the experimental environment;

for example, a two-dimensional material Ti₂CT_nAnd (4) calculating the adsorption diversity of the surface functional groups in the hydrofluoric acid solution environment.

Surface functional group addition module

The surface functional group adding module reads an existing database stored in the tomsk software on the first aspect; and secondly, adding matched functional group information according to the structure type of the two-dimensional material to obtain the two-dimensional material to be detected.

In the present invention, the database refers to two-dimensional material data containing different ratios of functional groups.

Structure relaxation processing module

And the structure relaxation processing module is used for converting surface functional groups of the two-dimensional material to be detected, storing all structures after conversion, relaxing and calculating to obtain corresponding formation energy.

In the process of calculating the surface adsorption diversity of the two-dimensional material in the TDMSAS system, a method for calculating the most stable surface functional group ratio of the two-dimensional material under experimental conditions by thermodynamics is used, and the most stable surface configuration of the two-dimensional material under each functional group ratio is screened out by a high-throughput first principle calculation technology.

In the present invention, two-dimensional material Ti is used₂CT_nIn a hydrofluoric acid solution environment for example. The Ti₂CT_nWherein T is oxygen O, fluorine F or hydroxyl OH; the subscript n is the atomic number of the element T.

When a material surface is in a stable state, the surface is not stationary on a microscopic scale but is in a dynamic equilibrium process of continuous adsorption and desorption, so a thermodynamic analysis method should be used to determine a variation range for stabilizing the surface configuration.

When two-dimensional material Ti₂CT_nIn the state of chemical equilibrium, the total energy can be related to the chemical potential by:

is a two-dimensional material Ti₂CT_nMedium titanium carbide Ti₂Chemical potential of C.

m is the number of adsorbed functional groups in one unit cell.

μ is the chemical potential of surface adsorption.

μ_TIs the chemical potential of surface adsorption of an atomic or molecular functional group (element T).

E(Ti₂CT_n) Is Ti₂CT_nTotal energy of (c).

In the present invention, it should be noted that Ti is added to ensure that there is a stable range of variation in the surface functional groups₂CT_nMiddle Ti₂C is regarded as independent of Ti₂CT_nAs a whole.

Due to the chemical potential of the solution mu_TDetermining the limits of chemical potential changes is an important process, depending on the ion concentration in the solution environment, since this provides not only an estimate of the practical system upper and lower limits, but also an estimate of the practical system upper and lower limitsCan be at chemical potential mu_TProvides a well-defined theoretical reference point on the axis of (a). Such as Ti₂CO₂When the chemical potential of oxygen is μ_OAt very low levels, the oxygen functionality becomes unstable, and this applies to all other types of functionality. The functional group is unstable to Ti₂CT_nDecomposed into bare Ti₂C and gas state (O) corresponding to functional group₂、F₂And/or O₂+H₂) The two parts, in this case the two-dimensional material Ti₂CT_nSatisfies the following relationship:

is a two-dimensional material Ti₂CT_nMedium titanium carbide Ti₂Chemical potential of C.

Is mu_Ti2CI.e. the maximum chemical potential.

E(Ti₂C) Is bare Ti₂Total energy of C; i.e. Ti₂CT_nMiddle Ti₂The maximum value of the chemical potential of C is equal to the bare Ti₂Total energy of C.

Combining the formula (2) and the formula (1), obtaining the minimum value min (mu) of the chemical potential of the corresponding functional group_T) Comprises the following steps:

on the other hand, by the same method as the formula (2), the maximum value approximate estimate max (. mu.) of the chemical potential of the functional group is obtained_T) Comprises the following steps:

E(T₂) Is the total energy of the functional group in the corresponding gas state, i.e. O₂、F₂And/or O₂+H₂. That is to say that the maximum value of the chemical potential of the functional group is equal to half the total energy of the corresponding gaseous state.

In the present invention, the two-dimensional material Ti₂CT_nAdsorption energy of (D) is denoted as E_b：

m is the number of adsorbed functional groups in one unit cell.

Combining the maximum (formula (3)) and minimum (formula (4)) of the chemical potential of the functional group, a range of chemical potentials is obtained that stabilizes the surface functional group, namely:

for the purpose of deep discussion of adsorption of various Ti functional groups₂CT_nThe stability of (A), the Ti₂CT_nFormation energy of (E)_f：

μ is the chemical potential of surface adsorption.

Δ μ is the chemical potential of surface adsorption obtained with the gas as a reference state.

In the present invention, in the case of the present invention,is the chemical potential of the functional group obtained using a gas corresponding to the adsorbed atom or molecular functional group (element T) as a reference state.

However, in practice it is not appropriate to use a gas as a reference, since in Ti₂CT_nIn the preparation process of (2), the surface is in an environment of hydrofluoric acid aqueous solution, and under such a condition, there may occur a case where three functional groups (-O, -F and-OH) coexist. Since the total energy of a water molecule can be written as the form E (H) with the addition of chemical potentials₂O)＝2Δμ_H+Δμ_OThe relationship between the formation energy of water and the chemical potential is obtained, namely:

E(H₂o) is the total energy of an isolated water molecule.

E_f(H₂O) is the energy of formation of water.

μ_HIs the chemical potential of hydrogen.

Δμ_HIs the chemical potential of hydrogen in solution.

μ_OIs the chemical potential of oxygen.

Δμ_OIs the chemical potential of oxygen in solution.

μ_FIs the chemical potential of fluorine.

Δμ_FIs the chemical potential of fluorine in solution.

μ_OHIs the chemical potential of hydroxyl.

Δμ_OHIs the chemical potential of the hydroxyl radical in solution.

In the present invention, the chemical potential Δ μ of oxygen in solution is deduced_OChemical potential of fluorine Δ μ_FAnd the chemical potential of hydroxyl group Δ μ_OHChemical potential of hydrogen Δ μ_HThe inverse relationship:

Δμ_O＝E_f(H₂O)-2Δμ_H (9)

Δμ_F＝E_f(HF)-Δμ_H (10)

Δμ_OH＝E_f(H₂O)-Δμ_H (11)

and formula (6)) Similarly, the chemical potential of hydrogen in solution is Δ μ_HIs equal to 0eV and is generally considered the reference state. Due to the chemical potential of hydrogen Δ μ_HIs not independent in solution but is in chemical potential Δ μ with oxygen_OChemical potential of fluorine Δ μ_FAnd the chemical potential of hydroxyl group Δ μ_OHIn inverse relation, so its minimum value can be calculated by calculating the chemical potential Δ μ of the atomic or molecular function (element T) in solution_TIs obtained by a maximum value of_TIs 0, will be Δ μ_TSubstitution of 0 into equations (9) to (11) yields the chemical potential Δ μ of hydrogen_HThree sets of data of values. By comparing these three values, the hydrogen chemical potential Δ μ can be obtained_HAnd further obtaining a common range thereof.

In addition, to measure the chemical potential of hydrogen Δ μ_HA pH value was established in relation to a standard hydrogen electrode (solution pH 0, 1bar gaseous H at 298K)₂) Set to the reference state. Therefore, when the pH is equal to zero, the chemical potential of hydrogenEqual to zero. Chemical potential of hydrogen, Δ μ when the pH in solution is not zero_HThis can be obtained by the following formula:

Δμ_H＝G(pH)＝kTln[H⁺]＝-kTln10×pH (12)

g is Gibbs free energy.

k is the boltzmann constant.

Thus, the corresponding hydrogen chemical potential delta mu under any pH value can be obtained_H。

In the present invention, since the arrangement structure of the hybrid functional groups on the surface may be different at each ratio, Ti of different configurations appears₂CT₂. By adding Ti to each fluorine-oxygen ratio₂CT₂Enumerating all possible structures, and obtaining 300 different structures by adopting the method of the invention. After screening the energies of these different structures by high throughput, the energies of these structures are compared, and the structure with the lowest energy in each ratio is taken as the oneThe most stable structure at the ratio and this energy is used to calculate the formation energy for each ratio. And finally, drawing a graph of structure formation energy-chemical potential under different functional group ratios, and comparing the size relationship of the formation energy under the same chemical potential to obtain the most stable surface adsorption configuration.

High-throughput computing module

The high-throughput calculation module adopts a high-throughput calculation mode to establish a functional group formation energy database of the two-dimensional material under the experimental condition, and screens out the proportion and the configuration of the functional group with the lowest formation energy in the same chemical potential range under the experimental condition.

In the invention, the functional groups of the two-dimensional material output by the high-throughput computing module under the experimental conditions form an energy database, which is called a supplementary database. The supplemental database is added to the existing structural library of the tomsk software to form an updated database. And when the updated database is used for operating the TDMSAS system next time, the tested object is used as the existing structure library for calling.

The invention provides a method for calculating surface adsorption diversity of a two-dimensional material under experimental conditions, wherein the flow of the method is shown in figure 1, and the specific implementation comprises the following steps:

analyzing the experimental environment of the two-dimensional material, and establishing the relationship between the formation energy of surface functional groups and the corresponding chemical potential;

secondly, enumerating the surface hybrid functional groups of the two-dimensional material under different functional group ratios to all different arrangement sequences, and storing each structure to obtain the two-dimensional material to be detected carrying the functional groups;

relaxing the two-dimensional material carrying the functional group, and calculating to obtain corresponding formation energy;

screening out a structure library of the two-dimensional material based on the existing structure library; through high-throughput calculation, a functional group formation energy database of the two-dimensional material under experimental conditions is established, and the proportion and the configuration of the functional group with the lowest formation energy in the same chemical potential range under the experimental conditions are screened out.

The functional group formation energy database of the two-dimensional material established by the method under the experimental condition is called a supplementary database. The supplementary database is added to the existing structure library to form an updated database. And when the next calculation of the adsorption diversity of the two-dimensional material surface is carried out, the updated database is called as the existing structure library and is called by the measured object.

In the invention, the third step is realized as follows:

step 31, pretreatment: determining the proportion of surface mixed functional groups, and reading input information required by the object to be measured from the existing structure library;

the measured object is a two-dimensional material with a determined name; such as Ti₂CO₂(ii) a Such as Ti₂CF₂(ii) a Such as Ti₂C(OH)₂；

The input information at least needs to have a crystal structure, a rectangular coordinate system, the total number of atoms, an atom type, the size of a supercell lattice and each atom coordinate; the input information is read from the atomsk software.

Step 32, judging whether the object to be measured is a two-dimensional material with a vacuum layer thick enough and a direction in a z-axis;

if yes, go to step 33, otherwise, carry on the structural optimization;

if the material is not a two-dimensional material, directly returning to the step 31 to read the next structure file;

if the z-axis is not the direction of the vacuum layer, adjusting the basis vector to make the vacuum layer in the z-axis direction, and turning to step 33;

if the thickness of the vacuum layer is less thanThe size of the vacuum layer is increased, step 33.

The sufficient thickness means that the thickness of the vacuum layer reaches the thickness of the vacuum layerThe above.

In the invention, the two-dimensional material refers to a material of which electrons can move freely and planarly only on the nanometer scale of 1-100 nm in two dimensions.

In the present invention, the vacuum layer refers to an out-of-plane direction when a two-dimensional material model is built in a calculation process.

Step 33, the structure is relaxed. To ensure that the thickness of the vacuum layer is constant, the basis vector perpendicular to the z-direction of the two-dimensional material does not relax.

And step 34, changing the arrangement sequence of the surface functional groups, introducing a new structure, and repeating the steps 31 to 33 until all the structures are input. And calculating and screening out the two-dimensional material with the lowest formation energy under the functional group ratio.

And 35, changing the proportion of the hybrid surface functional groups, repeating the steps 31 to 34 until the proportion of all the functional groups is calculated, and comparing and screening the proportions of the functional groups of the two-dimensional material with the lowest formation energy under the same chemical potential.