A simulation method and apparatus for evaluating the gas adsorption capacity of ZnO / rGO heterojunctions

Abstract

This invention discloses a method and apparatus for simulating the gas adsorption capacity of a ZnO / rGO heterojunction. The method includes constructing a ZnO / rGO heterojunction model and using density functional theory (DFT) to simulate the gas adsorption behavior on the surface of the ZnO / rGO heterojunction model. By constructing a ZnO / rGO heterojunction model and using DFT to simulate the adsorption behavior of gas molecules on the ZnO / rGO heterojunction surface, this invention calculates the adsorption capacity of gas molecules on the material surface. This provides an effective theoretical reference for material construction and subsequent applications, significantly shortens the experimental cycle, predicts experimental results in specific application areas (such as photocatalysis and gas sensing), reduces unnecessary experimental costs, and effectively improves experimental results.

Description

Technical Field

[0001] This invention relates to the fields of materials synthesis and chemistry, specifically to a method and apparatus for simulating the gas adsorption capacity of a ZnO / rGO heterojunction. Background Technology

[0002] In fields such as photocatalysis and gas sensing, the adsorption behavior of gas molecules on material surfaces and their performance differences are fundamental to material construction and application development. Currently, nano-ZnO has attracted the most attention due to its high specific surface area, high electron mobility, good chemical and thermal stability, wide bandgap (3.37 eV), and large exciton binding energy (60 meV), making it one of the most promising gas-sensitive, pressure-sensitive, and photocatalytic materials. However, the performance of commercially available pure nano-ZnO still has room for improvement in application. Graphene, due to its unique two-dimensional honeycomb lattice, large surface area (theoretical surface area of ​​2630 m² / g), and abundant surface groups (for adsorbing gas molecules), has made reduced graphene oxide (rGO) an ideal carbonaceous material choice for composite material preparation. ZnO / rGO heterojunctions are based on composite materials of metal oxides / graphene or their derivatives. Decorating graphene sheets with n-type metal oxides can lead to the formation of pn junctions, and the resulting novel nanostructures may exhibit performance far superior to that of individual materials. However, the reasons for the improved performance of ZnO / rGO heterojunction compared to pure ZnO in specialized fields (such as photocatalysis and gas sensing) are still unknown. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and apparatus for simulating the gas adsorption capacity of ZnO / rGO heterojunction.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] In a first aspect, the present invention provides a simulation method for evaluating the gas adsorption capacity of a ZnO / rGO heterojunction, comprising:

[0006] Construct a ZnO / rGO heterojunction model;

[0007] Density functional theory (DFT) was used to simulate the adsorption behavior of gas on the surface of a ZnO / rGO heterojunction model.

[0008] Furthermore, the construction of the ZnO / rGO heterojunction model includes:

[0009] Establishment of ZnO and graphene crystal models;

[0010] The ZnO and graphene crystal models are cross-sectioned to obtain ZnO and graphene faces. One carbon atom is removed and one carboxyl and hydroxyl group are added to the graphene face to obtain the rGO crystal face.

[0011] By superimposing ZnO planes and rGO crystal planes, a ZnO / rGO heterostructure model is obtained.

[0012] Furthermore, the ZnO and graphene crystal models are supercells composed of 42 and 28 atoms, respectively.

[0013] Furthermore, the ZnO / rGO heterojunction model is a periodic crystal model composed of 54 atoms.

[0014] Furthermore, all geometric models were simulated using the CASTEP module of Materials Studio software, with a plane wave shear energy of 340 eV, a K-point of 4×4×2, and an overall cell energy level greater than the minimum of 2×10. -6 The generalized gradient approximation (GGA / PBE) function is selected as the exchange correlation function, and all geometric models are optimized to obtain a steady-state structure. The geometric models include ZnO, graphene, ZnO facet, graphene facet, and ZnO / rGO heterojunction models.

[0015] Furthermore, the optimized dimensions of the ZnO geometric model are: in The unit of length is one order of magnitude smaller than a nanometer; all models are constructed using this unit. The vacuum layer.

[0016] Furthermore, the process of slicing the ZnO and multilayer graphene crystal models to obtain ZnO and graphene faces includes:

[0017] The ZnO is cross-sectioned with parameters U(-120) and V(-3-10) to obtain a ZnO surface; the dimensions of the ZnO surface are as follows.

[0018] The graphene is cut into sections, and the parameters are set to U(-130) and V(-4-10) to obtain graphene surfaces; the dimensions of the graphene surfaces are...

[0019] in, It is a unit of length measurement, an order of magnitude smaller than a nanometer.

[0020] Furthermore, the dimensions of the ZnO / rGO heterojunction model are... in It is a unit of length measurement, an order of magnitude smaller than a nanometer.

[0021] In a second aspect, the present invention provides a simulation apparatus for evaluating the gas adsorption capacity of a ZnO / rGO heterojunction, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the methods described above.

[0022] Thirdly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of any of the methods described above.

[0023] Compared with the prior art, the advantages of this invention are as follows:

[0024] This invention constructs a ZnO / rGO heterojunction model and uses density functional theory (DFT) to simulate the adsorption behavior of gas molecules on the ZnO / rGO heterojunction surface, calculating the adsorption capacity of gas molecules on the material surface. This provides an effective theoretical reference for material construction and subsequent applications, which can greatly shorten the experimental cycle, predict experimental effects in specific application fields (such as photocatalysis, gas sensing, etc.), reduce unnecessary experimental costs, and effectively improve experimental results. Attached Figure Description

[0025] Figure 1 This is a flowchart of a method for simulating the gas adsorption capacity of a ZnO / rGO heterojunction provided in Embodiment 1 of the present invention;

[0026] Figure 2 This is the optimized ZnO crystal model;

[0027] Figure 3 It is a crystal model optimized for the ZnO(002) plane;

[0028] Figure 4 It is the optimized crystal model of reduced graphene oxide;

[0029] Figure 5 It is a ZnO / rGO heterocrystalline model;

[0030] Figure 6 This is a surface adsorption model of acetone molecules on a ZnO surface;

[0031] Figure 7 This is a surface adsorption model of acetone molecules on a ZnO / rGO heterojunction.

[0032] Figure 8 This is a schematic diagram of the composition of the simulation device for the gas adsorption capacity of the ZnO / rGO heterojunction provided in Embodiment 2 of the present invention; Detailed Implementation

[0033] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1:

[0035] Traditional experimental material construction has limitations for concrete applications, consumes a lot of time, and requires numerous experiments. By simulating the adsorption behavior of gas molecules on the surface of composite materials, this study investigates the surface properties of gas molecule adsorption processes on pure ZnO and ZnO / rGO surfaces at the molecular and atomic level. Through simulation calculations, it helps to understand the adsorption morphology, interaction mode, and changes in adsorption strength on the ZnO / rGO material surface, laying a theoretical foundation for material construction and its practical application.

[0036] Specifically, see Figure 1 As shown, the simulation method for the gas adsorption capacity of the ZnO / rGO heterojunction provided in this embodiment mainly includes the following steps:

[0037] 101. Construct a ZnO / rGO heterojunction model;

[0038] 102. Density functional theory (DFT) was used to simulate the adsorption behavior of gas on the surface of a ZnO / rGO heterojunction model.

[0039] Therefore, this method constructs a ZnO / rGO heterojunction model and uses density functional theory (DFT) to simulate the adsorption behavior of gas molecules on the ZnO / rGO heterojunction surface, calculating the adsorption capacity of gas molecules on the material surface. This provides an effective theoretical reference for material construction and subsequent applications, can greatly shorten the experimental cycle, predict experimental effects in specific application fields (such as photocatalysis, gas sensing, etc.), reduce unnecessary experimental costs, and effectively improve experimental results.

[0040] In one specific embodiment, step 101 includes:

[0041] Import the ZnO and graphene crystal unit cell structures into Materials Studio software. After geometry optimization, the ZnO size is... ( Figure 2 ), calculate the section parameters as U(-120), V(-3-10) and U(-130), V(-4-10), respectively, and cut out the ZnO surface ( Figure 3 ) and single-layer graphene surface;

[0042] After slicing, a periodic surface model of ZnO composed of 42 atoms and monolayer graphene composed of 28 atoms was constructed, with dimensions of respectively. and in It is a unit of length measurement, an order of magnitude smaller than a nanometer, and all use [specific unit of length]. A surface model was constructed using a vacuum layer, with two cross-sections differing in size by less than 5% and both at 60-degree angles. Subsequently, density functional theory (DFT) was used to geometrically optimize the surface models of the ZnO surface and monolayer graphene to obtain a stable structure.

[0043] The geometrically optimized monolayer graphene was constructed by removing one carbon atom and adding a carboxyl group and a hydroxyl group to create a monolayer reduced graphene oxide. Finally, density functional theory (DFT) was used to geometrically optimize the surface model of the monolayer reduced graphene oxide to obtain a stable structure with dimensions of [missing information]. in It is a unit of length measurement, an order of magnitude smaller than a nanometer, and uses... Vacuum layer construction surface model ( Figure 4 );

[0044] Finally, the optimized monolayer reduced graphene oxide was stacked on the surface of ZnO(002), and then... A vacuum layer was constructed to form a size of The ZnO / rGO heterojunction model was geometrically optimized using density functional theory (DFT) to obtain a steady-state structure. The constructed surface model contains 54 atoms, of which 12 atoms on the ZnO(002) surface are allowed to relax during the geometric optimization process, while the Cartesian coordinates of the bottom two layers of atoms are fixed and relaxation is not allowed during the geometric optimization process. Figure 5 ).

[0045] In one specific embodiment, step 102 includes:

[0046] Density functional theory (DFT) was used to simulate the adsorption behavior of a single acetone molecule on the surface of a ZnO / rGO heterojunction model. Figure 7 );

[0047] A molecular structure model of acetone was constructed, and geometric optimization was performed using the DFT method to ensure that the molecular energy reached a state of equilibrium.

[0048] Acetone molecules were added to the optimized ZnO / rGO heterojunction model to simulate the adsorption of acetone gas molecules in a gas-sensitive reaction process. This was accomplished using the CASTEP module of Materials Studio software based on the DFT method, with the generalized gradient approximation GGA / PBE function selected as the exchange correlation function. Figure 6 and 7 As shown, the adsorption energies of pure ZnO and ZnO / rGO heterojunctions are calculated to determine the adsorption capacity of different materials; a larger negative adsorption energy indicates a more stable adsorption configuration and easier formation. The formula for calculating the acetone adsorption energy is as follows:

[0049] E ads =EZnO / rgo+acetone -E ZnO / rGO-E acetone (1)

[0050] In the formula, E ads E represents the adsorption energy of the ZnO / rGO heterojunction reacting with acetone molecules. ZnO / rgo+acetone E represents the formation energy of the ZnO / rGO heterojunction and the adsorbed acetone molecules. ZnO / rGO and E acetone The values ​​represent the formation energies of the ZnO / rGO heterojunction and acetone molecules, respectively. The calculated surface adsorption energies for pure ZnO and the ZnO / rGO heterojunction are -0.20 and -0.34, respectively. Clearly, the surface adsorption energy of the ZnO / rGO heterojunction is higher than that of pure ZnO, indicating that the surface composite material has a stronger adsorption capacity for acetone molecules. Therefore, it can be concluded that the adsorption capacity of gas molecules on the surface of the ZnO / rGO heterojunction is superior to that of pure ZnO.

[0051] Example 2:

[0052] See Figure 8 As shown, the redundancy robotic arm motion planning device provided in this embodiment includes a processor 81, a memory 82, and a computer program 83 stored in the memory 82 and executable on the processor 81, such as a redundancy robotic arm motion planning program. When the processor 81 executes the computer program 83, it implements the steps of Embodiment 1 described above, for example... Figure 1 The steps are shown.

[0053] For example, the computer program 83 can be divided into one or more modules / units, which are stored in the memory 82 and executed by the processor 81 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 83 in the redundant robotic arm motion planning device.

[0054] The processor 81 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0055] The memory 82 can be an internal storage unit of the redundant robotic arm motion planning device, such as a hard disk or memory. The memory 82 can also be an external storage device, such as a plug-in hard disk, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the redundant robotic arm motion planning device. Furthermore, the memory 82 can include both internal storage units and external storage devices. The memory 82 is used to store the computer program and other programs and data required by the redundant robotic arm motion planning device. The memory 82 can also be used to temporarily store data that has been output or will be output.

[0056] Example 3:

[0057] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method described in Embodiment 1.

[0058] The computer-readable medium shown can be any means that can contain, store, communicate, propagate, or transmit a program for use in or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, for example, by optically scanning the paper or other medium, then editing, interpreting, or otherwise processing it as necessary to obtain the program electronically, and then storing it in computer memory.

[0059] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A simulation method for evaluating the gas adsorption capacity of ZnO / rGO heterojunctions, characterized in that, include: Construct a ZnO / rGO heterojunction model; Density functional theory (DFT) was used to simulate the adsorption behavior of gas on the surface of a ZnO / rGO heterojunction model. The construction of the ZnO / rGO heterojunction model includes: Establishment of ZnO and graphene crystal models; The ZnO and graphene crystal models are cross-sectioned to obtain ZnO and graphene faces. One carbon atom is removed and one carboxyl and hydroxyl group are added to the graphene face to obtain the rGO crystal face. By superimposing ZnO planes and rGO crystal planes, a ZnO / rGO heterojunction model is obtained; The ZnO and graphene crystal models are supercells composed of 42 and 28 atoms, respectively; The ZnO / rGO heterojunction model is a periodic crystal model composed of 54 atoms; All geometric models were simulated using the CASTEP module of Materials Studio software, with a plane wave shear energy of 340 eV, a K-point of 4×4×2, and an overall unit cell energy level greater than the minimum of 2×10. -6 eV / atom, and the generalized gradient approximation GGA / PBE function is selected as the exchange correlation function. All geometric models are optimized to obtain a steady-state structure. The geometric models include ZnO, graphene, ZnO facet, graphene facet, and ZnO / rGO heterojunction models. The optimized geometric model of the ZnO has the following dimensions: in The unit of length is one order of magnitude smaller than a nanometer; all models are constructed using this unit. The vacuum layer; The process of slicing the ZnO and graphene crystal models to obtain ZnO and graphene faces includes: The ZnO is cross-sectioned with parameters U(-120) and V(-3-10) to obtain a ZnO surface; the dimensions of the ZnO surface are as follows. The graphene is cut into sections, and the parameters are set to U(-130) and V(-4-10) to obtain graphene surfaces; the dimensions of the graphene surfaces are... in, It is a unit of length measurement, one order of magnitude smaller than a nanometer; The ZnO / rGO heterojunction model has the following dimensions: in It is a unit of length measurement, an order of magnitude smaller than a nanometer.

2. A simulation device for evaluating the gas adsorption capacity of a ZnO / rGO heterojunction, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in claim 1.

3. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in claim 1.

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