CN111054185B

CN111054185B - Toxic gas adsorption device and preparation method thereof

Info

Publication number: CN111054185B
Application number: CN202010055385.7A
Authority: CN
Inventors: 李华伟; 严圣勇; 向奔
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2020-01-17
Filing date: 2020-01-17
Publication date: 2024-01-23
Anticipated expiration: 2040-01-17
Also published as: CN111054185A

Abstract

The application relates to the technical field of toxic gas adsorption, in particular to a toxic gas adsorption device and a preparation method thereof. A first aspect of the present application provides a toxic gas adsorption device, the device comprising: a silicon wafer; the nanometer groove is arranged on the front surface of the silicon wafer, the concave depth of the nanometer groove is 2-8nm, and the diameter of the nanometer groove is 2-3 mu m; and a glass substrate on which the back surface of the silicon wafer is bonded. The application provides a toxic gas adsorption device and a preparation method thereof, so that a plurality of toxic gases can be adsorbed simultaneously and can be reused.

Description

Toxic gas adsorption device and preparation method thereof

Technical Field

The application relates to the technical field of toxic gas adsorption, in particular to a toxic gas adsorption device and a preparation method thereof.

Background

The toxic gas is a toxic gas which is in a gaseous state at normal temperature and normal pressure or is extremely volatile and harmful to organisms. Toxic gases are generated in nature and manufactured artificially; artificially produced toxic gases are generally derived from industrial pollution, gases produced by the combustion of coal and petroleum and the putrefactive decomposition of biological materials. The artificial toxic gas has stimulation effect on respiratory tract and is easy to inhale and poison, and generally comprises ammonia, ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, carbon dioxide, hydrogen sulfide, photochemical smog and the like. For example: carbon monoxide (CO) is a product of incomplete combustion of carbonaceous materials such as coal, petroleum, etc., and is a colorless, odorless, non-irritating toxic gas. Nitrogen dioxide (nitrogen dioxide), formula NO ₂ . Brownish red toxic gas at high temperature. Nitrogen dioxide and dinitrogen tetroxide coexist at normal temperature (0-21.5 ℃), and are toxic and irritant toxic gases. Formaldehyde is colorless and has a stimulating gas, and has a chemical formula of HCHO or CH ₂ O is colorless and has stimulating effect on eyes, nose and the like.

The prior art generally adopts the modes of physical adsorption and chemical adsorption to adsorb and eliminate toxic gas, and the physical adsorption is also called Van der Waals adsorption, which is caused by the action force between adsorbate and adsorbent molecules, and the force is also called Van der Waals force, which is the most common adsorption appearance, and is characterized in that the molecules of adsorbate are not attached to the fixed points on the surface of the adsorbent, but can slightly move at the interface. Because adsorption is caused by molecular force, the adsorption heat is small, and therefore, activation energy is not required, and the adsorption can be performed under low-temperature conditions. This adsorption is reversible and the molecules adsorbed together will also move away from the solid surface by sub-thermal movement, this appearance being called desorption. Physical adsorption can constitute a single-molecule adsorption layer or a multi-molecule adsorption layer, and one adsorbent can adsorb various substances because intermolecular forces are ubiquitous, but the amount of adsorption varies because of the nature of the adsorbate (solute). The adsorption appearance is closely related to the outer surface area and pore distribution of the adsorbent. Activated carbon is generally used for adsorbing toxic gases by physical adsorption. The active carbon is a carbonaceous adsorption material with rich pore structure and huge specific surface area, and the inside of the active carbon forms innumerable holes similar to molecular sieves, and as the inside of the holes is a place with unbalanced static electrodes, static unbalance is caused by surface action, the active carbon has strong adsorption force. Chemisorption is the adsorption in which adsorbate molecules undergo electron transfer, exchange or sharing with solid surface atoms (or molecules) to form adsorption chemical bonds. Because of the non-uniform force field on the solid surface, atoms on the surface often have residual bonding capability, and when gas molecules collide on the solid surface, electron exchange, transfer or sharing occurs between the atoms on the surface, so that adsorption of adsorption chemical bonds is formed. The chemical reaction between the chemisorbed adsorbent and the adsorbate (solute) takes place by the effect of chemical bonds, which results in a strong communication between the adsorbent and the adsorbate (solute). Because chemical reactions require much activation energy, it is generally desirable to operate at higher temperatures with greater heat of adsorption. Thus, chemisorption is a selective adsorption, i.e., an adsorbent has an adsorption effect on only a certain or a specific few substances. Because chemisorption is performed by direct chemical bond forces between the adsorbent and the adsorbate, chemisorption can only be formed as a single layer, adsorption is relatively stable and not easily desorbed, and chemisorption is directly related to the exterior chemistry of the adsorbent and to the chemistry of the adsorbate.

However, in the existing physical adsorption, the physical adsorption objects such as activated carbon are gaseous toxic substances, the energy of the toxic gas is relatively high, and once the physical adsorption conditions change, the toxic gas is easily desorbed and escapes. The existing chemisorption has the characteristics of environmental protection or uncleanness due to chemical reaction, and most of chemisorbed adsorbents cannot be reused, and the chemisorbed adsorbents are single substances and cannot adsorb a plurality of toxic substances at the same time.

Disclosure of Invention

The application provides a toxic gas adsorption device and a preparation method thereof, so that a plurality of toxic gases can be adsorbed simultaneously and can be reused.

In view of this, a first aspect of the present application provides a toxic gas adsorption device, the device comprising:

a silicon wafer;

the nanometer groove is arranged on the front surface of the silicon wafer, the concave depth of the nanometer groove is 2-8nm, and the diameter of the nanometer groove is 2-3 mu m;

and a glass substrate on which the back surface of the silicon wafer is bonded.

Preferably, the number of the nano grooves is multiple, and the nano grooves of two adjacent nano grooves are arranged on the front surface of the silicon wafer in parallel.

Preferably, the interval between adjacent nano grooves is 40-60 μm.

Preferably, the recess depth of two adjacent nano grooves is reduced by 0.1-4 nm.

Preferably, the silicon wafer is selected from N-type silicon wafers; the glass substrate is selected from high boric acid glass or microcrystalline glass.

Preferably, the nano grooves are formed on the front surface of the silicon wafer, specifically: the nano grooves are formed in the front surface of the silicon wafer through etching technology.

Preferably, the etching technique is a hydrofluoric acid wet etching technique.

Preferably, the back surface bonding of the silicon wafer on the glass substrate is specifically: the back surface of the silicon wafer is bonded to the glass substrate by electrostatic bonding techniques.

It should be noted that the processing method of the nano-groove in the toxic gas adsorption device of the present application may be various, and may be prepared by etching processing method, or may be prepared by other physical or chemical preparation methods.

The second aspect of the present application provides a specific preparation method of a toxic gas adsorption device, including the following steps:

step 1, etching the front surface of a silicon wafer into a nano groove by adopting an etching technology, wherein the recess depth of the nano groove is 2-8nm, and the diameter of the nano groove is 2-3 mu m;

and step 2, bonding the back surface of the silicon wafer with the glass substrate by adopting an electrostatic bonding technology to obtain the toxic gas adsorption device.

Preferably, the etching technology is specifically a hydrofluoric acid wet etching technology.

The toxic gas adsorption device can be used for adsorbing ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, carbon dioxide or hydrogen sulfide and other toxic gases.

From the above technical solutions, the embodiments of the present application have the following advantages:

the application has designed a poison gas adsorption equipment, the nanometer recess of this embodiment is the capillary passageway, when poison gas passes through the front of the silicon wafer of this embodiment, the medium can form a concave liquid level on the nanometer recess, the vapor pressure P that becomes balanced with this liquid level must be less than the saturated vapor pressure P0 of flat liquid level under the same temperature, when the diameter L3 of nanometer recess is the smaller, the radius of curvature of concave liquid level is the smaller, the vapor pressure P who balances rather than is the lower, consequently, when the diameter of nanometer recess is the smaller, can form the coacervate in the nanometer recess under lower P/P0 pressure. Along with the nano-groove being reduced to the nano-level and even being 3-7 times of the molecular kinetic radius of the gas, the gas can easily enter the nano-groove and liquefy, and the toxic gas adsorption device can be placed in a decompression chamber to enable the toxic gas to escape and further treat the toxic gas. The molecular kinematic radius of the toxic gas molecules is generally between 0.3 and 1nm, so that the recess depth of the nano groove is selected to be 2 to 8nm, so that the toxic gas adsorption device can condense and liquefy the toxic gas in the nano groove, the liquefied toxic gas is not easy to desorb and escape, other products are not generated by adopting the toxic gas adsorption device, and the silicon wafer and the glass substrate are high in stability, so that the toxic gas adsorption device can be reused.

Drawings

FIG. 1 is a top view of a toxic gas adsorbing device according to an embodiment of the present disclosure;

fig. 2 is a front view of a toxic gas adsorption device according to an embodiment of the present disclosure;

FIG. 3 is a first mask required for the hydrofluoric acid wet etching technique provided in the embodiments of the present application;

FIG. 4 is a schematic diagram of a one-time coated photoresist of a hydrofluoric acid wet etching technique provided in an embodiment of the present application;

FIG. 5 is a schematic illustration of a single exposure of a wet hydrofluoric acid etching technique according to embodiments of the present application;

FIG. 6 is a schematic diagram of a one-time hydrofluoric acid etch of a hydrofluoric acid wet etch technique provided by embodiments of the present application;

FIG. 7 is a schematic diagram of photoresist removal using a hydrofluoric acid wet etching technique according to embodiments of the present disclosure;

FIG. 8 is a second mask required for the hydrofluoric acid wet etching technique provided in embodiments of the present application;

FIG. 9 is a schematic diagram of a second-pass coated photoresist of a hydrofluoric acid wet etching technique provided in an embodiment of the present application;

FIG. 10 is a schematic diagram of a second exposure of a hydrofluoric acid wet etching technique provided in an embodiment of the present application;

FIG. 11 is a schematic diagram of a second hydrofluoric acid etch of a hydrofluoric acid wet etching technique provided by embodiments of the present application;

FIG. 12 is a schematic diagram of a silicon wafer after multiple photoresist coating, multiple exposure, multiple hydrofluoric acid etching and multiple photoresist removal in a hydrofluoric acid wet etching technique provided in embodiments of the present application;

fig. 13 is a schematic view of electrostatic bonding of a silicon wafer to a glass substrate according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the embodiments of the present application, are within the scope of the embodiments of the present application.

In the description of the embodiments of the present application, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on directions or positional relationships shown in the drawings, are merely for convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be configured and operated in the specific direction, and thus should not be construed as limiting the embodiments of the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in the embodiments of the present application will be understood by those of ordinary skill in the art in a specific context.

It should be understood that the present application is applied to the field of toxic gas adsorption, please refer to fig. 1-2, fig. 1 is a top view of a toxic gas adsorption device provided in an embodiment of the present application, fig. 2 is a front view of a toxic gas adsorption device provided in an embodiment of the present application, and as shown in fig. 1-2, the embodiment of the present application includes a silicon wafer 1; the nanometer groove 2 is arranged on the front surface of the silicon wafer 1, the concave depth H of the nanometer groove is 2-8nm, and the diameter L3 of the nanometer groove is 2-3 mu m; a glass substrate 3, and a back surface of the silicon wafer 1 is bonded to the glass substrate 3.

The application designs a poison gas adsorption device, the nano groove 2 of this embodiment is a capillary channel, when poison gas passes through the front of the silicon wafer 1 of this embodiment, the medium can form a concave liquid level on the nano groove 2, the vapor pressure P balanced with the liquid level must be less than the saturated vapor pressure P0 of the flat liquid level at the same temperature, when the diameter L3 of the nano groove is smaller, the smaller the radius of curvature of the concave liquid level is, the lower the vapor pressure P balanced with the nano groove is, therefore, when the diameter L3 of the nano groove is smaller, the medium can form condensed liquid in the nano groove 2 under the lower P/P0 pressure. Along with the nano-groove 2 being reduced to the nano-level and even being 3-7 times of the molecular kinetic radius of the gas, the gas can easily enter the nano-groove 2 and liquefy, and the toxic gas adsorption device can be placed in a decompression chamber to enable the toxic gas to escape and further treat the toxic gas. The molecular kinematic radius of poison gas molecules is generally between 0.3 and 1nm, so that the concave depth H of the nano groove is selected to be between 2 and 8nm, so that the poison gas adsorption device can condense and liquefy poison gas in the nano groove 2, and liquefied poison gas is not easy to desorb and escape.

The surface provided with the nano grooves 2 is the front surface of the silicon wafer, and the surface not provided with the nano grooves 2 is the back surface of the silicon wafer.

For easy understanding, referring to fig. 1-2, as shown in fig. 1-2, the number of nano grooves 2 in the present embodiment is plural, and two adjacent nano grooves 2 are parallel to each other and disposed on the front surface of the silicon wafer 1; the interval L2 between two adjacent nano grooves is 40-60 mu m. The directions of the parallel arrangement of the nano grooves 2 and the circulation of the toxic gas are the same, the toxic gas is more easily absorbed in the nano grooves 2, preferably, the nano grooves 2 of two adjacent nano grooves can be uniformly and mutually parallel arranged on the front surface of the silicon wafer 1, the nano grooves 2 of two adjacent nano grooves can also be actually needed, the non-uniform and mutually parallel arrangement is on the front surface of the silicon wafer 1, the nano grooves 2 can be more densely arranged on the silicon wafer 1 in a toxic gas dense area, and the nano grooves 2 can be non-densely arranged on the silicon wafer 1 in a toxic gas non-dense area.

For easy understanding, referring to fig. 1-2, as shown in fig. 1-2, the recess depth H of two adjacent nano-grooves in the present embodiment decreases with an equal difference of 0.1-4 nm. Because the molecular kinematic radiuses of different toxic gases are different, different toxic gases can be adsorbed by setting the concave depth H of different nano grooves.

Further, the silicon wafer 1 of the present embodiment is selected from N-type silicon wafers; the glass substrate 3 is selected from high boric acid glass or glass ceramics.

Further, the nano-grooves 2 of the present embodiment are disposed on the front surface of the silicon wafer 1 specifically: the nanometer groove 2 is arranged on the front surface of the silicon wafer 1 through etching technology; the back surface bonding of the silicon wafer 1 to the glass substrate 3 is specifically: the back surface of the silicon wafer 1 is bonded to the glass substrate 3 by electrostatic bonding technique.

Etching (etching technique) is performed to selectively etch or strip the surface of the substrate or the surface coating film according to the mask pattern or design requirements. Etching is classified into wet etching and dry etching. The present embodiment may select a hydrofluoric acid wet etching technique. Electrostatic bonding techniques are methods that can bond glass to metals, alloys, or semiconductors without any binder. The silicon wafer to be bonded is connected with the positive electrode of a power supply, the glass is connected with the negative electrode, and the voltage is 400V. The glass-silicon wafer was heated to 225 ℃. When a voltage is applied, na ions in the glass drift towards the negative electrode direction, a depletion layer is formed on the surface of the glass close to the silicon wafer, and the width of the depletion layer is about a few micrometers. The depletion layer has negative charge, the silicon chip has positive charge, and a large electrostatic attraction exists between the silicon chip and the glass, so that the silicon chip and the glass are in close contact.

Specifically, the etching technology and the electrostatic bonding technology are conventional technical means, and detailed descriptions thereof are omitted.

The embodiment of the application also provides a preparation method of the specific toxic gas adsorption device, which comprises the following steps:

step 1, etching the front surface of a silicon wafer 1 into a nano groove 2 by adopting an etching technology, wherein the recess depth H of the nano groove is 2-8nm, and the diameter L3 of the nano groove is 2-3 mu m;

and 2, bonding the back surface of the silicon wafer 1 with the glass substrate 3 by adopting an electrostatic bonding technology to obtain the toxic gas adsorption device.

Further, the etching technology of the present embodiment is specifically a hydrofluoric acid wet etching technology.

For ease of understanding, please refer to fig. 3-13, fig. 3 is a first mask required for the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 4 is a schematic view of a first coating photoresist of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 5 is a schematic view of a first exposure of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 6 is a schematic view of a first hydrofluoric acid etching of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 7 is a schematic view of photoresist removal of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 8 is a second mask required for the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 9 is a schematic view of a second coating photoresist of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 10 is a schematic view of a second exposure of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 11 is a schematic view of a second etching photoresist of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, fig. 12 is a schematic view of a wafer bonded to a wafer of the embodiment of the present application after a plurality of times of photoresist, exposure, etching and removal of the hydrofluoric acid wet etching technique provided in the embodiment of the present application, and a plurality of times is performed.

The embodiment of the application also provides a preparation method of the toxic gas adsorption device by adopting the hydrofluoric acid wet etching technology, which comprises the following steps:

step one, referring to fig. 3 and 8, preparing a plurality of masks (a first mask and a second mask) for wet etching of hydrofluoric acid according to need;

step two, referring to fig. 4, oxidizing the front surface of the silicon wafer 1 to form a silicon dioxide layer 6, and coating photoresist 7 on the silicon dioxide layer 6 of the silicon wafer 1 according to the pattern on the first mask;

step three, referring to fig. 5 to 6, performing one exposure treatment on the silicon wafer 1 coated with the photoresist 7 according to a standard photolithography process, wherein after exposure, the photoresist 6 forms a nano-groove 2, and the rest photoresist can be used as a mask for wet etching with hydrofluoric acid;

step four, referring to fig. 6, performing hydrofluoric acid wet etching on the front surface of the silicon wafer 1 in the step three to etch the silicon dioxide layer 6, so that the silicon dioxide layer 6 forms the nano grooves 2;

step five, referring to fig. 7, removing the photoresist 7 on the front surface of the silicon wafer 1 in step four, and oxidizing the front surface of the silicon wafer 1 to form a silicon dioxide layer 6;

step six, referring to fig. 9, photoresist 7 is coated on the front surface of the silicon wafer 1 in step five according to the pattern on the second mask;

step seven, referring to fig. 10, the silicon wafer 1 coated with the photoresist 7 is subjected to a secondary exposure treatment according to a standard photolithography process, after exposure, the photoresist 6 forms a nano-groove 2, and the rest of the photoresist can be used as a mask for wet etching with hydrofluoric acid;

step eight, referring to fig. 11, performing hydrofluoric acid wet etching on the front surface of the silicon wafer 1 in step seven to etch the silicon dioxide layer 6, so that the silicon dioxide layer 6 forms the nano grooves 2;

step nine, please refer to 12, repeating the steps of removing the photoresist 7 on the front surface of the silicon wafer 1 for multiple times, coating the photoresist 7 for multiple times, exposing for multiple times, and etching the silicon dioxide layer 6 by using hydrofluoric acid wet method for multiple times, so that the silicon wafer 1 forms nano grooves 2 with different lengths;

step ten, please refer to 13, bonding the silicon wafer 1 and the glass substrate 3 in step nine by electrostatic bonding technology to obtain the toxic gas adsorption device.

Specifically, in the first step, the mask is prepared by a conventional method, the mask is loaded with a design pattern, the micro-channels 5 with the width of 2 μm are designed on the mask 4, the distance between two adjacent micro-channels 5 is 40 μm, and the length of the micro-channels 5 is 40mm. The mask may be an N-type silicon wafer coated with a photoresist S1818, then uniformly coated to a thickness of 1.8 μm, then exposed, and then plasma-removed with a width of 2 μm and a length of 40mm, and the remaining photoresist may be used as a mask for HF acid wet etching.

Specifically, in the second step, the silicon wafer 1 may be an N-type silicon wafer or a similar silicon wafer. Photoresist S1818 may be selected as the photoresist 7 having a thickness of 1.8 μm.

Specifically, in the second step and the sixth step, the silicon dioxide layer 6 is formed by oxidizing the front surface of the silicon wafer 1 by a conventional method, the oxidation may be directly performed in an environment containing oxygen, or the silicon dioxide layer 6 may be formed by a thermal growth oxidation method, and the thickness of the silicon dioxide layer 6 is 1-2nm.

Specifically, in the fourth step, the eighth step and the ninth step, the dilution ratio of hydrofluoric acid is 100:1, hydrofluoric acid wet etching the silicon dioxide layer 6 to expose the micro-channel 5 of the silicon slice layer with the width of 2 μm and the length of 40mm.

Specifically, in the fifth and ninth steps, after wet etching with hydrofluoric acid, the photoresist 7 is heated to 70 ℃, and the photoresist 7 is dissolved and removed with the solvent 1165.

Specifically, after multiple hydrofluoric acid wet etching, nano grooves 2 with different depths can be prepared, wherein the depth H of the nano grooves 2 is related to the number n of hydrofluoric acid wet etching, where h=0.38+1.2×n, and the unit of H is nm.

Specifically, the hydrofluoric acid multiple wet etching method can be used for preparing the nano grooves 2 with the depths of 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm and the like on one N-type silicon wafer.

Specifically, the glass substrate of the embodiment of the application may be high boric acid glass with a thickness of 500 μm, a length of 45mm and a width of 50 mm.

Specifically, parameters of electrostatic bonding in the embodiment of the present application are: bonding is performed at 400v at 225 c, and electrostatic bonding at low temperature and low pressure can reduce deformation of the silicon wafer and also improve bonding quality.

The terms "first," "second," "third," "fourth," and the like in the description of the present application and in the above-described figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be capable of operation in sequences other than those illustrated or described herein, for example. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in this application, "at least one" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

The above embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. The preparation method of the toxic gas adsorption device is characterized by comprising the following steps of:

step 1, etching a nano groove on the front surface of a silicon wafer by adopting an etching technology, wherein the recess depth of the nano groove is 2-8nm, and the diameter of the nano groove is 2-3 mu m;

the number of the nano grooves is multiple, and the nano grooves of two adjacent nano grooves are mutually parallel and arranged on the front surface of the silicon wafer;

the concave depth of two adjacent nano grooves is decreased by 0.1 nm;

step 2, bonding the back surface of the silicon wafer with a glass substrate by adopting an electrostatic bonding technology to obtain a toxic gas adsorption device;

the back surface bonding of the silicon wafer on the glass substrate is specifically: the back of the silicon wafer is bonded on the glass substrate through an electrostatic bonding technology, the silicon wafer to be bonded is connected with the positive electrode of a power supply, the glass is connected with the negative electrode, and the glass-silicon wafer is heated.

2. The method of claim 1, wherein the etching technique is a hydrofluoric acid wet etching technique.

3. The preparation method according to claim 1, wherein the interval range of the adjacent two nano grooves is 40-60 μm.

4. The method of manufacturing according to claim 1, wherein the silicon wafer is selected from N-type silicon wafers; the glass substrate is selected from high boric acid glass or microcrystalline glass.