CN-121703209-B - Transition metal doped ZnIn2S4Gas sensor and preparation method and application thereof

Abstract

The invention belongs to the technical field of new materials and electronic information, and particularly relates to a transition metal doped ZnIn 2 S 4 gas sensor, a preparation method and application thereof. The gas sensor comprises a substrate and a transition metal doped ZnIn 2 S 4 nano array which grows on the surface of the substrate in situ, wherein the nano array is composed of a plurality of two-dimensional nano sheets which are arranged in a staggered stacking mode and extend at an included angle of +/-5 degrees relative to the normal direction of the surface of the substrate, and a network assembly with a three-dimensional flower-shaped topological structure is formed through physical or chemical connection. The preparation method is simple, the energy band structure of the material is effectively regulated and controlled, the forbidden bandwidth is reduced, the specific surface area of the material is obviously increased, and the pore size distribution is optimized. The prepared gas sensor has excellent gas selectivity to triethylamine, high response value and high recovery speed, and is expected to be applied to the fields of environmental monitoring and food safety.

Inventors

• DUAN QIXI
• YANG YONG
• LIANG YAN
• SUN HAI

Assignees

• 江西师范大学

Dates

Publication Date

20260512

Application Date

20260211

Claims (4)

1. 1. The transition metal doped ZnIn 2 S 4 gas sensor comprises an Al 2 O 3 substrate and a Cu doped ZnIn 2 S 4 nano array which is grown on the surface of the substrate in situ by a one-step water bath method, and is characterized in that: The Cu-doped ZnIn 2 S 4 nano array forms an interface in atomic-level close contact with the Al 2 O 3 substrate, so that microcracks and interface contact resistance existing in a coating film layer are eliminated; The nano array is composed of a plurality of two-dimensional nano sheet layers, the two-dimensional nano sheet layers are arranged in a staggered stacking mode and extend at an included angle of +/-5 degrees relative to the normal direction of the surface of a substrate, the staggered angle between the adjacent sheet layers is 60 degrees or 80 degrees, and a network assembly with a three-dimensional flower-shaped topological structure is formed through physical or chemical connection, wherein the thickness of the two-dimensional nano sheet layers is 5 nm-20 nm, and the transverse dimension is 0.5-2 mu m; the doping amount of the Cu is 3 wt percent, and the Cu is embedded in the lattice structure of the ZnIn 2 S 4 in an atomic doping form; The specific surface area of the Cu-doped ZnIn 2 S 4 nano array is 168.98 m2/g, and the pore volume is 0.49 cm3/g; The response value of the gas sensor to the triethylamine gas with the concentration of 100 ppm at the working temperature of 250 ℃ is more than or equal to 85, the response time is less than or equal to 35 seconds, and the detection limit is less than or equal to 1ppm.
2. 2. A method of making the transition metal doped ZnIn 2 S 4 gas sensor of claim 1, characterized by in-situ growing a 3 wt% Cu doped ZnIn 2 S 4 nanoarray on a substrate surface using a one-step hydrothermal process, the method comprising: S1, uniformly mixing deionized water and glycerin according to a volume ratio of 20:3, adding nitric acid with a concentration of 1 mol/L to adjust the pH value of a system to 2.5, and carrying out ultrasonic dispersion treatment for 1 hour; S2, sequentially adding zinc chloride, indium chloride and thioacetamide, adding a copper source with a doping amount of 3 wt%, and stirring until the zinc chloride, the indium chloride and the thioacetamide are completely dissolved to form a uniform system, wherein the molar ratio of the zinc chloride to the thioacetamide is 1:2:2, the concentration of the zinc chloride is 6.65-mmol/L-11.74-mmol/L, the concentration of the indium chloride is 6.7-mmol/L-11.8-mmol/L, and the concentration of the thioacetamide is 13.3-mmol/L-23.5-mmol/L; And S3, mixing the solutions obtained in the step S1 and the step S2, placing the mixed solution into a closed reaction kettle, putting the Al 2 O 3 substrate subjected to surface cleaning treatment, reacting for 2 hours at 80 ℃ in a water bath heating mode, naturally cooling after the reaction is finished, taking out the substrate, washing the substrate by adopting deionized water and absolute ethyl alcohol in sequence, and drying for 4 to 12 hours at 60-80 ℃ to obtain the transition metal doped ZnIn 2 S 4 gas sensor.
3. 3. The method of claim 2, wherein the step of determining the position of the substrate comprises, The copper source is selected from copper chloride or copper nitrate.
4. 4. The use of the transition metal doped ZnIn 2 S 4 gas sensor according to claim 1 for detecting triethylamine gas.

Description

Transition metal doped ZnIn 2S4 gas sensor and preparation method and application thereof Technical Field The invention relates to the technical field of new materials and electronic information, in particular to a transition metal doped ZnIn 2S4 gas sensor, a preparation method and application thereof. Background With the acceleration of modern industrialization processes and the frequent human activities, atmospheric environmental pollution has become a global focus of attention. Among the numerous contaminants, volatile Organic Compounds (VOCs) are valued for their wide sources, complex composition and great hazard. Triethylamine is used as a typical aliphatic amine VOCs and is widely applied to the industries of chemical synthesis, preservative manufacturing, seafood processing and the like. However, triethylamine has strong pungent smell and remarkable biotoxicity, and short-term exposure to low-concentration triethylamine can lead to strong stimulation of conjunctiva and respiratory system of eyes of a human body, and long-term exposure can even cause pulmonary edema and cornea injury. In addition, triethylamine is also an important component of volatile basic nitrogen released during the spoilage of protein-rich foods (e.g., seafood, meat). Therefore, the development of the triethylamine gas sensor which can be used for real-time, rapid and high-sensitivity and has excellent selectivity has extremely important practical significance in the fields of environmental air quality monitoring, industrial production safety precaution and food freshness evaluation. Currently, gas sensor technologies for detecting triethylamine mainly use Metal Oxide Semiconductor (MOS) materials, such as tin dioxide, zinc oxide, tungsten oxide, and the like. Such sensors are dominant in commercial applications by virtue of their low cost of production, simple circuit design, and the like. However, most of the conventional mos sensors have a bottleneck problem of high operating temperature, high power consumption, sensitivity to environmental humidity, and poor selectivity. The high-temperature working environment not only increases the energy consumption, but also can cause the potential safety hazard of inflammable and explosive gas, and accelerates the grain growth and aging of sensitive materials, thereby reducing the long-term stability of the sensor. In contrast, ternary metal sulfides (such as ZnIn 2S4) as a narrow bandgap semiconductor material with visible light response have attracted considerable attention in the field of gas sensing due to their unique layered crystal structure, abundant surface active sites and good chemical stability. Although pure ZnIn 2S4 materials exhibit a certain gas-sensitive potential, there are still some bottleneck problems that limit their practical application properties. First, the intrinsic carrier concentration of pure ZnIn 2S4 is low, the forbidden bandwidth is wide, resulting in poor conductivity at low temperature and large baseline resistance. Secondly, the density of active sites on the surface of the unmodified material is insufficient, the adsorption energy of target gas molecules is low, and the improvement of sensitivity is limited. Furthermore, conventional gas sensor manufacturing processes typically involve powder material synthesis, slurry formulation, and coating processes. The ex-situ preparation method enables the sensitive film layer to be in loose contact with the substrate, the interface contact resistance is large, and the film layer is easy to peel off in the use process, so that the consistency and long-term stability of the device are poor. To overcome the above drawbacks, elemental doping and device structure modulation are considered effective modification strategies. Cu is used as an important transition metal element, the ionic radius of the Cu is similar to that of zinc ions, and lattice substitution doping is easy to realize. Theory and experiment show that Cu doping can introduce impurity level into ZnIn 2S4, regulate and control energy band structure, reduce forbidden bandwidth and raise conductivity of material. Meanwhile, lattice distortion caused by doping can generate abundant defects such as sulfur vacancies and the like, and the defects are expected to become active centers for gas adsorption. In addition, the in-situ growth technology can enable the sensitive material to directly nucleate and grow on the surface of the electrode to form a nano array structure which is orderly arranged and firmly combined, so that the problem of poor interface contact is effectively solved, and a three-dimensional pore network structure with a large specific surface area, which is favorable for gas diffusion, is provided. However, the in-situ growth of Cu-doped ZnIn 2S4 nano-chip array and the application thereof in triethylamine detection are not reported at present, and particularly, the in-depth research of combining the energy band structure evolution and the