Tungstic oxide nano-wire and method for preparing tungstic oxide nano-wire ammonia sensitive sensor

Abstract

The invention relates to a tungsten oxide nano-wire ammonia-sensitive sensor and a preparation method thereof, belonging to the gas sensor technical field. The method comprises the following steps that: sodium tungstate is dissolved in deionized water to prepare a sodium tungstate solution; a hydrochloric acid and an oxalic acid are dripped slowly and stirred; a flaxen micellar solution is transferred into a reaction kettle, added with 25 to 30 grams of potassium sulfate and uniformly stirred, and the mixture undergoes hydrothermal treatment for 12 to 144 hours at a temperature of 180 DEG C; hydrothermal products are washed and fully dried in the presence of air with a temperature of 65 DEG C, and then a tungsten oxide nano-wire is prepared; adhesives and frit are added according to the tungsten oxide nano-wire prepared to prepare gas-sensitive materials slurry; and then the tungsten oxide nano-wire ammonia-sensitive sensor is prepared after element sintering and ageing. The method has simple steps, easily controlled parameters, and low energy consumption during the whole preparation process; the tungsten oxide nano-wire prepared has a large specific surface area; and the tungsten oxide nano-wire ammonia-sensitive sensor prepared has high sensitivity on low-concentration ammonia (between 1 and 100 pars per million), good repeatability and high stability.

Description

technical field [0001] The invention relates to a preparation method of a tungsten oxide nanowire and an ammonia-sensitive sensor of the tungsten oxide nanowire, belonging to the technical field of gas-sensitive sensors. Background technique [0002] Tungsten oxide is a transition metal oxide n-type semiconductor. As a functional material, in recent years, a large number of studies have found that tungsten-based oxides are not only used as catalysis, electrochromism, battery electrodes, solar energy absorbing materials and stealth materials, but also semiconductor functional materials such as heat-sensitive, pressure-sensitive and gas-sensitive. The characteristics of tungsten oxide nanocrystalline film in gas sensor, photocatalysis, photoconductivity and other aspects of the application and research are attracting more and more people's attention, especially in the application field of oxide semiconductor gas sensor, tungsten oxide base materials have been considered to de...

AI Technical Summary

Problems solved by technology

However, the results show that the nanowire network structure with 30ppm NH 3 There is no obvious response in the temperature range of 200-500°C, and the nanowire needs to be prepared at a high temperature of 1400-1450°C, and the sensitive film needs up to 6 days of long-term annealing to obtain stable electrical properties, resulting in huge energy consumption

In summary, most of the current research on tungsten oxide-based sensors is mainly focused on the research of polycrystalline films composed of large grain sizes. Due to the limitations of the surface structure and grain size, the sensitivity and selectivity of the sensors are not ideal. Only by improving High sensitivity and repeatability can only be obtained when testing temperature or by doping other materials

At present, only a few reports at home and abroad involve the research on tungsten oxide nanowire sensors, and all of them have the following deficiencies to varying degrees: the preparation process of tungsten oxide nanowires is very complicated; the raw materials are expensive; the precursor needs high temperature treatment; The film forming cycle is long; it is very difficult to obtain a sensitive film with good sensitivity and stable gas sensitivity

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