Flexible sensor capable of detecting ammonia at normal temperature and preparation method thereof

Abstract

The invention relates to an ammonia sensor, in particular to a flexible sensor capable of detecting ammonia at normal temperature and a preparation method thereof. The flexible sensor provided by the invention employs photographic paper as a substrate, and has the characteristics of being capable of optionally folding, cutting and bending; an nano-silver layer dual-electrode-type electrode and an SWNT-PABS functional layer are prepared through painting on the protective film surface, including the photosensitive emulsion layer, of the photographic paper by the inkjet printing method; as the PABS has the characteristic of being very sensitive to ammonia, ammonia can be detected at normal temperature; the detection concentration can be as low as 1 ppm, so that the flexible sensor has the characteristic of sensitivity; the flexible sensor can keep good stability after being used for four months; and the preparation method of the flexible sensor is simple in process, can be miniature in size, and is easy to integrate.

Description

technical field [0001] The invention relates to an ammonia gas sensor, in particular to a flexible sensor for detecting ammonia gas at normal temperature and a preparation method thereof. Background technique [0002] Ammonia is a colorless and highly toxic gas, which can cause great harm to human health at low concentrations. Ammonia detection is widely used in many fields such as industry, medicine, refrigeration, agriculture, atmospheric detection, and national defense. . The ammonia gas sensor uses a substance that is highly sensitive to ammonia. A small change in the amount of ammonia will cause a large change in some physical or chemical properties of the substance (resistance, temperature, combustion point, optical properties, etc.). [0003] At present, the research and development of gas sensors is relatively rapid, and many methods have been used to prepare gas sensors, such as chemical vapor deposition (CVD), printing, coating, and electrospinning. However, the...

AI Technical Summary

Problems solved by technology

Titanium doped with In 2 o 3 The ammonia sensor made of ceramics can be prepared at a temperature of 145°C, and the sensitivity coefficient is not high enough

The Chinese patent No. CN 102103103A published on June 22, 2011 is a sensor for detecting ammonia and its preparation method, which uses P-type organic semiconductor poly(3-alkyl)thiophene as poly(3-hexyl) Thiophene is the raw material of the functional layer, which is prepared by oxidation and vacuum evaporation, which takes a long time to prepare and requires a higher temperature, and a higher temperature is required for detection

The Chinese patent No. CN 102636522A published on August 15, 2012 is a graphene / tin dioxide nanocomposite resistive thin-film gas sensor and its manufacturing method. It uses ceramics as the substrate and graphene / tin dioxide as the raw material. It can be detected at room temperature, but its application in many fields is limited due to its inflexibility.

But at the same time, the sensitivity of this ammonia sensor is relatively low due to its relatively low adsorption energy and binding force, and its selectivity is also relatively low.

Images