Preparation Of Flower Like Zinc Oxide And Its Applications In The Detection Of Explosives

In recent years, the detection of explosives and explosive compounds has become a highly concerned issue in the field of safeguarding homeland security and the fight against terrorism. So the explosive detection plays an important role in the maintenance of national security and counterterrorism riot. At present, the research of explosive detection is mainly concentrated in the standard explosive, a lack of systematic research on the detection of the non-standard explosive usually used in the terrorist. The gas sensor based on nano-material has a advantages of small size, low energy consumption, high sensitivity, fast response and so on, which plays an important role in the detection of trace amounts of standard and non-standard explosive.Next, the performance of various aspects of flower- like Zinc Oxide and Zinc Oxide nanocrystals is compared. The structural properties of the two samples were analyzed by X-ray diffraction(XRD), and the morphology characteristics of the two samples were observed and analyzed by scanning electron microscope(SEM). Then, the photocurrent of two samples under UV light irradiation were measured, finding that the flower like Zn O photocurrent signal is much higher than that of zinc oxide nanocrystals, for that oxygen vacancies and oxygen chemisorption is the key factor affecting the magnitude of photocurrent.At the same time, the light current characteristics of the flower like Zinc Oxide have been tested under different explosive atmospheres. The analysis shows that the oxygen in the gas can obtain electrons from the explosive atmospheres and the gained electrons O2- can lost electrons to be oxygen. Thus, the change in the width of depletion layer of Zinc Oxide which depends on the ability of Zinc Oxide gaining or losing electrons from the gas. Based on this, we developed flower-like Zn O photoelectric gas sensor, and it was used to detect organic standard explosives: 2,4,6-trinitrotoluene(TNT), 2, 4-Dinitrotoluene(DNT), para-nitro toluene(PNT), picric acid(PA).In addition, we have also developed Mn-doped Zn O sensors array, and it was used to detect a variety of standard and non-standard explosives, including TNT, DNT, PA, PNT, S, ammonium nitrate(AN), black powder(BP), potassium permanganate(PP), potassium nitrate(PN) and potassium chlorate(PC). The sensor array, which is composed of a plurality of sensors, has great potential to develop because of the simple fabrication, miniaturization and portability of integrated electronic circuits. We have produced Zinc Oxide array with different Mn content, which has a better performance than a single sensor. The next step, a more general, simple and sensitive sensor system for the detection of explosives in the actual complex environmental system will be to construct.