Nanostructured ZrO₂ Thin Films Deposited by Spray Pyrolysis Techniques for Ammonia Gas Sensing Application

Abstract

ABSTRACT. The spray pyrolysis deposition technique has number of advantages to produce advance nanostructured oxide films. The film surface morphology and structure depends on the precursor and doping solution and solvents used with their optimized parameters. The surface to volume ratio is achieved is beneficial to gas sensing. Therefore in this paper we report the nanostructured ZrO 2 thin films was prepared using spray pyrolysis technique for ammonia gas sensing. There is various precursors such as Zirconium acetylacetonate, Zirconium nitrate, Zirconium tetra chloride etc. In spite of them, the Zirconium oxychloride octohydrate (0.05 M) was chosen as precursor solution and was prepared by dissolving in pure distilled water (Solvent). The films were deposited on heated glass substrate at 350• C and were annealed at 500 • C for 1 hrs. It was characterized using XRD, FESEM, and TEM technique to examine crystal structure, surface morphology and microstructure properties. The average crystallite and grain size observed to be nanostructured in nature. The different test target gas performances were tested with various concentrations at different operating temperature. The films sprayed for 20 min with optimized spray parameter were observed to be most sensitive (S=58.5) to NH 3 for 500 ppm at 150 0 C. The film thickness dependence parameters: FWHM (0.02678 radians) for peak 111, Inter-planer distance (d=0.2958 nm), lattice parameters Inter-atomic spacing ( a=0.511 nm), atomic volume (a 3 = 133Å 3 ),micro strain (2.8 to 0.76 x 10 -2 ), crystallite size (4-5nm) average grain size (32nm), dislocation density (1.73 x10 15 lines/cm 2 ), texture coefficient (>1), specific surface area(31 m 2 /g), activation energy and band gap were studied. The sensor shows quick response (4 s) and fast recovery (10 s). Reported results are discussed and interpreted

Synthesis and structural evolution of partially and fully stabilized ZrO2 from a versatile method aided by microwave power

“…of Gd 3+ , only cubic ZrO 2 was obtained and the optical performance exhibited an intense UV emission up to 2.5% of Gd 3+ , whereas the red emission decreases with increasing Gd 3+ concentration. Stabilized zirconia can be obtained by several methods such as sol-gel [29][30][31][32][33], spray pyrolysis [34], co-precipitation [22,35], hydrothermal/solvothermal [8,20,36], electrochemical deposition [37] and combustion [23,26,38]. Nevertheless, most of these methods shows disadvantages related to the employed of high reaction temperatures, expensive processing techniques and long reaction times.…”

Studies on ZrO2 Thick and Thin Films: Structural, Morphological, Optical and Microstructure Behaviour

“…The observed band gaps are 4.67 and 4.8 eV for thick and thin film respectively. It is found that increase in band gap may be due to decrease in grain size [17][18][19][20][21][22][23]. Table 2 concludes that thin films are suitable for different application since it provides significant properties of thin films.…”

Effect of Cr on ZrO2 nanostructures for gas sensing investigation

“…At higher temperature that is [2300°C it has cubic structure, at intermediate temperature it has tetragonal structure and at low temperature that is\1100°C, it exists in monoclinic structure [15]. Recently, zirconia has created a great attention due to its supreme technological significance, because of its high refractive index, high thermal expansion coefficient, excellent oxygen ion conductivity, high dielectric constant, high corrosion resistance, high chemical stability, great toughness, microbial resistance [16][17][18][19][20][21][22][23][24], etc., which makes this SMO to emanate as an attractive material for massive functions in photonics, gas sensors, bio-sensor, thermal barrier coatings, fuel cells, dental medicine, buffer layer in high T c superconductors and so on [25][26][27][28][29][30][31]. The REDOX movement and the quality of high ionic exchange drive the metal as useful as catalyst [18].…”