Conceptual model for spray pyrolysis mechanism: fabrication and annealing of titania thin films

Abstract

The present work presents a comprehensive model of both processes and outcomes of the spray pyrolysis mechanism, which is based on wide-ranging experience gained from experimentation involving a range of parameters. The deposition temperature and initial droplet size are the main parameters controlling film properties, including mineralogy, surface morphology, thickness, and bonding; the effect of annealing on these properties also is considered. The model is supported experimentally through the processing of films aerosol and ultrasonically spray pyrolyzed at 350°C, followed by annealing for 12 h at 500°C in air. Assessment of the mineralogy, chemical bonding, and crystallinity/residual stress of the films involved glancing-angle X-ray diffraction and laser Raman microspectroscopy, Fourier transform infrared spectroscopy, and crossed polarizers with an optical microscope, respectively.

Thin Films for Immobilization of Complexes with Optical Properties

“…The substrate surface temperature is a parameter that determines the film morphology and properties so that by increasing the temperature, the film morphology can be changed from a cracked to a porous microstructure [1]. The influence of different parameters on the thickness, morphology, crystal structure, and adhesion of the films is discussed in [5,67], and optimal values are given (in brackets) for the nature of the carrier gas (oxygen or nitrogen) and its flow rate (0.5-1.2 dm 3 / min), the substrate temperature during the spraying (350°C or 400°C), the spraying angle (varied in the interval 20°-90°), the distance between the substrate and the nozzle (15-25 cm), the duration of spraying (10-20 s), the interval between the consecutive sprayings (1-5 min), the number of sprayings (1-20 cycles), the postdeposition annealing temperature (350-480°C), and the type of substrate. A comprehensive model for spray pyrolysis using solutions is presented in [67].…”

“…The influence of different parameters on the thickness, morphology, crystal structure, and adhesion of the films is discussed in [5,67], and optimal values are given (in brackets) for the nature of the carrier gas (oxygen or nitrogen) and its flow rate (0.5-1.2 dm 3 / min), the substrate temperature during the spraying (350°C or 400°C), the spraying angle (varied in the interval 20°-90°), the distance between the substrate and the nozzle (15-25 cm), the duration of spraying (10-20 s), the interval between the consecutive sprayings (1-5 min), the number of sprayings (1-20 cycles), the postdeposition annealing temperature (350-480°C), and the type of substrate. A comprehensive model for spray pyrolysis using solutions is presented in [67]. Different solutions or suspensions have been used such as ethylene glycol solution of mixed metal citrate complexes [67,68] and aqueous or methanol suspensions containing TiO 2 and EG or PEG [54].…”

“…A comprehensive model for spray pyrolysis using solutions is presented in [67]. Different solutions or suspensions have been used such as ethylene glycol solution of mixed metal citrate complexes [67,68] and aqueous or methanol suspensions containing TiO 2 and EG or PEG [54]. In some of the experiments, sonication for 20 min by means of ultrasonic disintegrator, UD, 20 (Technopan, Poland) was applied before spraying [54].…”

Low temperature synthesis by spray pyrolysis of La0.9Sr0.1Co0.2Fe0.8O3 thin films using ethanol and water as a solvent and their microstructural characterization

“…Thin films are present in electronic materials [1], solar cells [2], sensors, coatings, superconductors [3,4], semiconductors [4,5], and fuel cells [6][7][8]. The use and application of thin films makes the work with low weight equipment possible, providing a higher return in the manufacturing process.…”

Electrochemical Performance of a Ni and YSZ Composite Synthesised by Ultrasonic Spray Pyrolysis as an Anode for SOFCs

“…Among those, SP is known to be an appropriate method for engineering the morphology and composition of particles because it integrates the evaporation, precipitation, decomposition and sintering stages of powder synthesis into a single continuous process [11]. It also has many advantages, such as low operational costs, simple facilities, ambient operation and the potential for mass production [12]. Thus, it has often been employed to synthesise functional nanostructured composites for the anode of SOFC.…”