Silver (Ag) nanolayers were deposited on nickel oxide (NiO) thin films by DC magnetron sputtering. The thickness of Ag layers was in range of 20-80 nm by variation of deposition time between 10 and 40 s. X-ray diffraction results showed that the crystalline properties of the Ag/NiO films improved by increasing the Ag film thickness. Also, atomic force microscopy and field emission scanning electron microscopy images demonstrated that the surface morphology of the films was highly affected by film thickness. The film thickness and the size of particles change by elevating the Ag deposition times. The composition of films was determined by Rutherford back scattering spectroscopy. The transmission of light was gradually reduced by augmentation of Ag films thickness. Furthermore; the optical band gap of the films was also calculated from the transmittance spectra.
Considering studies done on the result of methanol conversion over SAP-34 molecular sieve, it is understood that increase of selectivity is ascribed to the increase of acidity in acid sites which is a result of incorporation of metal in crystal structure and decrease of crystal size. In this study, metal incorporation in the SAPO-34 structure leaded to increase of acid sites concentration but did not affect the acid strength distribution. The catalytic performance of the SAPO-34 nanoparticles in the MTO reaction varied according to their crystallite size. Decreasing particle size results in larger increase of external surface area and shorter diffusion path, both cause reduction in mass and heat transfer resistances in catalysis and sorption. In this work a rapid high-temperature synthesis method was developed to synthesis uniform nanoparticles of SAPO 34 zeolite with high crystallinity and metal was successfully incorporated in crystal structure. In order to investigate the effects of temperature and synthesis time on purity and crystallinity of the synthesized samples, the crystallization temperature was increased from 350 to 550 K while the synthesis time was decreased from 24 h to 45 min. The samples were characterized by XRD, BET and SEM analysis techniques. It was found that by using high temperature and short synthesis time the particle size decreased and the metal was properly incorporated into the crystal structure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.