Preparation and Characterization of Nanostructured Particulate Catalytic Materials
- PDF / 947,039 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 79 Downloads / 219 Views
Preparation and Characterization of Nanostructured Particulate Catalytic Materials Baiyun Tong1, Upali Siriwardane, Seetala V. Naidu2, Akundi N. Murty2, and Zhenchen Zhong2 Institute for Micromanufacturing (IfM) and Physics Program, Louisiana Tech University, Ruston, LA 71272, USA 1 Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110015, P. R. China 2 Department of Physics, Grambling State University1, Caver Hall Room 74, RWE Jones Dr., Grambling, LA 71245, USA ABSTRACT Laser Induced Solution Deposition (LISD) is essentially a laser chemical processing with similar mechanism of the counterpart - laser chemical vapor deposition (LCVD). It is a novel method for synthesizing nanocsale particles or thin films with the combined advantages of laser chemical vapor deposition and electroless chemical deposition in solution (electrolyte). It is simple and efficient, and it can produce high quality nanoparticles or patterned uniform thin films. In this paper the nanostructured Co/CoOx particles have been fabricated by LISD technique. We have characterized the deposited materials by using scanning electron microscope (SEM), the high-resolution transmission electron microscope (HRTEM) and X-ray diffraction technique (XRD). We have found that the sizes of the deposited particles are smaller than 5 nm uniformly suspended in the solution used in the LISD deposition, and the sizes are smaller than 500 nm on the silicon substrates inserted in the deposited solution. The results by energy dispersive X-ray analysis (EDX) have indicated that there are Co peaks and O peaks, which meant there were oxygen contamination or the deposited products were cobalt oxide rather than pure cobalt nanoparticles. The X-ray diffraction has shown that we have obtained pure Co nanoparticles in some cases but we have obtained cobalt oxides in other cases, which mainly depended on the experimental conditions such as the selection of solvents and solutes as well as the selection of the lasers including the wavelength and the power of the laser beams. The studies of the magnetic properties, catalytic properties as well as their relationship of pure cobalt nanoparticles and cobalt oxide nanoparticles are in good progress and we will publish the useful results elsewhere. INTRODUCTION Nanoscale and well-dispersed fine particle catalysts offer many advantages such as least diffusion resistance, easy accessibility to reactants, and large number of active sites. Since the efficient conversion of CO/CO2 gases to useful fuels is a major challenge facing scientific community, novel nano-particle catalysts seem to provide a promising alternative to conventional catalysts. Laser pyrolysis and photolysis are popular methods that have been used to prepare catalytic materials[1-5]. LISD offers several advantages over other methods because the deposition takes place in solution. All deposition experiments are carried out in the solutions of ammonia dissolved in distilled water or containing various mixtures of methanol, cyclohexane, W9.7.
Data Loading...
