AVS 54th International Symposium | |
Applied Surface Science | Wednesday Sessions |
Session AS-WeM |
Session: | Chemical Imaging at High Spatial Resolution and Nanoscale Materials |
Presenter: | G.J. Exarhos, Pacific Northwest National Laboratory |
Authors: | G.J. Exarhos, Pacific Northwest National Laboratory Y. Shin, Pacific Northwest National Laboratory |
Correspondent: | Click to Email |
A form of nano-crystalline cellulose, isolated from carbohydrate-derived materials like paper or cotton, serves as a reducing template that drives formation of ordered regions of metal nanoparticles or nanorods when placed in aqueous metal precursor solutions under hydrothermal conditions. Uniform sized gold, silver, palladium, platinum, copper, nickel, selenium and other metal or metal-oxide nanocrystals were observed to rapidly nucleate and preferentially grow along the ordered hydroxyl-rich regions of the substrate. The ordered metals display catalytic, electrical and optical properties that would not normally be present in larger crystals. For example, a marked enhancement in the rate of degradation of organic dyes in water under uv-irradiation has been measured when selenium-decorated templates were immersed in methylene blue solutions. Materials have been characterized by means of XRD, FESEM, TEM, and optical methods. The mechanistics of the growth process will be discussed based upon these structural measurements and the known reducing properties of carbohydrate materials. Prospective uses of these materials for catalysis and in optical applications also will be described.