Occidental College




A Study of Pt-Sn Nanoparticles by Scanning Tunneling Microscopy (STM)
and Ultraviolet-visible (UV-vis) Absorption

Christian Hernandez
Project Advisor: Adrian Hightower     

      This study focused on visually and electrochemically characterizing tin (Sn), and platinum (Pt) nanoparticles by Scanning Tunneling Microscopy and UV-Absorption. The purpose of this study was to analyze the correlation between the distribution of nanoparticles in a given area and the amount of time spent waiting for an initial reaction to occur after adding our reducing agent sodium borohydride. Pt and Sn nanoparticles were synthesized, purified, cleaned, and deposited onto a graphite surface to characterize the surface nanostructure using STM. Samples of Pt and Sn nanoparticle solution were also analyzed using UV-vis absorption to properly depict at what point in time the metal in the solution will drop down to a ground state where no absorption would occur, signaling the completion of an initial reaction. Together STM and UV-vis absorption were used to determine the particle size distribution and its relationship to time associated with the synthesis.

Support provided by:  Ford Research Endowment

Undergraduate Research Center 1600 Campus Rd. Los Angeles, CA. 90041 (323) 259-1414