PhD Candidate Wins First Prize for Spectroscopic and Computational Study
Tao Chen, a PhD candidate from the Chemical Engineering & Materials Science Department at Stevens Institute of Technology (Hoboken, New Jersey), has won the first prize and a cash award for his research presentation at the annual symposium of the Catalysis Society of Metropolitan New York.
Tao Chen, a PhD candidate from the Chemical Engineering & Materials Science Department at Stevens Institute of Technology (Hoboken, New Jersey), has won the first prize and a cash award for his research presentation at the annual symposium of the Catalysis Society of Metropolitan New York. Chen's winning presentation was titled “Spectroscopic and computational study of BPE adsorption on Ag/SiO2 as a function of silver oxidation and adsorbate coverage.” He is co-advised in his research by Stevens professors, Simon Podkolzin and Henry Du.
In Tao’s project, monodispersed silver nanoparticles with a diameter of about 50 nanometers supported on silica were synthesized using a colloidal solution. The extent of silver oxidation was varied with a time-controlled exposure to ozone and monitored with X-ray photoelectron spectroscopic measurements. Vibrational spectra were collected using surface-enhanced Raman spectroscopy. Adsorption geometries and vibrational modes were analyzed with quantum chemical calculations using density functional theory. This closely integrated experimental and theoretical study for the first time identified at the molecular level the adsorption modes and energetics of an organic probe molecule trans-1,2-bis(4-pyridyl)ethylene (BPE) on silver nanoparticles. In addition, effects of the adsorbate coverage and the extent of silver oxidation were evaluated. This understanding will help scientists to choose optimal conditions for running chemical reactions with catalytic silver nanoparticles and also to improve sensors that use similar nanoparticles as spectroscopic detectors.
The symposium was held on March 14, 2012 at the ExxonMobil Corporate Research in Annandale, NJ and was attended by more than 130 participants. Students and postdoctoral researchers participated in a poster competition with 30 poster presentations from universities in New York, New Jersey, Pennsylvania, and Delaware.
Getting accurate IR spectra on monolayer of molecules
April 18th 2024Creating uniform and repeatable monolayers is incredibly important for both scientific pursuits as well as the manufacturing of products in semiconductor, biotechnology, and. other industries. However, measuring monolayers and functionalized surfaces directly is. difficult, and many rely on a variety of characterization techniques that when used together can provide some degree of confidence. By combining non-contact atomic force microscopy (AFM) and IR spectroscopy, IR PiFM provides sensitive and accurate analysis of sub-monolayer of molecules without the concern of tip-sample cross contamination. Dr. Sung Park, Molecular Vista, joined Spectroscopy to provide insights on how IR PiFM can acquire IR signature of monolayer films due to its unique implementation.
Deep Level Transient Spectroscopy Reveals Influence of Defects on 2D Semiconductor Devices
April 25th 2024A recent study used deep level transient spectroscopy to investigate the electrical response of defect filling and emission in monolayer metal-organic chemical vapor deposition (MOCVD)-grown materials deposited on complementary metal-oxide-semiconductor (CMOS)-compatible substrates.
