|Photocatalysis||Electrocatalysis||Heterogeneous Catalysis||Laboratory Resources|
In the ever-expanding field of photocatalysis, our group places an emphasis on gaining a thorough understanding of the mechanisms involved in heterogeneous photocatalytic systems at the molecular level. Our approach combines the results of kinetic studies with rigorous in-situ and ex-situ catalyst characterization as well as computational modeling of these systems.
Our lab was one of the first to report and explain the mechanisms behind the use of plasmonic metal nanoparticles (Ag, Au, and Cu) as a driver for photocatalytic enhancement on both semiconductors and directly on plasmonic metals. The unique dielectric properties of plasmonic metal nanoparticles allow them to focus incoming electromagnetic radiation (i.e. light) directly onto the surface of catalyst particles, where chemical transformations occur. By doing so, these catalysts are able to efficiently convert visible light into chemical energy that can be used to drive chemical reactions. Experimentally our group has used plasmonic metal nanoparticles to enhance reaction rates and selectivities for industrially important reactions. We are now working on new catalysts that combine multiple metals to broaden the applications of plasmonic catalysts. We have also coupled plasmonic metals with semiconducters in photoelectrochemical systems to improve the efficiency of processes such as hydrogen evolution. Current members working in this area include Umar Aslam, Joseph Quinn, Steven Chavez, and John Hemmerling.
Currently, the complex mechanisms that cause photocatalytic enhancement on plasmonic metal nanoparticle systems are not fully understood. Our group combines experimental characterization studies with computational modeling to gain insight into these mechanisms at the molecular level. Techniques such as in situ UV-visible and Raman spectroscopy allow us to monitor the optical properties of catalysts and how they may change in response to exposure to light or the introduction of reactants. Our group's dedicated computing cluster allows us to perform complex DFT (density functional theory) and FDTD (finite difference time domain) model calculations of the catalyst systems we seek to understand. In combination, these experimental and computational results have continued to shed light on many of the important mechanistic aspects of plasmonic photocatalysts, which in turn leads to better catalyst and reaction system design and implementation. Current members working in this area include Vishal Govind Rao, Umar Aslam, Steven Chavez and Rachel Elias.
Addressing challenges and scalability in the synthesis of thin uniform metal shells on
large metal nanoparticle cores: Case study of Ag-Pt core-shell nanocubes
U. Aslam and S. Linic, ACS Applied Materials & Interfaces, 9, 43127, 2017.
Controlling energy flow in multimetallic nanostructures for plasmonic catalysis
U. Aslam, S. Chavez, S. Linic, Nature Nanotechnology, 12, 1000, 2017.
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Engineering the Optical and Catalytic Properties of Co-Catalyst/Semiconductor Photocatalysts
P. Hernley, S. Chavez, J. Quinn, S. Linic, ACS Photonics, 4, 979, 2017.
Kinetic Trapping of Immiscible Metal Atoms into Bimetallic Nanoparticles through Plasmonic Visible
Light-Mediated Reduction of a Bimetallic Oxide Precursor: Case Study of Ag-Pt Nanoparticle Synthesis
U. Aslam, S. Linic, Chem. Mater., 28, 8289, 2016.
Mechanism of Charge Transfer from Plasmonic Nanostructures to Chemically Attached Materials
C. Boerigter, U. Aslam, S. Linic, ACS Nano, 10, 6108, 2016.
Evidence and implications of direct charge excitation as the dominant mechanism
in plasmon-mediated photocatalysis.
C. Boerigter, R. Campana, M. Morabito, S. Linic, Nature Communications, 7, 10545, 2016.
Photo-chemical transformations on plasmonic metal nanoparticles
S. Linic, U. Aslam, C. Boerigter, M. Morabito, Nature Materials, 14, 567, 2015.
Catalytic and Photocatalytic Transformations on Metal Nanoparticles with
Targeted Geometric and Plasmonic Properties
S. Linic, P. Christopher, M. Andiappan, H. Xin, Accounts of Chemical Research, 46, 1890, 2013.
Tuning selectivity in propylene epoxidation by plasmon mediated photo-switching
of Cu oxidation state
M. Andiappan, J. Zhang, S. Linic, Science, 339, 1590, 2013.
Singular Characteristics and Unique Chemical Bond Activation Mechanisms of
Photocatalytic Reactions on Plasmonic Nanostructures
P. Christopher, H. Xin, M. Andiappan, S. Linic, Nature Materials, 11, 1044, 2012.
Design of Plasmonic Platforms for Selective Molecular Sensing Based on Surface
Enhanced Raman Spectroscopy
M. Andiappan, P. Christopher, S. Linic, J. Phys. Chem. C, 116, 9824, 2012.
Plasmonic-metal nanostructures for efficient conversion of solar to chemical energy
S. Linic, P. Christopher, D. B. Ingram, Nature Materials, 10, 911, 2011.
Predictive model for the design of plasmonic metal/semiconductor composite
D. B. Ingram, P. Christopher, J. Bauer, S. Linic, ACS Catalysis, 1, 1441, 2011.
Visible light enhanced catalytic oxidation reactions on plasmonic silver nanostructures
P. Christopher, H. Xin, S. Linic, Nature Chemistry, 3, 467, 2011.
Water splitting on composite plasmonic-metal/semiconductor photo-electrodes:
Evidence for selective plasmon induced formation of charge carriers
D. B. Ingram, S. Linic, JACS, 133, 5202, 2011.
Enhancing photo-chemical activity of semiconductor nanoparticles with optically
active Ag nano-structures: Photo-chemistry mediated by Ag surface plasmons
P. Christopher, D. B. Ingram, S. Linic, J. Phys. Chem. C, 114, 9173, 2010.