Understanding photo-conversion processes in chromophore - carbon nanotube nanohybrids
Abstract
Because of their unique one dimensional structure, large surface area, and electronic properties, single wall carbon nanotubes (SWCNTs) have been extensively studied for multiple applications, including electronics, biosensors, and solar energy harvesting. With charge separation ability and conductivity, semiconducting carbon nanotubes are applied as charge acceptors and structural frames in donor-acceptor solar cells. Herein, novel light harvesting nanohybrids in donor-acceptor systems are designed to study photo-conversion processes. DNA oligonucleotides with molecular recognition capabilities are used to tether charge donors (chromophores), while non-covalently adsorbing carbon nanotubes. Four types of porphyrin chromophores are studied for their optical electrochemical properties: singlet and triplet excited states, and redox potentials. These properties can directly affect the photo-conversion processes in nanohybrids. To understand the photo-conversion processes, steady state absorption and emission titration and excited state lifetime measurements are performed to understand the photo-conversion processes. Photo-induced charge transfer is observed in the nanohybrids. Deposited nanohybrid films are examined in a photoelectrochemical cell, and photocurrents are measured. Effects of electrolyte conditions on photocurrent are also studied.^
Degree
M.S.M.E.
Advisors
Jong Hyun Choi, Purdue University.
Subject Area
Engineering, Mechanical
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