Alex Mobashery, a Penn High School, Mishawaka student carried out research in the Kamat laboratory for the past two years (his junior and senior year). Recently, he participated in the Intel International Science and Engineering Fair 2013.

His Project "Boosting Current of Quantum Dot Sensitized Solar Cells with CdS/PbS Heterostructures" placed fourth in the Energy and Transportation category of the Grand Award Winner.

Join us in congratulating Alex on his great work in our lab and awesome showing at the Science and Engineering Fair!

James Radich, a graduate student in our lab, was recently awarded two fellowships that allow him to explore his own proposed research topics: the Eiler's Sustainable Energy Research Fellowship and the Bayer Environmental Research Fellowship. The energy research will focus on the incorporation of copper-based p-type nanocrystals into solid state quantum dot solar cells. The environmental research pivots from a recent publication on Holey Graphene and aims to understand the fate of graphene and other carbon nanomaterials in oxidative environments. Congratulations to James for these awards!

Watch this webinar the formation of holes in graphene due to gold-nanoparticle-mediated attack of the reduced graphene oxide sheet by hydroxyl radicals. This webinar is based off of the paper, recently published in ACS Nano, entitled:

Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) have important applications in the development of new electrode and photocatalyst architectures. Gold nanoparticles (AuNPs) have now been employed as catalyst to generate OH^• and oxidize RGO via hydroxyl radical attack. The oxidation of RGO is marked by pores and wrinkles within the 2-D network. Nanosecond laser flash photolysis was used in conjunction with competition kinetics to elucidate the oxidative mechanism and calculate rate constants for the AuNP-catalyzed and direct reaction between RGO and OH^•. The results highlight the use of the AuNP-mediated oxidation reaction to tune the properties of RGO through the degree of oxidation and/or functional group selectivity in addition to the nanoporous and wrinkle facets. The ability of AuNPs to catalyze the photolytic decomposition of H₂O₂ as well as the hydroxyl radical-induced oxidation of RGO raises new issues concerning graphene stability in energy conversion and storage (photocatalysis, fuel cells, Li-ion batteries, etc.). Understanding RGO oxidation by free radicals will aid in maintaining the long-term stability of RGO-based functional composites where intimate contact with radical species is inevitable.

Watch this webinar on how to promote galvinic exchange on the surface of reduced graphene oxide for the design of new catalyst materials. This webinar is based off of the paper, published in the Journal of Physical Chemistry C, entitled:

Abstract: The two-dimensional network of reduced graphene oxide (RGO) is decorated with silver and gold nanoparticles. The silver nanoparticles deposited on RGO by photocatalytic reduction are subjected to galvanic exchange with Au³⁺ ions to transform them into gold nanoparticles. This compositional change on the RGO surface demonstrates RGO's versatile ability to anchor a wide array of nano-particles and facilitate chemical transformations. Coupled with RGO's unique ability to capture and transport electrons, galvanic exchange is used to contrive a two-dimensional nano catalyst mat. Raman studies show that metal nanoparticles anchored on reduced graphene oxide facilitate enhancement of Raman bands. Using methyl viologen as a probe we elucidate the photocatalytic activity of the Semiconductor-RGO-Metal nanoassembly and highlight the mediation of RGO in charge transfer processes.

Read the latest paper from the Kamat Lab!

Making Graphene Holey. Gold-Nanoparticle-Mediated Hydroxyl Radical Attack on Reduced Graphene Oxide

Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) have important applications in the development of new electrode and photocatalyst architectures. Gold nanoparticles (AuNPs) have now been employed as catalyst to generate OH^• and oxidize RGO via hydroxyl radical attack. The oxidation of RGO is marked by pores and wrinkles within the 2-D network. Nanosecond laser flash photolysis was used in conjunction with competition kinetics to elucidate the oxidative mechanism and calculate rate constants for the AuNP-catalyzed and direct reaction between RGO and OH^•. The results highlight the use of the AuNP-mediated oxidation reaction to tune the properties of RGO through the degree of oxidation and/or functional group selectivity in addition to the nanoporous and wrinkle facets. The ability of AuNPs to catalyze the photolytic decomposition of H₂O₂ as well as the hydroxyl radical-induced oxidation of RGO raises new issues concerning graphene stability in energy conversion and storage (photocatalysis, fuel cells, Li-ion batteries, etc.). Understanding RGO oxidation by free radicals will aid in maintaining the long-term stability of RGO-based functional composites where intimate contact with radical species is inevitable.

Read the latest paper from the Kamat Lab!

Improved Performance of CdSe Nanowire Solar Cells using Carbazole as Surface Modifier.

Abstract: Carbazole molecules containing thiol functional groups, when attached to CdSe nanowires (NWs), facilitate hole transport across semiconductor interfaces. The improved hole transfer rate is evidenced by increased electron lifetimes and better photovoltaic performance. Nanowire solar cells (NWSCs) with carbazole treatment delivered a power conversion efficiency of 0.46%, which is an order of magnitude improvement over untreated films. The illumination of the sample during the electrophoretic deposition of nanowires also had a profound effect in obtaining stable and higher photocurrents.

Congratulations to Dr. Sean Murphy on successful completion of his Ph. D. in Chemistry! Sean successfully defended his doctoral thesis entitled:

Metal Nanoparticle-Graphene Oxide Composites: Photophysical Properties and Sensing Applications.

Congratulations on completion of your Ph. D. Sean!