@article{lynch_kelliher_anderson_japit_spencer_rizvi_sarac_augustyn_tracy_2021, title={Sulfidation and selenidation of nickel nanoparticles}, volume={3}, ISSN={["2637-9368"]}, url={https://doi.org/10.1002/cey2.83}, DOI={10.1002/cey2.83}, abstractNote={Transition metal chalcogenide nanoparticles (NPs) are of interest for energy applications, including batteries, supercapacitors, and electrocatalysis. Many methods have been established for synthesizing Ni NPs, and conversion chemistry to form Ni oxide and phosphides from template Ni NPs is well-understood. Sulfidation and selenidation of Ni NPs have been much less explored, however. We report a method for the conversion of Ni template NPs into sulfide and selenide product NPs using elemental sulfur, 1-hexadecanthiol, thiourea, trioctylphosphine sulfide, elemental selenium, and selenourea. While maintaining mole ratios of 2 mmol sulfur/selenium precursor: mmol Ni, products with phases of Ni3S2, Ni9S8, NiS, NiSO4·6H2O, Ni3S4, Ni3Se2, and NiSe have been obtained. The products have voids that form through the Kirkendall effect during interdiffusion. Trends relating the chemical properties of the precursors to the phases of the products have been identified. While some precursors contained phosphorus, there was no significant incorporation of phosphorus in any of the products. An increase of the NP size during sulfidation and selenidation is consistent with ripening. The application of Ni sulfide and selenide NPs as electrocatalysts for the hydrogen evolution reaction is also demonstrated.}, number={4}, journal={CARBON ENERGY}, publisher={Wiley}, author={Lynch, Brian B. and Kelliher, Andrew P. and Anderson, Bryan D. and Japit, Alexander and Spencer, Michael A. and Rizvi, Mehedi H. and Sarac, Mehmet F. and Augustyn, Veronica and Tracy, Joseph B.}, year={2021}, month={Aug}, pages={582–589} } @article{marusak_johnston-peck_wu_anderson_tracy_2017, title={Size and Composition Control of CoNi Nanoparticles and Their Conversion into Phosphides}, volume={29}, ISSN={["1520-5002"]}, url={https://doi.org/10.1021/acs.chemmater.6b04335}, DOI={10.1021/acs.chemmater.6b04335}, abstractNote={The synthesis of binary rather than unary metal nanoparticles (NPs) introduces challenges in controlling the chemistry and opportunities to tune the properties of the products. Ligand-stabilized CoNi NPs were synthesized by heating mixtures of Ni(acac)2 and Co(acac)2 (acac = acetylacetonate), oleylamine, trioctylphosphine, and trioctylphosphine oxide to 240 °C. Varying the amounts of the Co and Ni precursors allows for control over the NP size, giving diameters of 6–18 nm and compositions (XCo) of ≤0.7. The products are enriched with Ni, in comparison with the Co:Ni ratio of the precursors. Co and Ni are both dispersed throughout the NPs, while the shells are enriched with Co. The magnetic properties of CoNi NPs are between those of magnetically soft Ni and magnetically harder Co, with additional effects caused by oxidation under ambient atmosphere, which gives rise to exchange bias. When the reaction mixture for synthesizing CoNi NPs is heated to 300 °C, trioctylphosphine decomposes, and conversion into ...}, number={7}, journal={CHEMISTRY OF MATERIALS}, publisher={American Chemical Society (ACS)}, author={Marusak, Katherine E. and Johnston-Peck, Aaron C. and Wu, Wei-Chen and Anderson, Bryan D. and Tracy, Joseph B.}, year={2017}, month={Apr}, pages={2739–2747} } @article{anderson_wu_tracy_2016, title={Silica Overcoating of CdSe/CdS Core/Shell Quantum Dot Nanorods with Controlled Morphologies}, volume={28}, ISSN={["1520-5002"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000380576700010&KeyUID=WOS:000380576700010}, DOI={10.1021/acs.chemmater.6b01225}, abstractNote={CdSe/CdS core/shell quantum dot nanorods (QDNRs) exhibit anisotropic optical properties. Overcoating QDNRs with silica (SiO2) shells is desirable for protecting the surface of the inorganic core, imparting dispersibility in water, and allowing functionalization with silanes. While several methods have been developed for encapsulating spherical CdSe-based quantum dots in SiO2, extension of these approaches to QDNRs has been limited. Here, we report a reverse microemulsion approach for controlled deposition of SiO2 overcoatings with thicknesses of 2–12 nm onto CdSe/CdS QDNRs with aspect ratios of up to 19. Addition of poly(ethylene glycol) silane during SiO2 deposition terminates the reaction and allows facile control over the shell thickness, especially for thinner shells. By independently controlling the amounts of tetraethyl orthosilicate, ammonium hydroxide (NH4OH), and water, morphological control is achieved, giving uniform SiO2 shells or heterogenenous deposition onto the ends of QDNRs as lobed structures, nanolollipops (single lobe) or nanodumbbells (double lobes). Especially for high-aspect ratio QDNRs, we report breakage of the double-lobed structures. The SiO2 overcoating process causes a reduction in the fluorescence quantum yield of approximately 20%, which we attribute to use of NH4OH as a catalyst in this reaction.}, number={14}, journal={CHEMISTRY OF MATERIALS}, author={Anderson, Bryan D. and Wu, Wei-Chen and Tracy, Joseph B.}, year={2016}, month={Jul}, pages={4945–4952} } @misc{anderson_tracy_2014, title={Nanoparticle conversion chemistry: Kirkendall effect, galvanic exchange, and anion exchange}, volume={6}, ISSN={["2040-3372"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000344997500001&KeyUID=WOS:000344997500001}, DOI={10.1039/c4nr02025a}, abstractNote={Review article discussing recent advances in conversion chemistry of nanoparticles through the Kirkendall effect, galvanic exchange, and anion exchange.}, number={21}, journal={NANOSCALE}, author={Anderson, Bryan D. and Tracy, Joseph B.}, year={2014}, pages={12195–12216} } @article{sarac_anderson_pearce_railsback_oni_white_hensley_lebeau_melechko_tracy_2013, title={Airbrushed Nickel Nanoparticles for Large-Area Growth of Vertically Aligned Carbon Nanofibers on Metal (Al, Cu, Ti) Surfaces}, volume={5}, ISSN={["1944-8244"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000330016500022&KeyUID=WOS:000330016500022}, DOI={10.1021/am401889t}, abstractNote={Vertically aligned carbon nanofibers (VACNFs) were grown by plasma-enhanced chemical vapor deposition (PECVD) using Ni nanoparticle (NP) catalysts that were deposited by airbrushing onto Si, Al, Cu, and Ti substrates. Airbrushing is a simple method for depositing catalyst NPs over large areas that is compatible with roll-to-roll processing. The distribution and morphology of VACNFs are affected by the airbrushing parameters and the composition of the metal foil. Highly concentrated Ni NPs in heptane give more uniform distributions than pentane and hexanes, resulting in more uniform coverage of VACNFs. For VACNF growth on metal foils, Si micropowder was added as a precursor for Si-enriched coatings formed in situ on the VACNFs that impart mechanical rigidity. Interactions between the catalyst NPs and the metal substrates impart control over the VACNF morphology. Growth of carbon nanostructures on Cu is particularly noteworthy because the miscibility of Ni with Cu poses challenges for VACNF growth, and carbon nanostructures anchored to Cu substrates are desired as anode materials for Li-ion batteries and for thermal interface materials.}, number={18}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Sarac, Mehmet F. and Anderson, Bryan D. and Pearce, Ryan C. and Railsback, Justin G. and Oni, Adedapo A. and White, Ryan M. and Hensley, Dale K. and LeBeau, James M. and Melechko, Anatoli V. and Tracy, Joseph B.}, year={2013}, month={Sep}, pages={8955–8960} } @article{pearce_railsback_anderson_sarac_mcknight_tracy_melechko_2013, title={Transfer of Vertically Aligned Carbon Nanofibers to Polydimethylsiloxane (PDMS) While Maintaining their Alignment and Impalefection Functionality}, volume={5}, ISSN={["1944-8252"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000315079700055&KeyUID=WOS:000315079700055}, DOI={10.1021/am302501z}, abstractNote={Vertically aligned carbon nanofibers (VACNFs) are synthesized on Al 3003 alloy substrates by direct current plasma-enhanced chemical vapor deposition. Chemically synthesized Ni nanoparticles were used as the catalyst for growth. The Si-containing coating (SiN(x)) typically created when VACNFs are grown on silicon was produced by adding Si microparticles prior to growth. The fiber arrays were transferred to PDMS by spin coating a layer on the grown substrates, curing the PDMS, and etching away the Al in KOH. The fiber arrays contain many fibers over 15 μm (long enough to protrude from the PDMS film and penetrate cell membranes) and SiN(x) coatings as observed by SEM, EDX, and fluorescence microscopy. The free-standing array in PDMS was loaded with pVENUS-C1 plasmid and human brain microcapillary endothelial (HBMEC) cells and was successfully impalefected.}, number={3}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Pearce, Ryan C. and Railsback, Justin G. and Anderson, Bryan D. and Sarac, Mehmet F. and McKnight, Timothy E. and Tracy, Joseph B. and Melechko, Anatoli V.}, year={2013}, month={Feb}, pages={878–882} }