@article{park_liu_gardner_johnson_keeler_ortiz_rabah_ford_2020, title={Biohybrid nanofibers containing manganese oxide-forming fungi for heavy metal removal from water}, volume={15}, ISSN={["1558-9250"]}, DOI={10.1177/1558925019898954}, abstractNote={ Manganese-oxidizing fungi support bioremediation through the conversion of manganese ions into manganese oxide deposits that in turn adsorb manganese and other heavy metal ions from the environment. Manganese-oxidizing fungi were immobilized onto nanofiber surfaces to assist remediation of heavy metal–contaminated water. Two fungal isolates, Coniothyrium sp. and Coprinellus sp., from a Superfund site (Lot 86, Farm Unit #1) water treatment system were incubated in the presence of nanofibers. Fungal hyphae had strong association with nanofiber surfaces. Upon fungal attachment to manganese chloride–seeded nanofibers, Coniothyrium sp. catalyzed the conformal deposition of manganese oxide along hyphae and nanofibers, but Coprinellus sp. catalyzed manganese oxide only along its hyphae. Fungi–nanofiber hybrids removed various heavy metals from the water. Heavy metal ions were adsorbed into manganese oxide crystalline structure, possibly by ion exchange with manganese within the manganese oxide. Hybrid materials of fungal hyphae and manganese oxides confined to nanofiber-adsorbed heavy metal ions from water. }, journal={JOURNAL OF ENGINEERED FIBERS AND FABRICS}, author={Park, Yaewon and Liu, Shuang and Gardner, Terrence and Johnson, Drake and Keeler, Aaron and Ortiz, Nathalia and Rabah, Ghada and Ford, Ericka}, year={2020}, month={Jan} }
 @article{ortiz_zoellner_kumar_janelli_tang_maggard_wang_2018, title={Composite Ferroelectric and Plasmonic Particles for Hot Charge Separation and Photocatalytic Hydrogen Gas Production}, volume={1}, ISSN={["2574-0962"]}, DOI={10.1021/acsaem.8b00772}, abstractNote={Plasmonic nanoparticles are excellent light absorbers for harvesting solar energy, resulting in hot electrons that can be utilized in photocatalytic hydrogen production. However, the hot electrons generated in a localized surface plasmon resonance process have a very short lifetime and are challenging to use efficiently. Herein, using near IR light irradiation, we show that by combining gold nanorods (AuNRs) with ferroelectric PbTiO3 particles that possess a large remanent electric dipole moment, hot charges generated on plasmonic particles can be injected into ferroelectric materials and drive the photocatalysis reaction. Compared to metallic Pt-end-capped AuNRs, the efficiency of using hot electrons for photocatalytic reactions is enhanced for the composite catalyst, which improves the light-to-chemical energy conversion efficiencies by about 1 order of magnitude for the same amount of plasmonic particles being used.}, number={9}, journal={ACS APPLIED ENERGY MATERIALS}, author={Ortiz, Nathalia and Zoellner, Brandon and Kumar, Vineet and Janelli, Tara and Tang, Shuli and Maggard, Paul A. and Wang, Gufeng}, year={2018}, month={Sep}, pages={4606–4616} }
 @article{ortiz_hong_fonseca_liu_wang_2017, title={Anisotropic Overgrowth of Palladium on Gold Nanorods in the Presence of Salicylic Acid Family Additives}, volume={121}, ISSN={["1932-7447"]}, DOI={10.1021/acs.jpcc.6b12024}, abstractNote={We explored the use of salicylic acid (SA) and its derivatives 5-formylsalicylic acid (FSA) and 5-sulfosalicylic acid (SSA) as organic additives to cetyltrimethylammonium bromide (CTAB) in synthesizing gold nanorods (AuNRs) followed by palladium (Pd) capping at the ends of AuNRs. In the AuNR synthesis step, SA family additives in the presence of low concentration of CTAB (50 mM) serve as both the prereducing agent and the cofactor in nanorod growth. At an optimum additive/CTAB ratio (0.1–0.2), AuNRs grow to the longest length. At low additive concentrations, the gold seeds do not grow. At high concentrations, the longitudinal growth of AuNRs is disrupted because the excessive additive disturbs the ligand structure, leading to more isotropic growth. In the Pd overgrowth step, Pd starts to grow from both ends for AuNRs synthesized at optimum additive/CTAB ratios. Feeding more Pd grows the particles into a core–shell structure, possibly because there lacks a tight ligand layer on Pd that favors the longitudi...}, number={3}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Ortiz, Nathalia and Hong, Soung Joung and Fonseca, Francini and Liu, Yang and Wang, Gufeng}, year={2017}, month={Jan}, pages={1876–1883} }
 @article{ortiz_zoellner_hong_jo_wang_liu_maggard_wang_2017, title={Harnessing Hot Electrons from Near IR Light for Hydrogen Production Using Pt-End-Capped-AuNRs}, volume={9}, ISSN={["1944-8244"]}, DOI={10.1021/acsami.7b05064}, abstractNote={Gold nanorods show great potential in harvesting natural sunlight and generating hot charge carriers that can be employed to produce electrical or chemical energies. We show that photochemical reduction of Pt(IV) to Pt metal mainly takes place at the ends of gold nanorods (AuNRs), suggesting photon-induced hot electrons are localized in a time-averaged manner at AuNR ends. To use these hot electrons efficiently, a novel synthetic method to selectively overgrow Pt at the ends of AuNRs has been developed. These Pt-end-capped AuNRs show relatively high activity for the production of hydrogen gas using artificial white light, natural sunlight, and more importantly, near IR light at 976 nm. Tuning of the surface plasmon resonance (SPR) wavelength of AuNRs changes the hydrogen gas production rate, indicating that SPR is involved in hot electron generation and photoreduction of hydrogen ions. This study shows that gold nanorods are excellent for converting low-energy photons into high-energy hot electrons, which can be used to drive chemical reactions at their surfaces.}, number={31}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Ortiz, Nathalia and Zoellner, Brandon and Hong, Soung Joung and Jo, Yue and Wang, Tao and Liu, Yang and Maggard, Paul A. and Wang, Gufeng}, year={2017}, month={Aug}, pages={25962–25969} }
 @article{zhao_zhong_wei_ortiz_chen_wang_2016, title={Microscopic Movement of Slow-Diffusing Nanoparticles in Cylindrical Nanopores Studied with Three-Dimensional Tracking}, volume={88}, ISSN={["1520-6882"]}, DOI={10.1021/acs.analchem.5b04944}, abstractNote={To study slow mass transport in confined environments, we developed a three-dimensional (3D) single-particle localization technique to track their microscopic movements in cylindrical nanopores. Under two model conditions, particles are retained much longer inside the pores: (1) increased solvent viscosity, which slows down the particle throughout the whole pore, and (2) increased pore wall affinity, which slows down the particle only at the wall. In viscous solvents, the particle steps decrease proportionally to the increment of the viscosity, leading to macroscopically slow diffusion. As a contrast, the particles in sticky pores are microscopically active by showing limited reduction of step sizes. A restricted diffusion mode, possibly caused by the heterogeneous environment in sticky pores, is the main reason for macroscopically slow diffusion. This study shows that it is possible to differentiate slow diffusion in confined environments caused by different mechanisms.}, number={10}, journal={ANALYTICAL CHEMISTRY}, author={Zhao, Luyang and Zhong, Yaning and Wei, Yanli and Ortiz, Nathalia and Chen, Fang and Wang, Gufeng}, year={2016}, month={May}, pages={5122–5130} }