The next generation of high-performance batteries should include alternative chemistries that are inherently safer to operate than nonaqueous lithium-based batteries. Aqueous zinc-based can answer challenge because monolithic zinc sponge anodes be cycled in nickel-zinc alkaline cells hundreds thousands times without undergoing passivation or macroscale dendrite formation. We demonstrate the three-dimensional (3D) form-factor elevates performance three fields use: (i) >90% theoretical depth...

Au nanoparticles (NPs) with protecting organothiolate ligands and core diameters smaller than 2 nm are interesting materials because their size-dependent properties range from metal-like to molecule-like. This Account focuses on the most thoroughly investigated of these NPs, Au(25)L(18). Future advances in nanocluster catalysis electronic miniaturization biological applications such as drug delivery will depend a thorough understanding nanoscale which molecule-like characteristics appear....

Zinc-based replacements for Li-ion batteries are now feasible by using 3D-interconnected Zn sponges that suppress dendrite formation when cycled.

New approaches to electrospray ionization mass spectrometry (ESI-MS)with exact compositional assignmentsof small (Au25) nanoparticles with uniform and mixed protecting organothiolate monolayers are described. The results expand the scope of analysis reveal a rich chemistry behavior. ESI-MS solutions phenylethanethiolate monolayer-protected gold clusters (MPCs), Au25(SC2Ph)18, containing alkali metal acetate salts (MOAc) produce spectra in which, for Na+, K+, Rb+, Cs+ acetates, dominant...

Excited-state relaxation dynamics of a gold cluster, the anion Au25(SCH2CH2Ph)18−, with known crystal structure are measured femtosecond laser spectroscopies. The cluster consists an icosahedral Au13 core bonded to six Au2(SCH2CH2Ph)3 semirings. Pump−probe experiments excite electronic transitions and then monitor system as it reaches quasi-equilibrium in lower-energy fluorescing state(s) localized on semiring moieties. measurements show that extremely rapid (<200 fs) internal conversion...

Nanoscale MnO<italic>x</italic> expressed in 3D carbon nanofoam electrodes exhibits both pseudocapacitive and battery-like charge-storage using a mixed Na⁺ : Zn²⁺ aqueous electrolyte.

The extended interface between Cu nanoparticles and TiO₂ aerogel supports stabilizes against oxidation enough to preserve its plasmonic behavior, even after exposure air.

A single phase (THF) synthesis of monodisperse [Oct(4)N(+)][Au(25)(SR)(18)(-)] nanoparticles is described that yields insights into pathways by which it formed from initially produced larger nanoparticles. Including the Oct(4)N(+)Br(-) salt in a reported synthetic procedure enables production reduced having fully occupied HOMO molecular energy level (Au(25)(SR)(18)(-), as opposed to partially oxidized state, Au(25)(SR)(18)(0)). The revised accommodates several (but not all) different...

The historically poor electrochemical rechargeability of Zn in alkaline electrolyte has hindered the commercial viability Ni–Zn batteries, a system otherwise interest because high specific energy (up to 140 Wh kg–1). We have redesigned anode as three-dimensional (3D), monolithic porous architecture ("sponge") that exhibits unprecedented capacity and dendrite-free cycling. Maintaining integrity 3D sponge throughout charge–discharge is required ultimately achieve technologically relevant...

We previously demonstrated that a redesign of the form factor for zinc (Zn) anodes to monolithic, porous 3D-wired sponge sets new benchmark rechargeable alkaline Zn batteries. By engineering solid volume fraction from benchmarked 20% (Zn20) 30% (Zn30), we increase degree metallic connectivity, boost mechanical integrity, and out-power first-generation counterpart. Visualizing internal structure using X-ray computed microtomography (XCMT) confirms increased interconnectivity within denser...

Proton nuclear magnetic resonance (NMR) was used to measure the rate constant and activation energy barrier for electron self-exchanges of phenylethanethiolate-protected nanoparticle couple [Au25(SC2Ph)18]0/1−. The thiolate ligand α-methylene proton resonances electrolytically prepared CD2Cl2 solutions oxidized (Au250) reduced (Au251−) nanoparticles exhibit characteristic chemical shifts line-shapes. That α-CH2 protons in Au250 is shifted ∼2 ppm downfield from Au251− has an increased...

Ligand exchange reactions of Au25(SCH2CH2Ph)18 with hexanethiol (HSC6) and thiophenol (HSPh) as incoming ligands, Brust reaction nanoparticle syntheses using mixtures thiols (HSCH2CH2Ph HSC6), produce nanoparticles having different, ideally statistically determined, relative populations the two thiolate ligands (X Y), i.e., Au25(X)m(Y)m′, where m m′ vary but always sum to 18. By choice reactant concentrations, can reach an equilibrium state or a near-complete be at kinetically determined...

We report the first collision-induced dissociation tandem mass spectrometry (CID MS/MS) of a thiolate-protected Au nanoparticle that has crystallographically determined structure. CID spectra assert pathways for mixed monolayer Na(x)Au(25)(SC(2)H(4)Ph)(18-y)(S(C(2)H(4)O)(5)CH(3))(y) centrally involve semi-ring Au(2)L(3) coordination (L = some combination two thiolate ligands) constitutes nanoparticle's protecting The data additionally confirm charge state assignments in spectra. Prominent...

Commercial primary zinc–air batteries provide 450 Wh kgcell–1 (at the cell level), but practical specific energy of secondary remains unclear. Using a specific-energy model and data from reported cells, we show that some rechargeable electrode materials may already be capable enabling system-level energies between 200 kgsys–1. These values rival best-case projections for battery packs using lithium–sulfur, lithium metal paired with layered oxides, or open lithium–air. By performing...

The progress of ligand exchange reactions between the ligands Au25(SR)18− nanoparticles (SR = S(CH2)2Ph) and thiols with electron-withdrawing substituents (HSPh-p-X; X Br, NO2) was monitored using 1H nuclear magnetic resonance. As proceed, introduction electron withdrawing −SPhX into nanoparticle shell causes a shift redox waves (Au251+/0 Au250/1−) to more positive potentials. Combining NMR electrochemical results reveals nearly linear formal potentials as function average number exchanged...

Abstract Rechargeable zinc–air batteries may become safe, sustainable, low‐cost, and energy‐dense alternatives to Li‐ion for many applications, but problems associated with today's air‐breathing electrodes limit performance. To overcome this challenge, researchers have investigated hundreds of electrode variations over the last decade. Unfortunately, efficacy these remains ambiguous due nonstandardized cycling protocols that map areal‐energy values spanning five orders magnitude. compete...

We show that zinc (Zn) batteries are the lowest cost and most energy dense of rechargeable rely on abundant, low-risk elements. advance Zn with a green synthesis lowers boosts performance electrodes.

Incorporating Al³⁺ within α-Ni(OH)₂ nanosheets provides higher capacity in Ni–Zn cells with phase stability upon cycling compared to the other tested divalent substituents and unsubstituted α-Ni(OH)₂.

Mass spectrally detected products of ligand exchange reactions the nanoparticle [Au25(SC2H4C6H5)18](1-), (abbrev. Au25(SC2Ph)18), where dithiol is toluene-3,4-dithiol, CH3C6H3(SH)2, include nanoparticles containing both doubly (bidentate, or chelating) and singly bonded dithiol. The bidentate binding displaces two original -SC2Ph ligands, one ligand, while maintaining, for mass species, occupancy 18 ligation sites. Extended reaction times result in an apparent maximum six chelated...

Abstract Background: Classifying breast cancer into molecular subtypes (Luminal A/B, Her2-enriched, and Basal-like) has proven to be biologically clinically informative. Recently, we developed a gene expression based protocol (PAM50) that provides reliable subtype classification as well independent prognostic utility (Parker et al, J Clin Oncol 2009). In this study, evaluated the ability of PAM50 predict pathological complete response (pCR) anthracycline/taxane-based chemotherapy in...