Au@Cu2- x S core-shell nanocrystals (NCs) have been synthesized under large lattice mismatch with high crystallinity, controllable shape, and nonstoichiometric composition. Both experimental observations and simulations are used to verify the flexible dual-mode plasmon coupling. The enhanced photothermal effect is harnessed for diverse HeLa cancer cell ablation applications in the NIR-I window (750-900 nm) and the NIR-II window (1000-1400 nm).
in such areas. [2] The ideal efficiency of solar energy conversion of plasmonic metalbased hybrid catalysts comes from anisotropic crystallization, heterointerface. [3] Besides the morphology of plasmonic metal nanocrystals (NCs), the solar energy conversion efficiency of plasmonic metalsemiconductor NCs should be sensitive to the manner of coupling between metal NCs and the semiconductor. [4] Therefore, it is highly desirable to explore a versatile strategy to synthesize accurately controlled anisotropic configuration, monocrystalline shell, and intended site-selective heterocontact between plasmonic metal and semiconductor.The absorbance range is an essential factor on the efficiency of light harvesting and photoelectric catalysis. So far, most of the applications based on plasmonic metal hybrid NCs are limited in specific spectral range, because most of plasmonic metal nanostructures only have plasmon resonances in the visible regions. [5] Au nanorods (NRs), [6] because of its intriguing longitudinal surface plasmon resonance (LSPR), can be excited by incident light polarized along the axial direction. Therefore, it can be synthetically tailored across a broad spectral range and In this communication, light harvesting and photoelectrochemical (PEC) hydrogen generation beyond the visible region are realized by an anisotropic plasmonic metal/semiconductor hybrid photocatalyst with precise control of their topology and heterointerface. Controlling the intended configuration of the photocatalytic semiconductor to anisotropic Au nanorods' plasmonic hot spots, through a water phase cation exchange strategy, the site-selective overgrowth of a CdSe shell evolving from a core/shell to a nanodumbbell is realized successfully. Using this strategy, tip-preferred efficient photoinduced electron/hole separation and plasmon enhancement can be realized. Thus, the PEC hydrogen generation activity of the Au/CdSe nanodumbbell is 45.29 µmol cm −2 h −1 (nearly 4 times than the core/shell structure) beyond vis (λ > 700 nm) illumination and exhibits a high faradic efficiency of 96% and excellent stability with a constant photocurrent for 5 days. Using surface photovoltage microscopy, it is further demonstrated that the efficient plasmonic hot charge spatial separation, which hot electrons can inject into CdSe semiconductors, leads to excellent performance in the Au/CdSe nanodumbbell.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/aenm.201803889.Including the visible light (400-700 nm), the light harvest beyond visible (λ > 700 nm with ≈43% ratio of solar energy) to contribute effective photocatalysis is important but rarely studied. [1] Plasmonic metal based anisotropic metal-semiconductor hybrid nanostructures emerge to be potential materials for applications
The last 5 years have witnessed rapid progress in the field of hybrid nanostructures toward enhanced optical and electronic properties. On this topic, we focus on the relevant progress that has been achieved on the basis of cation/anion exchange reactions (CERs/AERs). Different from those direct synthesis strategies, CERs/AERs can offer more freedom in tuning the chemical composition, crystal phases, doping, interfaces, and morphologies, which are key parameters to determine the optical and electronic properties of the target products. We present several examples, e.g., doped quantum dots (QDs), engineered core-shell QDs, metal-semiconductor hybrid nanostructures, hollow structures, and inorganic perovskite nanocrystals. These upgraded structures afforded by CERs/ AERs generally exhibit improved properties, such as increased quantum yields, prolonged lifetimes, and well-engineered band gaps for charge transportation and recombination, thus providing more opportunities for further advanced applications.
Achieving ordered arrays of nanoparticles (NPs) with controlled packing symmetry and interparticle spacing is of great importance to design complex metamaterials. Herein, we report softness-and size-dependent self-assembly behavior of polystyrene-grafted Au NPs (Au@PS NPs). We varied the core size of Au NPs from 1.9 to 9.6 nm and the number-average molecular weight (M n ) of thiol-terminated polystyrene from 1.8 to 7.9 kg mol −1 . The optimal packing model based on an "effective softness" parameter λ eff that accounts for close-packed and semidilute brush regimes could predict the effective radius of Au@PS NPs (within ±9%) for a wide range of PS M n , grafting density, and Au core size. With increasing λ eff , the self-assembled Au@PS NP superlattices undergo a symmetry transition from hexagonal close packed (hcp) to body-centered tetragonal (bct) to body-centered cubic (bcc). This work demonstrates the effective softness model as a simple but robust tool for the design of NP superlattices with precisely controlled interparticle distance and packing symmetry, both of which are critical for the development of sophisticated materials through control of nanoscale structure.
Phosphine-initiated cation exchange is a well-known inorganic chemistry reaction. In this work, different phosphines have been used to modulate the thermodynamic and kinetic parameters of the cation exchange reaction to synthesize complex semiconductor nanostructures. Besides preserving the original shape and size, phosphine-initiated cation exchange reactions show potential to precisely tune the crystallinity and composition of metal/semiconductor core-shell and doped nanocrystals. Furthermore, systematic studies on different phosphines and on the elementary reaction mechanisms have been performed.
Summary• AtDjB1 belongs to the J-protein family in Arabidopsis thaliana. Its biological functions in plants are largely unknown.• In this study, we examined the roles of AtDjB1 in resisting heat and oxidative stresses in A. thaliana using reverse genetic analysis.• AtDjB1 knockout plants (atj1-1) were more sensitive to heat stress than wildtype plants, and displayed decreased concentrations of ascorbate (ASC), and increased concentrations of hydrogen peroxide (H 2 O 2 ) and oxidative products after heat shock. Application of H 2 O 2 accelerated cell death and decreased seedling viability in atj1-1. Exogenous ASC conferred much greater thermotolerance in atj1-1 than in wildtype plants, suggesting that a lower concentration of ASC in atj1-1 could be responsible for the increased concentration of H 2 O 2 and decreased thermotolerance. Furthermore, AtDjB1 was found to localize to mitochondria, directly interact with a mitochondrial heat-shock protein 70 (mtHSC70-1), and stimulate ATPase activity of mtHSC70-1. AtDjB1 knockout led to the accumulation of cellular ATP and decreased seedling respiration, indicating that AtDjB1 modulated the ASC concentration probably through affecting the function of mitochondria.• Taken together, these results suggest that AtDjB1 plays a crucial role in maintaining redox homeostasis, and facilitates thermotolerance by protecting cells against heat-induced oxidative damage.
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