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The global ammonia yield is critical to the fertilizer industry as the global food demand is highly dependent on it, whereas, NH3 is also a key chemical for pharmaceutical, textile, plastic, explosive, and dye-making industries. At present, the demand for NH3 is fulfilled by the Haber-Bosch method, which consumes 1-3% of global energy and causes 0.5-1% CO2 emission every year. To reduce emissions and improve energy efficiency, the electrochemical nitrogen gas reduction reaction (N2RR) has received much attention and support after the funding announcement by the U.S. Department of Energy. In this work, we have created hollow CuAu nanoboxes with Cu-rich inner walls to improve the NH3 Faradaic efficiency in N2RR. These beveled nanoboxes are produced in different degrees of corner and edge etching, which produces both polyhedral and concave structures. In N2RR, the binary CuAu nanoboxes enhanced NH3 production compared to individual Au and Cu nanocubes. The results of DFT calculations suggest the Cu-rich inner walls in the hollow beveled CuAu nanoboxes play a major role in their performance by reducing the free energy ΔG*NNH for the potential-determining step to form *NNH (* + N2(g) + H+ + e- → *NNH). Meanwhile, the results in 10-cycle and solar-illuminated N2RR indicate the beveled CuAu nanoboxes are not only robust electrocatalysts but show promise in photocatalysis as well.

Modulation of bimetallic nanocatalysts with atomic precision would allow for significant increases in catalyst activity through the optimization of heteroatomic interplay. In practice, this level o...

Copper is an earth-abundant element that can be used to reduce the high cost and unsatisfactory durability of pure Pt catalysts by the formation of bimetallic Pt–M nanocrystals. Among CuPt nanostru...

The global ammonia yield is critical to the fertilizer industry as the global food demand is highly dependent on it, whereas, NH

The combined functionality of components in organic–inorganic hybrid nanomaterials render them efficient nanoreactors. However, the development in this field is limited due to a lack of synthetic avenues and systematic control of the growth kinetics of hybrid structures. In this work, we take advantage of an ionic switch for regio-control of Au-BINOL(1,1′-Bi-2-naphthol) hybrid nanostructures. Aromatic BINOL molecules assemble into nanospheres, concomitant with the growth of the Au nanocrystals. The morphological evolution of Au nanocrystals is solely controlled by the presence of halides in the synthetic system. Here we show that quaternary ammonium surfactants (CTAB or CTAC), not only bridging Au and BINOL, but also contributing to the formation of concentric or eccentric structures when their concentrations are tuned to the range of 10–5 to 10–3 M. This facile strategy offers the potential advantage of scalable production, with diverse functional organic–inorganic hybrid nanocomposites being produced ba...

The deformation and stacking of graphene significantly affect the overall electronic and mechanical properties. The graphene sheets are easily stacked each other due to van der Waals attraction. The folded characteristic may prevent graphene stacking and increase the d-spacing between graphenes. It can easily form dense graphene structures with high surface area and be applied on electrode materials of battery, nano-composites and so on. The traditional topographic mapping of atomic force microscope (AFM) is hard to measure the characters of surface deformation and distinguish the folding and stacking. In this study, we apply a novel quantitative nano-mechanical AFM to analyze the reduced-graphene oxide (r-GO). The results indicate that the novel AFM system could recognize the difference between folding and stacking of r-GO effectively. Nevertheless, the images including topography, deformation, adhesion, and elastic modulus show the different phenomena between measuring region, which appears that status on measuring region are folding and stacking, respectively.

A convenient thermal CVD route to core−shell GaP@GaN and GaN@GaP nanowires is developed. The structural analyses indicate that the nanowires exhibit a two-layer and wirelike structure. High-resolution transmission electron microscopy (HRTEM) images reveal misfit dislocation loops at the interface of the nanowires. Unusual temperature dependences of the photoluminescence (PL) intensity of GaP@GaN nanowires are observed, and they are interpreted by the piezoelectric effect induced from lattice mismatch between two semiconductor layers. In the Raman spectra of GaN@GaP nanowires, an unexpected peak at 386 cm-1 is found and assigned to a surface phonon mode.

Deformation induced by contact force from the tip is the major measurement uncertainty using atomic force microscope (AFM) for the apex height of nanoparticles. Additionally, the contact force by the AFM tip is difficult and not reliable in traditional tapping and contact modes. In this work, the contact forces applied by the AFM were varied using a peak-force tapping method, which is unique technique to perform force-controlled scanning, to characterize the deformation of nanoparticles. The obtained measurement results were compared with a theoretical model developed for predicting the deformation between PS nanoparticles and tip/substrate. It was found that the deformation occurred at low force as 0.5 nN for polystyrene nanoparticles on mica substrate. The deformation was fully plastic. In addition, the deformation has a linear relationship with contact force, which is consistent with contact mechanics model.

Although vocational education in Taiwan began more than 150 years ago, no solid foundation has been established to ensure its further development. It is because it was simply designed to fulfill the need for production human resources (HR) of businesses in the absence of a curriculum. Also, despite a set of regulations announced in 1902 (the 28th year of Emperor Guangsui’s Regime, Qing Dynast), they were simple rules without specifying the contents of any curriculum.

High-quality GaP, GaP@GaN and GaN@GaP nanowires were grown by a convenient vapor deposition technique. The wire-like and two-layers structures of GaP@GaN and GaN@GaP core-shell nanowires were clearly resolved using X-ray powder diffraction and high-resolution transmission electron microscopy (HRTEM) and their growth directions were identified. Photoluminescence intensity of GaP@GaN nanowires increased as temperature increased. The result was interpreted by the piezoelectric effect induced from lattice mismatch between two semiconductor layers. An unexpected peak at 386 cm-1 was found in the Raman spectra of GaN@GaP and assigned to a surface phonon mode due to the interface. Detailed synthetic conditions and possible growth mechanisms of those nanowires were proposed.