Glucose electrolysis offers a prospect of value-added glucaric acid synthesis and energysaving hydrogen production from the biomass-based platform molecules. Here we report that nanostructured NiFe oxide (NiFeO x ) and nitride (NiFeN x ) catalysts, synthesized from NiFe layered double hydroxide nanosheet arrays on three-dimensional Ni foams, demonstrate a high activity and selectivity towards anodic glucose oxidation. The electrolytic cell assembled with these two catalysts can deliver 100 mA cm −2 at 1.39 V. A faradaic efficiency of 87% and glucaric acid yield of 83% are obtained from the glucose electrolysis, which takes place via a guluronic acid pathway evidenced by in-situ infrared spectroscopy. A rigorous process model combined with a techno-economic analysis shows that the electrochemical reduction of glucose produces glucaric acid at a 54% lower cost than the current chemical approach. This work suggests that glucose electrolysis is an energy-saving and cost-effective approach for H 2 production and biomass valorization.

In this study, the suspension of MoO3 nanobelts was first prepared in a hydrothermal way from Mo powders and H2O2 solution, which could be transformed into the suspension of H x MoO3 nanobelts under an acidic condition using N2H4·H2O as the reducing agent. Three paper-form samples made from MoO3 and H x MoO3 nanobelts (low or high hydrogen content) were then fabricated via a vacuum filtration method, followed by their structural comparative analysis such as FESEM, XRD, Raman spectra, and XPS, etc. The measurement of electric resistances at room temperature shows that the conductance of H x MoO3 nanobelts is greatly improved because of hydrogen doping. The temperature-dependent resistances of H x MoO3 nanobelts agree with the exponential correlation, supporting that the conducting carriers are the quasi-free electrons released from Mo5+. In addition, the formation process of H x MoO3 nanobelts from MoO3 nanobelts is also discussed.

The elasticity and piezoelectricity of zinc oxide (ZnO) crystals and single layers are investigated from the first-principles calculations. It is found that a ZnO thin film less than three Zn-O layers prefers a planar graphite-like structure to the wurtzite structure. ZnO single layers are much more flexible than graphite single layers in the elasticity and stronger than boron nitride single layers in the piezoelectricity. Single-walled ZnO nanotubes (SWZONTs) can exist in principle because of their negative binding energy. The piezoelectricity of SWZONTs depends on their chirality.For most ZnO nanotubes except the zigzag type, twists around the tube axis will induce axial polarizations. A possible scheme is proposed to achieve the SWZONTs from the solid-vapor phase process with carbon nanotubes as templates. PACS numbers: 62.25.+g, 62.20.Dc, 77.65.-j 1 I. INTRODUCTION Zinc oxide (ZnO) materials have attracted extensive attention for half a century because of their excellent performance in optics, electronics and photoelectronics. 1 They are important for low cost productions of green, blue-ultraviolet, and white light-emitting devices due to their wide band gap (∼3.37 eV) and large exciton binding energy (∼60 meV). They can also be used as sensors and transducers owing to their strong piezoelectricity. Recently, many ZnO nanostructures have been synthesized in experiments. 2 Among them, the quasi-one-dimensional structures have become the leading research objects because of their novel chemical, electrical, mechanical and optical properties. 3 The ultraviolet lasing in ZnO nanowires 4,5 and strong photoluminescence in ZnO nanorods 6 have been demonstrated.Nanobelts, nanorings and nanohelixes are also synthesized, 7,8,9,10 which may be useful for field-effect transistors. 11Since the discovery of carbon nanotubes in 1991, 12 the synthesis of tubular nanostructures has raised worldwide interest. A lot of inorganic nanotubes, such as ZrS 2 , NbSe 2 , SiO 2 , TiO 2 , BN nanotubes, etc. are achieved by several groups. 13 Researchers have also tried to fabricate ZnO nanotubes through various methods including thermal reduction, 14 vapor phase growth, 15,16,17 hydrothermal growth, 18 vapor-solid process, 19 sol-gel template process, 20 plasma-assisted molecular beam epitaxy, 21,22 pyrolysis of zinc acetylacetonate, 23 and Zn(NH 3 ) 2+ 4 precursor thermal decomposition. 24 All ZnO nanotubes thus obtained have the wurtzite structure with diameter of 30-450 nm and thickness of 4-100 nm. Much effort has been made to realize much thinner and smaller ZnO nanotubes. A natural question is: Can we manufacture single-walled ZnO nanotubes (SWZONTs)? In this paper, We will answer this question based on the first-principles calculations (the ABINIT package 25 ) and the experimental methods 15,16,17,19 for synthesizing ZnO nanobelts and nanotubes with the wurtzite structure. Additionally, we will investigate the elasticity and piezoelectricity of ZnO crystals and single layers within the framework of density-functional theory (DFT) ...

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A new molecular motor is conceptually constructed from a double-walled carbon nanotube (DWNT) consisting of a long inner single-walled carbon nanotube (SWNT) and a short outer SWNT with different chirality. The interaction between inner and outer tubes is the sum of the Lennard-Jones potentials between carbon atoms in inner tube and those in outer one. Within the framework of Smoluchowski-Feynman ratchet, it is theoretically shown that this system in an isothermal bath will exhibit a unidirectional rotation in the presence of a varying axial electrical voltage. Moreover, the possibility to manufacture this electrical motor from DWNT is discussed under the current conditions of experimental technique.

Design and engineering of bifunctional catalysts are critical in the development of electrochemical full water splitting. In this study, 4-ethylphenylacetylene-functionalized iridium (Ir− C, 1.7 ± 0.3 nm in diameter) nanoparticles are found to exhibit markedly enhanced electrocatalytic activity toward both hydrogen and oxygen evolution reactions (HER and OER) in acidic and alkaline media, in comparison to the nanoparticles capped with mercapto and nitrene derivatives. Remarkably, the HER and OER performances in alkaline media are even better than those of commercial Ir/C and Pt/C benchmarks. This is accounted for by the formation of Ir−CC− conjugated interfacial linkage that leads to significant intraparticle charge delocalization and hence manipulation of the electron density of the Ir nanoparticles and interactions with key reaction intermediates. This is indeed confirmed by results from both spectroscopic measurements and density functional theory calculations. With Ir−C nanoparticles as both the cathode and anode catalysts for electrochemical water splitting, a low cell voltage of 1.495 and 1.473 V is needed to reach the current density of 10 mA cm −2 in alkaline and acidic media, respectively. Such a performance is markedly better than that of commercial Ir/C (1.548 and 1.561 V) and relevant catalysts reported in recent literature, highlighting the significance of interfacial engineering in the development of high-performance bifunctional electrocatalysts.

Electroreduction of carbon dioxide (CO2RR) into fuels and chemicals is an appealing approach to tackle CO2 emission challenges.

The development of high‐efficiency bifunctional electrocatalyst for oxygen reduction and evolution reactions (ORR/OER) is critical for rechargeable metal–air batteries, a typical electrochemical energy storage and conversion technology. This work reports a general approach for the synthesis of Pd@PdO–Co3O4 nanocubes using the zeolite‐type metal–organic framework (MOF) as a template. The as‐synthesized materials exhibit a high electrocatalytic activity toward OER and ORR, which is comparable to those of commercial RuO2 and Pt/C electrocatalysts, while its cycle performance and stability are much higher than those of commercial RuO2 and Pt/C electrocatalysts. Various physicochemical characterizations and density functional theory calculations indicate that the favorable electrochemical performance of the Pd@PdO–Co3O4 nanocubes is mainly attributed to the synergistic effect between PdO and the robust hollow structure composed of interconnected crystalline Co3O4 nanocubes. This work establishes an efficient approach for the controlled design and synthesis of MOF‐templated hybrid nanomaterials, and provides a great potential for developing high‐performance electrocatalysts in energy storage and conversion.