A facile and effective solvothermal method was developed to tailor the morphology and size of Pt nanocrystals by tuning the concentration of 1-octylamine (OAm). Three shaped Pt nanocrystals (NCs), 0D ...sphere & icosahedra, 2D plate and 3D multipods, were synthesized sequentially with increasing the OAm concentration from 5% to 100% in the solvent mixture OAm and N, N-dimethylformamide (DMF). These Pt NCs exhibited high catalytic performance toward the reduction of p-nitrophenol. The strategy presented in this work open a new avenue for easily developing high dimensional Pt nanocrystals, especially for rare 2D plate.
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•High dimensional Pt nanocrystals were synthesized via a simple solvothermal method.•The shape of Pt NCs was tuned by controlling the 1-octylamine concentration.•2D Pt hexagonal platelet was easily prepared.•3D Pt multipod showed the best catalytic hydrogenation performance.
This paper focuses on the development of a novel climbing robot that is designed for autonomous maintenance of vertical gardens in urban environments. The robot, designed with a unique five-legged ...structure, is equipped with a range of electrical and mechanical components, enabling it to autonomously navigate and maintain a specially designed vertical garden wall facilitating interactive maintenance and growth monitoring. The motion planning and control of the robot were developed to ensure precise and adaptive movement across the vertical garden wall. Advanced algorithms were employed to manage the complex dynamics of the robot’s movements, optimizing its efficiency and effectiveness in navigating and maintaining the garden structure. The operation of the robot in maintaining the vertical garden was evaluated during a two-week trial where the robot successfully performed nearly 8000 leg movements, with only 0.6% requiring human intervention. This demonstrates a high level of autonomy and reliability. This study concludes that the pentapod robot demonstrates significant potential for automating the maintenance of vertical gardens, offering a promising tool for enhancing urban green spaces.
The alloyed multipod-branched Cd
x
Zn
1−
x
S (0
<
x
<
1) NCs have been prepared through a simple solvothermal approach using one solvent ethanolamine without any capping ligands.
The solvent ...ethanolamine with the assistance of cationic doping has been applied to synthesize alloyed multipod-branched Cd
x
Zn
1−
x
S (0
<
x
<
1) nanocrystals through a simple solvothermal route. During the growth of the alloyed multipod-branched nanocrystals, for one thing, the cationic doping enlarges the energy difference between wurtzite and zinc-blende phases; for another thing, the –OH groups of ethanolamine favor the thorough alloying effects and the formation of the zinc-blende-structured seeds, while the –NH
2 groups facilitate the subsequent preferential growth of the wurtzite-phased arms. The composition
x of the alloyed multipod-branched Cd
x
Zn
1−
x
S nanocrystals can be facilely tuned by Cd/Zn initial molar ratios. Furthermore, the absorption edges (corresponding to optical band gaps
E
g
) and the near-band-edge emission peaks are varied with the doping Cd
2+ content
x. It is reasonable for us to believe that ethanolamine can also be employed to fabricate other alloyed multipod-branched nanocrystals such as CdS
x
Se
1−
x
, CdSe
x
Te
1−
x
and CdS
x
Te
1−
x
.
Inorganic hybrid materials with anisotropic noble-metal nanoparticle cores and cagelike transition-metal chalcogenide shells are promising candidates for a wide variety of applications. Herein, we ...report an effective fabrication method for gold multipod nanoparticle (GMN) core–cobalt sulfide shell (GMN@Co x S y ) nanostructures. The unique cagelike morphology is successfully acquired within nanohybrids (GMN@Co x S y nanocages). The cobalt-based metal–organic frameworks can act as versatile sacrificial templates to the desired hybrid nanomaterials through solution-based etching approaches without any undesirable reshaping of GMNs, which are embedded within. Examination of the electrocatalytic oxygen evolution reaction (OER) of the prepared nanohybrids reveals that a type of GMN@Co x S y nanohybrid shows a substantially lower overpotential (η) value (345 mV) compared with those of GMNs (617 mV) and Co x S y nanomaterials (418 mV) at a current density of 10 mA cm–2. The enhanced OER performance is mainly attributed to the highly effective core–shell interfaces stemming from the unique multibranch topologies of the GMN cores as well as the optimized cobalt sulfide shells of the nanohybrids.
A fast and environment-friendly microwave-heating route to synthesize multipod, flower-like and shuttle-like ZnO nano-/microstructures in room-temperature ionic liquids has been reported. The ...products were characterized by X-ray diffraction (XRD), scanning electron microcopy (SEM) and transmission electron microscopy (TEM). These ZnO frameworks are composed of needle-like, cone-like and shuttle-like rods growing homocentrically, respectively.
The Fukushima Daiichi nuclear accident showed that severe events are real-not virtual-threats. In both pressurized water reactor and boiling water reactor nuclear plants, the containment is the last ...resort against radiation leakage, with the integrity of containment being directly linked to nuclear safety. To maintain the containment below Factored Load Category for 24 h and beyond after core damage, external cooling measures such as a gas vent system and an emergency containment spray backup system have been mandated. With these measures, it is difficult to completely satisfy all the requirements for proper cooling and minimized penetration and leakage while maximizing reliability and meeting the need for a passive design. Accomplishing all of these requires substantial repair and maintenance costs; thus, many difficulties can be anticipated with their implementation. This study proposes the installation of several multipod heat pipe assemblies; such an assembly includes an adiabatic region consisting of one large cylindrical structure penetrating the containment dome, a boiling region, and a condenser region consisting of many pipes that serve as the ultimate heat sink to discharge the decay heat energy from the containment with no radiation leak. Such installation will dramatically improve the nuclear safety in the event of a severe accident.
Zn based hydroxide double salts (Zn-HDS) with an interlayer spacing of 20
Å was produced by dissolving dumbbell-like ZnO crystal. The resulting Zn-HDS with a ribbon-like shape has a suitable ...morphology to explore the remarkably mild procedure for synthesis of ZnO nanobelts. We found that the intercalated water molecules into the Zn-HDS could play a key role in the ZnO nanobelts porosity. The nonporous ZnO nanobelts were successfully synthesized from the Zn-HDS by soft-solution process at 95
°C through mild dehydration agent as Na
2CO
3. As-synthesized ZnO nanobelts were grown along not only the 0
1
−1
0, but also the 2
−1
−1
0. On the other hand, the porous ZnO nanobelts were obtained from the Zn-HDS by calcinations at 200 and 400
°C. In addition, flower-like ZnO multipod and hierarchical nanostructures were produced from the Zn-HDS by using of strong dehydration agent (NaOH) through hydrothermal reaction at 150 and 230
°C.
Porous and nonporous ZnO nanobelts, multipod, and hierarchical nanostructure were successfully synthesized from Zn based hydroxyl double salts by hydrothermal reaction.
ZnO tetrapod and multipod nanostructures were synthesized by vapor-phase transport method using the mixtures of ZnO (or ZnO:In
2O
3) and graphite powders as source materials. By controlling the ...growth condition, the tetrapod whiskers with homogeneous pillar, awl and inverse-awl shaped legs, and the multipods with the similar leg shapes were obtained. Combining X-ray diffraction pattern, scanning electron microscopy, and high-resolution transmission electron microscopy image of the products in initial and final growth stages, the growth process was investigated systematically. The influences of the source, growth temperature, and vapor pressure on the final morphology were discussed by considering the surface energy of nucleus and the kinetic energy of the incoming atoms.
Multipod ZnO nanorods modified by poly (
N-vinyl-2-pyrrolidone) (PVP) were synthesized by a simple solution method. Transmission electron microscopy, ultraviolet–visible spectrum and room-temperature ...photoluminescence spectrum were used to characterize the as-prepared products. The results indicate that the multipod ZnO nanorods are composed of six pods with the wurtzite structure. Each arm of the multipod ZnO has the average diameter of 45
nm.The as-prepared product shows wide ultraviolet emission peak around 385
nm excited by Xe lamp at the room temperature.
