Articles in 2019

A bioinspired monstera leaf-like superwettable film with porous g-C₃N₄ nanosheets as ion-accessible channels has been developed, which shows favorable electrochemical kinetic behavior in ionic liquid electrolyte. As a proof-of-concept application, high performance flexible ionogel-based supercapacitors (FISCs) have been elaborately fabricated, which can be charged by harvesting renewable energy sources and effectively power to various portable electronics.

A new quasi 1D compound Ba₃TiTe₅ was synthesized at high pressure and high temperature, which has been evidenced to be a well-defined 1D conductor. Here, for Ba₃TiTe₅, in-situ high-pressure techniques were employed to study the emerging physics dependent on interchain hopping, such as the Umklapp scattering effect, SDW/CDW, superconductivity and non-Fermi Liquid behavior. The pressure induced superconductivity was observed. It is suggested that the appearance of superconductivity is associated with the fluctuation due to the suppression of Umklapp gap and the enhancement of T_c is related with the fluctuation of the SDW/CDW.

Synchrotron-based Bragg coherent x-ray diffraction (CXD) measurements proposed to study giant magnetorestriction in nickel NW: (a) Monochromatic X-ray beam is focused by Kirkpatrick-Baez mirrors, which creates a localized illumination on the sample (S). By rotating the sample through the Bragg condition in increments of about 0.005 degrees, CXD patterns in the vicinity of the (111) and (002) reciprocal lattice points are recorded with a two-dimensional pixelated detector. A series of diffraction patterns (collected as a function of external magnetic field H) are shown here. The interference fringes are due to the finite extent of the nanowire. The color scale is calibrated in units of X-ray photons per pixel; the center of the pattern reaches a value of 9,000, but is saturated here. (b) SQUID-hysteresis loops of a 200 nm wide and 2 micron long nickel nanowire measured with an applied field at room temperature. (c) Relative change in the lattice spacing (corresponding to the asymmetry and shift of the center of mass of the measured Bragg peaks) along the < 100 > direction and the < 110 > directions. Measurements are taken during a cyclic loading (increasing magnetic field strength) and unloading procedure.

We found high oxygen reduction reaction catalysts that are realized by ironphthalocyanine (FePc) derivatives, iron azaphthalocyanines (FeAzPcs) unimolecular layers (Fe AzUL) adsorbed on oxidized multiwall carbon nanotubes (oxMWCNTs). They showed superior ORR activities and durability than conventional FePc catalytic electrodes and commercial Pt/C. The Fe AzUL catalytic electrodes can be prepared by low-cost processing without pyrolysis, unlike other Pt-free catalytic electrodes, and are therefore promising catalytic electrode materials for applications, including polymer electrolyte fuel cells and metal–air batteries.

In this paper, we introduce a new paradigm to design scalable disordered metamaterials. We show that the localized crystallization of a semiconductor at a metal/semiconductor interface can be used as design parameter to control light interaction in such a disordered system. Here, such thermally induced crystallization, also called metal-induced crystallization, generates new zero-index states corresponding to a hybrid resonant mode emerging from selective coupling of light to the angstrom-sized crystalline shell of the semiconductor.

In this work, the large-scale growth of lateral G-h-BN heterostructure with controlled morphology together with growth mechanism have been studies. 2D h-BN lateral heterostructures with tunable morphology ranging from regular hexagon to highly symmetrical star-like is demonstrated for the first time on a liquid Cu surface by chemical vapor deposition (CVD) approach. Morphology evolution of the G-h-BN heterostructure as a function of gas flow rate and growth time is directly observed and extensively simulated based on phase field and density functional theory calculations.

Overview of up-conversion based condensed phase laser cooling of semiconductor nanostructures. Two critical parameters dictate the likelihood of realizing solid state optical refrigeration: nanostructure emission quantum yield and up-conversion efficiency. This review summarizes both parameters for existing high emission quantum yield semiconductor nanostructures such as CdSe and CsPbBr₃. CsPbBr₃ nanocrystals, in particular, possess optimal parameters for cooling, namely near unity emission quantum yields and up-conversion efficiencies up to 75%. This makes them promising materials for verifiable demonstrations of condensed phase laser cooling.

A facile in situ growth and subsequent compression strategy has been proposed to modify the separator. The in situ grown barrier layer is compact, lightweight and thin, exhibiting efficient physical/chemical entrapping capability on preventing the polysulfide shuttling. Applying this multi-functional separator, the CNT/S cathode with high sulfur content (75 wt%) delivers significantly improved long-term cycling performance with 0.056% capacity decay per cycle over 500 cycles.

The deleterious effects of climate change due to atmospheric CO₂ are being felt around the globe. To mitigate this threat, gas separation membranes possessing high CO₂ permeability and selectivity are required. We report that the morphologies and gas transport properties of dense polymer membranes composed of a midblock-sulfonated block polymer are sensitive to casting solvent and relative humidity. We further establish that submersion of these membranes in liquid water alters the membrane morphology and improves CO₂ permeability and CO₂/N₂ selectivity, with CO₂ permeabilities and CO₂/N₂ selectivities reaching 482 Barrer and 57, respectively. These membranes are therefore promising for CO₂ capture.

An intriguing model system of flexible and transparent luminescent epitaxial thin film with highly tunable photoluminescence response is demonstrated by using the mica as substrate. The purely mechanical strain, instead of electric field, control of photoluminescence properties with superior stability, reversibility, and antifatigue behaviors shows promising applications in next-generation lightweight, transparent, flexible, and wearable passive optical devices.

The scheelite-type DyCrO₄ shows a large linear magnetoelectric effect (magnetic field induced electric polarization) as well as the converse effect (electric field induced magnetization) within ± 3 T. A higher magnetic field induces a metamagnetic transition from the initially collinear antiferromagnetic structure to a canted one, generating a giant ferromagnetic component by about 7 μB f.u.⁻¹. The new spin structure can break the spatial inversion symmetry and yield spontaneous ferroelectric polarization, giving rise to the coupling of ferromagnetism and ferroelectricity in a single-phase material.

Mass spectrometry, coupled with soft ionization methods, in conjunction with associated techniques such as tandem mass spectrometry, ion mobility and spectroscopies of sorts, has become a powerful tool for the characterization of advanced materials.

This study highlights a new methodology to develop electrical property of CeO₂ without doping based on characteristic surface defects. The CeO₂ surface approach presented in this work addresses the electrolyte material challenge faced by solid state oxide fuel cells (SOFCs) over 100 years. In our approach, we take advantage of the energy band structure and surface defect to develop new functional electrolyte material based on non-doped ceria. The oxygen vacancies and defects in surface state of the CeO₂ result in new electrical and band properties, thus giving rise in superionic conduction for successful SOFCs application.

An asymmetric Janus adhesive tape with lightly-crosslinked PDMS acting as adhesive layer, highly-crosslinked PDMS functioning as supporting layer has been prepared through an interfacial hydrosilylation strategy. Without any laborious replicating structure preparation and molecular design, this Janus adhesive tape shows good wet/dry amphibious adhesion.

A direct synthesis method for high-quality MoS₂ thin films on p-Si wafer is reported herein. To increase the hydrophilicity of the p-Si wafer, MoO₃ was deposited before spin-coating. The (NH₄)₂MoS₄ precursor was easily coated onto the MoO₃/p-Si and was converted to a MoS₂/p-Si heterojunction via thermolysis. This method has the potential to be used in 2D electronic device fabrication in the future.

Inspired from Ca²⁺-induced Ca²⁺ release process responsible for Ca²⁺ channel and muscle contraction, a smart Ca²⁺ self-regulated nanochannel system is constructed by the convergence of a Ca²⁺-responsive polymer with porous anodic alumina membrane. Dynamic gating behavior of the nanochannel could be precisely modulated by Ca²⁺ concentration utilizing remarkable conformational transition of the copolymer chains from globule to coil.

Amputees with prosthetic hands face challenges accomplishing ordinary tasks in daily life. An optimal set of materials, design layouts, and assembly schemes is presented for the construction of stretchable sensor circuits on an easy-to-wear rubber glove, allowing for the seamless integration with arbitrary prosthetic hands. A wristwatch unit provides the ability for both real-time display and post-analysis of the measured signals, enabling efficient interactions with the users. A precisely engineered soft packaging layer offers realistic human hand-like appearance, physical attributes, and warmth, thereby promoting its potential applications in more natural integration of prosthetic hand users into many social settings.

Rhombohedral (gray) arsenic represents a promising layered material for the fabrication of electronic devices and sensors; however, synthetic protocols for tuning its properties or protecting the surface by covalent functionalization are not known. In this communication, we present its covalent functionalization accompanied by exfoliation of rhombohedral arsenic in the presence of chromium hexacarbonyl and UV irradiation. Under such conditions, arsenic atoms act as ligands to the chromium metal center. We believe that this approach will open the doors for next modifications of rhombohedral few-layer arsenic and enable its application in variable fields including electronic devices, sensors, and energy devices.

We demonstrate an aligned array of helical nanostructures via the Weigert effect, which can be used in patternable and reversible structural color reflectors. To the best of our knowledge, this is the first demonstration of a photolithography technique applied to a perfectly orientationally ordered medium, here liquid crystal material, itself; the mechanism is connected to the chiral optics.

Given the current needs for lasers on flexible substrates or as disposable, low-cost appliances, solution-processable lasers based on tunable colloidal quantum dots (QD) could revolutionize the field of laser-based opto-electronics, much as these QD materials currently do for the growing markets of displays and lighting. In this perspective, we present the status of this rapidly advancing field, followed by a discussion of the remaining challenges and possible avenues for future research and valorization.