Hongbin Zhang

Developing effective electrocatalysts to suppress lithium polysulfides (LiPSs) shuttling and accelerate the sluggish sulfur redox reaction (SRR) remains challenging for lithium‐sulfur batteries (LSBs). The multistep 16‐electron SRR requires not only strong polysulfides conversion capability but also sustained interfacial electron supply. Herein, we report a MOF‐derived catalytic site and Schottky barrier dual‐engineered semiconductor‐metal heterostructure, denoted DSMH@C, to couple polysulfides catalysis with low‐barrier‐potential electron injection. In DSMH@C, oxygen‐deficient semiconducting In ₂ O _3‐x provides vacancy‐associated catalytic sites that strengthen LiPSs chemisorption and d‐p orbital hybridization with sulfur species, while metallic In serves as an electronically coupled transport domain. More importantly, the defect states in In ₂ O _3‐x regulate the energy band and depletion region at the In/In ₂ O _3‐x heterointerface, lowering the electron‐injection barrier potential from metallic In to the semiconducting catalytic domain. This dual engineering enables efficient polysulfides conversion with timely electron supply, accelerating SRR kinetics and suppressing LiPSs shuttling. Consequently, DSMH@C delivers 998 mAh g ⁻¹ at 1 C, a low capacity decay rate of 0.038% per cycle over 500 cycles, an areal capacity of 11.1 mAh cm ⁻² at 10 mg cm ⁻² sulfur loading, and a pouch‐cell energy density of 507.5 Wh kg ⁻¹ .

We present an approach for first principles investigations on the spin-driven electric polarization in type II multiferroics. We propose a parametrization of the polarization with the parameters calculated using the Korringa-Kohn-Rostoker Green's function (KKR-GF) formalism. Within this approach the induced electric polarization of a unit cell is represented in terms of three-site parameters. Those antisymmetric with respect to spin permutation are seen as an based counterpart to the phenomenological parameters used within the inverse-Dzyaloshinskii-Moriya-interaction (DMI) model. Due to their relativistic origin, these parameters are responsible for the electric polarization induced in the presence of a noncollinear spin alignment in materials with a centrosymmetric crystal structure. Beyond this, our approach gives direct access to the element- or site-resolved electric polarization. To demonstrate the capability of the approach, we consider several examples of the so-called type II multiferroics, for which the magnetoelectric effect is observed either as a consequence of an applied magnetic field (we use Cr 2 O 3 as a prototype), or as a result of a phase transition to a spin-spiral magnetic state, as for instance in MnI 2 , CuCrO 2 , and AgCrO 2 .

Enhancing dielectric energy-storage density ( U _e ) requires maximizing the difference between maximum and remanent polarizations (Δ P ). Improving Δ P remains fundamentally challenging, as existing strategies rarely achieve simultaneous high maximum polarization and low remanent polarization. We introduce a postsynthesis treatment method, cryogenic thermal cycling, in which liquid nitrogen infiltrates the film and then is rapidly cycled to 100°C. This process markedly increases Δ P to 105 microcoulombs per square centimeter in oxide ferroelectric titanate films through oxygen vacancy–mediated nitrogen hybridization. Using this approach, we increased U _e to 261 joules per cubic centimeter with an efficiency approaching 80%. This approach is broadly applicable to diverse film materials with thicknesses spanning the nano- to microscale, offering a facile and cost-effective route to overcoming the critical bottleneck in Δ P and U _e .

In this article, a novel nonintrusive stereo coaxial bitelecentric imaging system is designed for detecting crystal size distribution (CSD) during various crystallization processes. The stereo microvision system includes coaxial bitelecentric lenses with tunable numerical aperture, which can acquire the maximal common focus area for snapshotting binocular images. A new design of collimated backlight illumination is presented to facilitate snapshotting high-contrast particle images with regard to the imaging background. Moreover, an in situ calibration method is developed for the binocular imaging system to facilitate in situ measurement subject to a very limited space for installation outside a crystallizer, which can acquire reliable solutions for all camera parameters to avoid the telecentric vision ambiguity problem. In addition, a dense stereo reconstruction of microparticle shape is offered for the accurate measurement of each microparticle size in 3-D space. An in situ measurement test on a calibration target inserted into a glass tube validates the proposed stereo imaging scheme and calibration method, demonstrating a low reprojection error smaller than 0.17 pixel. Experiments on detecting the length distribution of L-glutamic acid crystal population in a glass tube and a continuous-flow crystallizer verify a significant reduction on the measurement error on CSD compared with the recent methods, corresponding to a relative error smaller than 2%.

We report the use of Fe–Ag bimetallic nanoparticles supported on α-Al₂O₃ as tunable highly active and selective catalysts for the semihydrogenation of acetylene in ethylene rich streams. The addition of silver enhances the ethylene selectivity. Experimental evidence was supported by DFT calculations predicting Gibbs free energies and adsorption energies as a function of catalyst composition. Comprehensive characterization was carried out using ICP, XRF, XRD, N₂-physisorption, TPR, STEM-EDX, and XPS. This work is inspired by the need for more sustainable catalysts beyond Pd for the removal of trace amounts of acetylene from the ethylene under front-end conditions downstream of industrial steam crackers for olefin production. Conventional Pd-based catalysts, though highly active, suffer from limited selectivity, high cost, and environmental concerns. Iron emerges as a sustainable alternative due to its abundance, low toxicity, and favorable hydrogenation activity. Incorporation of silver into iron catalysts leverages synergistic effects that allow to tune the performance of the catalysts. These effects result in enhanced catalytic activity and improved selectivity towards ethylene. The present work demonstrates a promising approach for developing cost-effective, sustainable, and highly active catalysts for industrial acetylene hydrogenation.

Permanent magnets draw their properties from a complex interplay of chemical composition and phase, each with their associated intrinsic magnetic properties. Gaining an understanding of these interactions is the key to deciphering the origins of a permanent magnets’ magnetic performance and facilitate the engineering of much improved-performing magnets. Here, we use advanced multiscale microscopy and microanalysis on a bulk Sm ₂ (Co,Fe,Cu,Zr) ₁₇ pinning-type high-performance magnet with outstanding thermal and chemical stability. Comparison of the microstructure in regions of different composition, we demonstrate that the pinning of magnetic domains, imaged by nanoscale magnetic induction mapping, is controlled by the composition and atomic arrangement of copper. This is confirmed by micromagnetic simulations. Contrary to the belief that grain boundaries are “weak links” in magnetic materials, we demonstrate grain boundaries undergo magnetization reversal at relatively low fields (0.1-0.3 T), but this remains confined to these regions and does not significantly impact the magnet’s coercivity. Our results showcase that it is the optimal microstructure within the grain itself that is crucial for achieving the desired magnetic properties.