Critical Role of Tetrahedral Coordination in Determining the Polysulfide Conversion Efficiency on Spinel Oxides.

Understanding the structure-property relationship and the way in which catalysts facilitate polysulfide conversion is crucial for the rational design of lithium-sulfur (Li-S) battery catalysts. Herein, a series of NiAlO, CoAlO, and CuAlO spinel oxides with varying Ni, Co, or Cu tetrahedral and octahedral site occupancy are studied as Li-S battery catalysts. Combined with experimental and theoretical analysis, the tetrahedral site is identified as the most active site for enhancing polysulfide adsorption and charge transfer.

Electrically Generated Exciton Polaritons with Spin On-Demand.

Generation and manipulation of exciton polaritons with controllable spin could deeply impact spintronic applications, quantum simulations, and quantum information processing, but is inherently challenging due to the charge neutrality of the polariton and the device complexity it requires. Here, electrical generation of spin-polarized exciton polaritons in a monolithic dielectric perovskite metasurface embedded in a light-emitting transistor is demonstrated. A finely tailored interplay of in- and out-of-plane symmetry breaking of the metasurface allows to lift the spin degeneracy through the polaritonic Rashba effect, yielding high spin purity with normalized Stokes parameter of S ≈ 0.

Cation Migration-Induced Lattice Oxygen Oxidation in Spinel Oxide for Superior Oxygen Evolution Reaction.

Activating the lattice oxygen can significantly improve the kinetics of oxygen evolution reaction (OER), however, it often results in reduced stability due to the bulk structure degradation. Here, we develop a spinel FeCoCrO with active lattice oxygen by high-throughput methods, achieving high OER activity and stability, superior to the benchmark IrO. The oxide exhibits an ultralow overpotential (190 mV at 10 mA cm) with outstanding stability for over 170 h at 100 mA cm.

Correction: High-performance one-dimensional halide perovskite crossbar memristors and synapses for neuromorphic computing.

Correction for 'High-performance one-dimensional halide perovskite crossbar memristors and synapses for neuromorphic computing' by Sujaya Kumar Vishwanath , , 2024, , 2643-2656, https://doi.org/10.1039/D3MH02055J.

Understanding the Mechanisms of Methylammonium-Induced Thermal Instability in Mixed-FAMA Perovskites.

Despite a recent shift toward methylammonium (MA)-free lead-halide perovskites for perovskite solar cells, high-efficiency formamidinium lead iodide (FAPbI) devices still often require methylammonium chloride (MACl) as an additive, which evaporates away during the annealing process. In this article, it is shown that the residual MA, however, triggers thermal instability. To investigate the possibility of an optimal concentration of MA that may improve thermal stability, the intrinsic thermal stability of pure FA, FA-rich, MA-rich, and pure MA perovskite films (FAMAPbI, FAMA) is studied.

Retinomorphic Color Perception Based on Opponent Process Enabled by Perovskite Bipolar Photodetectors.

The ability to perceive color by the retina can be attributed to both its trichromatic photoreceptors and the antagonistic neural wiring known as the opponent process. While neuromorphic sensors have been shown to demonstrate memory and adaptation capabilities, color perception is still challenging due to the intrinsic lack of spectral selectivity in narrow bandgap semiconductors. Furthermore, research on emulating neural wiring is severely lacking.

Allotrope-dependent activity-stability relationships of molybdenum sulfide hydrogen evolution electrocatalysts.

Molybdenum disulfide (MoS) is widely regarded as a competitive hydrogen evolution reaction (HER) catalyst to replace platinum in proton exchange membrane water electrolysers (PEMWEs). Despite the extensive knowledge of its HER activity, stability insights under HER operation are scarce. This is paramount to ensure long-term operation of Pt-free PEMWEs, and gain full understanding on the electrocatalytically-induced processes responsible for HER active site generation.

High-performance one-dimensional halide perovskite crossbar memristors and synapses for neuromorphic computing.

Despite impressive demonstrations of memristive behavior with halide perovskites, no clear pathway for material and device design exists for their applications in neuromorphic computing. Present approaches are limited to single element structures, fall behind in terms of switching reliability and scalability, and fail to map out the analog programming window of such devices. Here, we systematically design and evaluate robust pyridinium-templated one-dimensional halide perovskites as crossbar memristive materials for artificial neural networks.

Floquet Engineering of Excitons in Two-Dimensional Halide Perovskites via Biexciton States.

Layered two-dimensional halide perovskites (2DHPs) exhibit exciting non-equilibrium properties that allow the manipulation of energy levels through coherent light-matter interactions. Under the Floquet picture, novel quantum states manifest through the optical Stark effect (OSE) following intense subresonant photoexcitation. Nevertheless, a detailed understanding of the influence of strong many-body interactions between excitons on the OSE in 2DHPs remains unclear.

Surface engineering for stable electrocatalysis.

In recent decades, significant progress has been achieved in rational developments of electrocatalysts through constructing novel atomistic structures and modulating catalytic surface topography, realizing substantial enhancement in electrocatalytic activities. Numerous advanced catalysts were developed for electrochemical energy conversion, exhibiting low overpotential, high intrinsic activity, and selectivity. Yet, maintaining the high catalytic performance under working conditions with high polarization and vigorous microkinetics that induce intensive degradation of surface nanostructures presents a significant challenge for commercial applications.

Transition metal dichalcogenide-based materials for rechargeable aluminum-ion batteries: A mini-review.

Rechargeable aluminum-ion batteries (AIBs) have emerged as a promising candidate for energy storage applications and have been extensively investigated over the past few years. Due to their high theoretical capacity, nature of abundance, and high safety, AIBs can be considered an alternative to lithium-ion batteries. However, the electrochemical performance of AIBs for large-scale applications is still limited due to the poor selection of cathode materials.

Balanced NO and Proton Adsorption for Efficient Electrocatalytic NO to NH Conversion.

Electrocatalytic nitrate (NO)/nitrite (NO) reduction reaction (eNORR) to ammonia under ambient conditions presents a green and promising alternative to the Haber-Bosch process. Practically available NO sources, such as wastewater or plasma-enabled nitrogen oxidation reaction (p-NOR), typically have low NO concentrations. Hence, electrocatalyst engineering is important for practical eNORR to obtain both high NH Faradaic efficiency (FE) and high yield rate.

Tuning Main Group Element-based Metal-Organic Framework to Boost Electrocatalytic Nitrogen Reduction Under Ambient Conditions.

Main group element-based materials are emerging catalysts for ammonia (NH ) production via a sustainable electrochemical nitrogen reduction reaction (N RR) pathway under ambient conditions. However, their N RR performances are less explored due to the limited active behavior and unclear mechanism. Here, an aluminum-based defective metal-organic framework (MOF), aluminum-fumarate (Al-Fum), is investigated.

Ion-Mediated Recombination Dynamics in Perovskite-Based Memory Light-Emitting Diodes for Neuromorphic Control Systems.

Neuromorphic devices can help perform memory-heavy tasks more efficiently due to the co-localization of memory and computing. In biological systems, fast dynamics are necessary for rapid communication, while slow dynamics aid in the amplification of signals over noise and regulatory processes such as adaptation- such dual dynamics are key for neuromorphic control systems. Halide perovskites exhibit much more complex phenomena than conventional semiconductors due to their coupled ionic, electronic, and optical properties which result in modulatable drift, diffusion of ions, carriers, and radiative recombination dynamics.

Essential role of lattice oxygen in methanol electrochemical refinery toward formate.

Developing technologies based on the concept of methanol electrochemical refinery (e-refinery) is promising for carbon-neutral chemical manufacturing. However, a lack of mechanism understanding and material properties that control the methanol e-refinery catalytic performances hinders the discovery of efficient catalysts. Here, using O isotope-labeled catalysts, we find that the oxygen atoms in formate generated during the methanol e-refinery reaction can originate from the catalysts' lattice oxygen and the O-2p-band center levels can serve as an effective descriptor to predict the catalytic performance of the catalysts, namely, the formate production rates and Faradaic efficiencies.

Graphene Enhances the Loading Capacity and Lubrication Performance of Ionic Liquids: A Molecular Dynamics Study.

Ionic liquid (IL) combined with graphene additives have garnered extensive attention in the field of high-performance lubricating materials. However, the ambiguous mechanism of graphene influencing the load-carrying and anti-wear capacity of ILs needs further study. In this work, friction simulation shows that adding graphene causes friction coefficient to reduce by up to 88% compared with pure ILs, but lubrication performance is lost due to the destruction of graphene under high stress.

Insights to Carrier-Phonon Interactions in Lead Halide Perovskites via Multi-Pulse Manipulation.

A fundamental understanding of the hot-carrier dynamics in halide perovskites is crucial for unlocking their prospects for next generation photovoltaics. Presently, a coherent picture of the hot carrier cooling process remains patchy due to temporally overlapping contributions from many-body interactions, multi-bands, band gap renormalization, Burstein-Moss shift etc. Pump-push-probe (PPP) spectroscopy recently emerges as a powerful tool complementing the ubiquitous pump-probe (PP) spectroscopy in the study of hot-carrier dynamics.

Carriers, Quasi-particles, and Collective Excitations in Halide Perovskites.

Halide perovskites (HPs) are potential game-changing materials for a broad spectrum of optoelectronic applications ranging from photovoltaics, light-emitting devices, lasers to radiation detectors, ferroelectrics, thermoelectrics, etc. Underpinning this spectacular expansion is their fascinating photophysics involving a complex interplay of carrier, lattice, and quasi-particle interactions spanning several temporal orders that give rise to their remarkable optical and electronic properties. Herein, we critically examine and distill their dynamical behavior, collective interactions, and underlying mechanisms in conjunction with the experimental approaches.

Recent Advances in Metal-Organic Framework-Based Nanomaterials for Electrocatalytic Nitrogen Reduction.

The production of ammonia under moderate conditions is of environmental and sustainable importance. The electrochemical nitrogen reduction reaction (E-NRR) method has been intensively investigated in the recent decades. Nowadays, the further development of E-NRR is largely hindered by the lack of competent electrocatalysts.

Directional Emission from Electrically Injected Exciton-Polaritons in Perovskite Metasurfaces.

We present a new approach to achieving strong coupling between electrically injected excitons and photonic bound states in the continuum of a dielectric metasurface. Here a high-finesse metasurface cavity is monolithically patterned in the channel of a perovskite light-emitting transistor to induce a large Rabi splitting of ∼200 meV and more than 50-fold enhancement of the polaritonic emission compared to the intrinsic excitonic emission of the perovskite film. Moreover, the directionality of polaritonic electroluminescence can be dynamically tuned by varying the source-drain bias, which induces an asymmetric distribution of exciton population within the transistor channel.

Edges of Layered FePSe Exhibit Increased Electrochemical and Electrocatalytic Activity Compared to Basal Planes.

Transition metal trichalcogenphosphites (MPX), belonging to the class of 2D materials, are potentially viable electrocatalysts for the hydrogen evolution reaction (HER). Many 2D and layered materials exhibit different magnitudes of electrochemical and electrocatalytic activity at their edge and basal sites. To find out whether edges or basal planes are the primary sites for catalytic processes at these compounds, we studied the local electrochemical and electrocatalytic activity of FePSe, an MPX representative that was previously found to be catalytically active.

Perovskite quantum dot one-dimensional topological laser.

Various topological laser concepts have recently enabled the demonstration of robust light-emitting devices that are immune to structural deformations and tolerant to fabrication imperfections. Current realizations of photonic cavities with topological boundaries are often limited by outcoupling issues or poor directionality and require complex design and fabrication that hinder operation at small wavelengths. Here we propose a topological cavity design based on interface states between two one-dimensional photonic crystals with distinct Zak phases.

Pd-PdO Nanodomains on Amorphous Ru Metallene Oxide for High-Performance Multifunctional Electrocatalysis.

Developing highly efficient multifunctional electrocatalysts is crucial for future sustainable energy  pursuits, but remains a great challenge. Herein, a facile synthetic strategy is used to confine atomically thin Pd-PdO nanodomains to amorphous Ru metallene oxide (RuO ). The as-synthesized electrocatalyst (Pd RuOx-0.