ACS Materials Letters最新文献

One of the weakest points in organic–inorganic hybrid perovskites is their instability against light, which has puzzled the research and industry communities despite a lot of efforts conducted so far. Although how perovskites break down under light illumination has been much investigated and verified, where chemical degradation occurs in the presence of oxygen and moisture, the fundamental cause for light instability in inert conditions remains unclear. A big question with respect to device lifetime is whether a perfect encapsulation method (ideally, no penetration of moisture and oxygen) will lead to long-term stability during an actual energy-harvesting operation. If not, the fundamental cause for light-induced instability needs to be thoroughly investigated and prevented technically during device operation for their commercialization. In this Perspective, we propose the trapped charges as a fundamental cause of both intrinsic and extrinsic degradation induced by light soaking and even the ion migration observed during the degradation process based on experiments and theoretical calculations as well as revisiting previous studies on degradation. Additionally, practical techniques to suppress charge trapping in a device will be discussed for the community.

Gallium-based liquid metals (LMs) with near-room-temperature melting points have recently attracted attention due to their exceptional properties. Although attempts are starting to utilize LMs to prepare functional materials, little attention has been focused on the internal-interface of LMs and on designing chemical reactions occurring in it. Herein, a series of hydrogenation reactions are conducted in a Cu catalyst-incorporated LM to demonstrate its potential as a creative medium. Compared to the effects in an aqueous system, the hydrogenation kinetics in the LM catalytic solution is enhanced by several tens of times. The excellent catalytic performance is explained by the LM participating in a special electron-donating phenomenon with the incorporated catalyst during reaction, which is seldom reported in a common medium. The proved proton coupled electron transfer (HCET) mechanism is universal in terms of organic pollutant hydrogenation, biological platform molecule regeneration, azo-dye degradation, etc. This study provides a unique perspective for innovative design of LM catalytic systems.

In order to increase tumor tissue penetration, enhance phototherapy efficiency, and reduce off-target toxicity, we have developed a dual-locked upconversion nanoplatform (UCNP@Glu-DMMA) with a charge-reversal property for tumor-specific, cell nucleus-penetrating photodynamic therapy (PDT). The negative charge on the surface of UCNP@Glu-DMMA ensured excellent stability during blood circulation and accumulation in the tumor microenvironment (TME). Subsequently, the combined effect of the acidic TME and γ-glutamyl transpeptidase (GGT) triggered a reversal of the surface charge from negative to positive. This reversal enhanced the uptake efficiency of UCNP, leading to an increased intracellular drug concentration, deep tumor penetration, and direct nucleus delivery for the localized release of reactive oxygen species, resulting in robust DNA damage. As a result, the efficacy of PDT was significantly and precisely boosted for GGT-overexpressed tumors. This work provides a promising strategy to engineer therapeutic platforms for managing a variety of diseases based on different biomarkers.

Platinum-based chemotherapy is the cornerstone of ovarian cancer (OC) treatment. However, decrease of cellular concentration of the drug, glutathione (GSH)-mediated drug inactivation, and severe toxic side effects contribute to its clinical chemotherapy failure. Cisplatin has the ability to induce endoplasmic reticulum stress (ERS) production in OC, and sustained ERS can potentiate the cytotoxic effects of chemotherapy. Herein, platinum(IV) prodrug nanoparticles (IPD NPs) are prepared as nanocarriers of isoliquiritigenin (ISL, traditional Chinese medicine) with redox-responsive degradation properties and synergistic ERS amplification for enhanced OC treatment. Notably, IPD NPs contain docosahexaenoic acid (DHA) which enhanced cellular uptake as well as generated reactive oxygen species (ROS), thereby breaking redox homeostasis and further augmenting the effect of ERS. This current strategy of sustained ERS amplification for enhanced cisplatin-based chemotherapy overcomes the low cellular uptake, GSH-mediated drug detoxification, avoids the dose-dependent nephrotoxicity of cisplatin, and is promising for OC treatment.

We analyze practical fill factor limits across various bandgaps for single-junction perovskite solar cells, focusing on the impact of bulk charge carrier lifetime, surface recombination, and charge transport layer-induced contact resistance.

Intensive research into single-component white-light-emitting materials is extremely valuable for innovating next-generation solid-state lighting technology. Herein, we innovatively propose a crown ether-assisted supramolecular self-assembly strategy that is supported by the construction of mixed coordination units in low-dimensional hybrid metal halides (LHMHs). The resultant [(C₁₀H₂₀O₅)InCl₂]InCl₄ is an extremely rare class of zero-dimensional (0D) indium-based chloride that is featured by the structurally deformable mixed coordination units of 7-coordinated [InCl₂O₅] (In-1) and 4-coordinated [InCl₄] (In-2). Excitingly, it exhibits a high-quality white-light emission with a full width at half-maximum (fwhm) of 211 nm and a photoluminescence quantum yield (PLQY) of 33.6%, which is attributed to the unprecedented intrinsic dual self-trapped excitons (STEs) under electron–phonon coupling. The electron-transition mechanism is elucidated according to temperature-dependent PL spectra and theoretical calculations. Beyond that, the indium-based white-light emitter possesses superb water stability because of the hydrophobicity of 15-crown-5, which is unachievable for almost all LHMHs. This work sheds light on an executable self-assembly strategy for building mixed coordination units and extends to the design of single-component white-light-emitting materials.

Perovskites ABO₃ are very versatile catalysts that can change their structure in several ways to enhance their electrocatalytic properties. Among nickel-based perovskites, those containing lanthanum or alkaline earth elements at the A-site display notable potential for the oxygen evolution reaction (OER) in alkaline electrolytes. Properties of nickel-based perovskites include the formation of mixed nickel oxidation states and the remarkable ability to accommodate numerous oxygen vacancies within their lattice. Oxygen vacancy content is an effective method to boost the electrocatalytic performance, and nickelate perovskites include a fascinating family of materials that exhibit oriented lattice oxygen vacancies: the infinite layer nickelates. However, nickelate perovskites remain a relatively underexplored area of research, likely due to the challenges associate with their synthesis. A major challenge lies in understanding the dynamic self-reconstruction of nickel-based perovskites under OER conditions. Monitoring this self-reconstruction through operando characterization is essential for precisely unraveling the causes of catalyst transformation and understanding the OER mechanisms. Leveraging these findings enables the design of more effective catalysts. In this Perspective, we aim to provide a summary of recent advances, insights, and suggestions for the development of nickel-based perovskites for electrocatalytic OER in alkaline electrolytes.

Defects in perovskite oxide solid electrolytes (SEs) impact Li-ion conductivity. However, the role of oxygen vacancies (V_o) in transport behavior has been less explored. Herein, our study elucidates the microscopic origin of the role of V_o in enhancing the total ionic conductivity of a prototype lithium lanthanum titanate while maintaining its insulating properties. Scanning transmission electron microscopy and theoretical calculations reveal that the presence of V_o significantly lowers the activation energy of Li-ion migration. The V_o is revealed to be preferentially aligned parallel to c-planes and causes modulated lattice expansion in an alternating manner, resulting in easy directional Li-ion transport. The effect of V_o-assisted Li-ion transport is optimized through the hierarchical rearrangement of structural features at multiple length scales close to the direction of the V_o arrays. Our results offer novel insights into the microscopic origins of superior ion conductivity facilitated by V_o, contributing to the design of high-performance SEs.

Rechargeable manganese batteries hold promise for large-scale energy storage due to the abundance and eco-friendly nature of manganese. A key challenge is developing cathode materials capable of reversibly inserting Mn ions with a high specific capacity. Here, we demonstrate that perylene-3,4,9,10-tetracarboxylic dianhydride electrodes efficiently and reversibly insert Mn²⁺ ions in 3 M MnCl₂ aqueous electrolyte solutions. Leveraging the carbonyl groups and the π-electron configuration, such compounds can serve as robust redox centers, facilitating reversible interactions with divalent ions such as Mn²⁺. Through comprehensive studies involving electrochemistry, elemental analyses, spectroscopy, and structural analysis, we explored these systems and found them as promising anode materials for Mn batteries. Demonstrating excellent Mn storage capabilities, such molecules could attain a reversible capacity of approximately >185 mAh g^–1 at a current density of 100 mA g^–1, maintaining an average voltage of approximately 0.8 V vs Mn/Mn²⁺, while exhibiting notable capacity retention.

The practical applications of Mg metal anodes in rechargeable magnesium batteries (RMBs) have been seriously hindered due to the unstable anode interface. Herein, a simple and hyper-efficient hydrolysis of metal chloride strategy is proposed to obtain a dense layer of artificial SEI on the surface of the Mg anode. Based on the variations of relative compactness density (rρ_c), the morphology and electrochemical properties of the artificial SEI layer can be precisely regulated. Moreover, the surface-reconstructed In/MgCl₂@Mg electrode can achieve an ultralong cycle life of 1500 cycles at a current density of 3 mA cm^–2 and 1 mA h cm^–2 as well as a low overpotential (0.25 V). Consequently, a stable cycle capacity can also be maintained at 1C after 1000 cycles in full cell configurations, matching with the Mo₆S₈ cathode. This study provides a novel design concept and quantitative criteria for the specific preparation of efficient Mg anodes.