ACS Materials Letters最新文献

High-entropy oxides (HEOs) exhibit high catalytic activities in the O₂ evolution reaction (OER). Nevertheless, the methods used for the fabrication of these oxides necessitate the application of heat and/or pressure. Accordingly, herein, HEO colloids are produced by a facile procedure under ambient temperature and pressure conditions using a strong base, an oxidant, and metal salt(s). Using the proposed method, HEO colloids containing up to 12 metal elements are prepared and specifically tailored as electrocatalysts for the OER. This chemical approach enables the cost-effective production of HEO colloids with diverse compositions, opening the door to a wide range of applications of HEOs.

Achieving high sulfur loading and robust cycling in lithium–sulfur (Li–S) batteries under a high current density is challenging. Employing metallic catalysts to improve the charge transfer and the polysulfide lithium polysulfide (LiPSs) conversion within the sulfur cathode under a high current with a high sulfur loading represents a promising approach. This study explores metallic nickel boride (NiB) as a catalyst to enhance charge transfer and LiPS conversion. Theoretical and experimental results reveal that NiB accelerates sulfur redox kinetics, significantly improving the battery performance. With a sulfur loading of 5 mg cm^–2 cycled at 0.5 C, the NiB-based battery achieved a discharge capacity of 1239 mAh g^–1, retaining 83.2% after 150 cycles. Even at a current density of 14.89 mA cm^–2, it maintained a capacity of 590 mAh g^–1 with a low decay rate of 0.07%. This approach highlights the potential of metal boride catalysts for practical Li–S battery applications.

Constructing β-ketoenamine-linked covalent organic frameworks (COFs) for photocatalysis is highly attractive but remains challenging due to limited reaction types and monomer availability. Herein, we highlight the critical role of amino-yne click polymerization in overcoming these challenges and enabling the successful synthesis of a novel β-ketoenamine-linked COF, named En-COF-P. This new approach not only simplifies the synthesis process but also significantly expands the types of chemical linkages available for COF construction. The resulting En-COF-P exhibits an enhanced visible light absorption range, facilitating improved charge generation and separation. These properties translate into remarkable photocatalytic performance, particularly in the blue-light-driven selective oxidation of organic sulfides, where En-COF-P achieves up to 99% conversion and 99% selectivity. Remarkably, En-COF-P’s photocatalytic efficiency is eight times higher than that of traditional imine-linked COFs. This work underscores the potential of click polymerization in COF synthesis and advances a new strategy for the design of highly efficient photocatalysts.

Perovskite films with excellent photoelectric properties play a significant role in fabricating high-performance solar cells. Magnetron sputtering is a commercially available and highly reliable technique that is highly attractive for applications in the production of perovskite films. Here, the ion deposition of the step-by-step sputtering process and the continuous sputtering process was systematically explored to realize the controlled ion deposition and crystallization of sputtered perovskite films. We found that the deposition rate of organic components in the initial sputtering stage is greater than that of inorganic components, leading to the ion ratio of perovskite thin films being accurately regulated by adjusting the sputtering time. Furthermore, the injected content of methylammonium bromide will significantly affect the ion ratios and crystal structures of the sputtered perovskite films. The efficiency and stability of sputtered perovskite solar cells can be enhanced significantly by optimizing the sputtered processes and improving the crystallization, which lay a solid foundation for further study of the preparation of perovskite solar cells by magnetron sputtering.

The reference electrode (RE), integrated as a sensor within lithium-ion batteries (LIBs), offers real-time insights into the electrochemical properties of individual electrodes, which makes it an ideal indicator for monitoring the working state of LIBs. Nevertheless, most built-in REs in LIBs face significant challenges that limit their application as precise and durable sensors for effective battery management, relegating them to being rough and temporary indicators in research settings. This Review delves into the latest advances in enhancing the accuracy and longevity of lithium metal deposited on Cu (Cu-Li) REs. It explores the underlying causes and factors contributing to measurement inaccuracies. Finally, the Review puts forth strategies to overcome these challenges in three-electrode LIBs. Gaining a comprehensive understanding of the intrinsic behaviors of LIBs, REs, and their interactions is pivotal for developing high-precision REs, thereby accelerating the innovation of new and safer LIB technologies.

Coevaporation, an up-scalable deposition technique that allows for conformal coverage of textured industrial silicon bottom cells, is particularly suited for application in perovskite-silicon tandem solar cells (PSTs). However, research on coevaporated perovskites with an appropriate band gap for PSTs remains limited, with lower efficiency and reproducibility than solution-processed films. Here, we present a simple approach using a thin layer of a precursor material, namely, PbI₂, PbCl₂, CsI, or CsCl, as a seed layer on the hole-transporting layer/perovskite interface. We find CsCl to be the optimal seed layer for our system. Perovskite single junction cells prepared with CsCl seed layer exhibit 19.6% power conversion efficiency with a band gap of 1.69 eV and improved long-term stability. We attribute the observed enhancements to the more precise and consistent incorporation of the organic precursor into the perovskite lattice during the film growth. This work demonstrates that engineering the substrate surface is crucial for achieving well-controlled growth of efficient and stable coevaporated wide-band gap perovskite solar cells.

Interface engineering has significantly boosted perovskite solar cell efficiency and stability. However, numerous approaches focus on addressing defects at the interfaces between transport layers while neglecting potential issues within the bulk perovskite material. Here, a multifunctional molecule, sodium lignosulfonate (SL), containing three types of functional groups, was introduced as a chemical bridge at the perovskite/SnO₂ interface. The introduced SL bridges promote energy level alignment at the perovskite/SnO₂ interface and regulate the perovskite crystallization process. Meanwhile, the coordinated interactions between the perovskite components with −OH and −SO₃^– groups on SL, coupled with Na⁺ diffusion, effectively passivate defects at the buried interface and within the perovskite bulk. As a result, the champion SnO₂–SL based n-i-p PSC achieved power conversion efficiencies of 25.73% and 25.13% on rigid and flexible substrates, respectively. Unencapsulated devices maintained 92.9% of their initial efficiency after 2,550 h of maximum power point-tracking under 1-sun illumination in an inert atmosphere.

The synthesis of multimetal fluorides (MMFs) is challenged by the usage of toxic fluoride precursors and their thermodynamic instability at higher temperatures. Here, we demonstrate a new topochemical reaction pathway to tailor garnet-type single- and multimetal fluorides from double perovskite (DP) hosts. Our combined X-ray diffraction, Fourier-transformed infrared, and nuclear magnetic spectroscopic techniques reveal the transformation pathway as DP-(NH₄)₃(M/M′)³⁺F₆ to DP-(NH₄)₂(Na/Li)(M/M′)³⁺F₆ to garnet-Na₃Li₃(M/M′)₂F₁₂ ((M/M′)³⁺ = Al³⁺, Fe³⁺, Cr³⁺ and V³⁺) through ion-exchange reaction between NH₄⁺ and Li⁺/Na⁺ ions. The garnet MMF-Na₃Li₃(Fe_0.33Cr_0.33V_0.33)₂F₁₂ catalyst displays ultralow overpotential (η₅₀₀ of 245 mV) with higher durability.

Seawater electrolysis shows potential for sustainable hydrogen production but faces challenges from the high concentration of Cl^–, which leads to corrosion and performance degradation. In this study, we prepared a NiFe layered double hydroxide (NiFe LDH) nanoarray modified with poly(3-thiophenemalonic acid) (PTPA) on Ni foam (NiFe LDH@PTPA/NF) to enhance alkaline seawater oxidation (ASO). PTPA serves as a conductive and protective layer, improving electrical conductivity and repelling Cl^– to increase stability. The electrode demonstrated stable operation at 1000 mA cm^–2 with low overpotential for 600 h, generating minimal chlorine. In situ Raman spectroscopy confirmed that PTPA facilitates active site formation and provides Cl^– protection, while inductively coupled plasma-optical emission spectrometry analysis indicated reduced Ni and Fe leaching. This study highlights the potential of conductive polymers to enhance ASO performance and durability.

Dry-processable electrode technology presents a promising avenue for advancing lithium-ion batteries (LIBs) by potentially reducing carbon emissions, lowering costs, and increasing the energy density. However, the commercialization of dry-processable electrodes cannot be achieved solely through the optimization of manufacturing processes or modifications of existing electrode components. Therefore, material innovation is urgently required for each of the core components of dry electrodes: binders, conductive agents, and current collectors. This Review explores recent advancements in these components, delving into their physicochemical roles and contributions. We identify critical performance factors and propose design strategies aimed at improving the functionality of electrode components and the overall performance of dry electrodes. This Review provides insights into the material innovations required to overcome current limitations and drive the sustainable advancement of LIB technology through dry electrode processes.