Science China Chemistry最新文献

Near-infrared (NIR) phosphorescence has emerged as a highly promising yet challenging research area, with potential applications in NIR optoelectronic devices, telecommunications, sensing, bioimaging, and beyond. This review discusses the exploitation of metal⋯metal (M⋯M) interactions to advance NIR phosphorescent materials, focusing on their role in enhancing photophysical properties and enabling novel applications. M⋯M interactions in closed-shell d⁸/d¹⁰ (Pt^II, Rh^I, Ni^II, Au^I) complexes offer a promising strategy to generate low-energy triplet excited states with enhanced radiative decay. This review examines recent advances in NIR phosphorescent materials driven by M⋯M interactions. We demonstrate how the triplet excited state—³MMLCT (metal-metal-to-ligand charge transfer) or a metal-centered ³[dσ*→pσ] transition—reduces HOMO-LUMO energy gaps and modulates spin-orbit coupling (SOC), enabling phosphorescent emissions beyond 700 nm. This review is categorized into two distinct design principles: the covalent “bridging ligand” approach for stable, high-performance emitters, and the supramolecular “self-assembly” strategy for stimuli-responsive, tunable luminescence. We provide insights into the structure-property relationships governing the photophysical properties, revealing how M⋯M distance, ligand rigidity, and aggregate structures dictate NIR phosphorescence. Beyond summarizingthe state of the art, this review outlines some design principles for the next generation of NIR phosphorescent materials.

Single-atom catalysts (SACs) have become the forefront of heterogeneous catalysis research due to their maximum atomic utilization rate, unique electronic structure, and excellent performance in various reactions. However, there are many challenges in the field of SACs preparation that need to be addressed. Over the past decade, leveraging our expertise in nanomaterial synthesis, our group has been exploring controllable preparation methods for SACs. We have pioneered several representative preparation strategies, establishing a robust top-down paradigm. Based on these synthetic strategies, systematic SACs have been successfully built. This review briefly introduces the unique advantages and applications of SACs, analyzes the differences between the “top-down” and “bottom-up” approaches, and comprehensively summarizes the preparation strategies of top-down SACs over the past decade. The future perspectives of top-down synthesis methods for SACs are outlined, emphasizing the creation of novel top-down techniques, the integration of multi-method combinations, and the exploration of their applications. This review aims to provide valuable insights to researchers in the field, thereby promoting the advancement and practical application of top-down synthesis strategies.

Ammonia is a cornerstone of global agriculture and chemical manufacturing, with emerging potential as a carbon-free energy carrier. However, its conventional production via the Haber-Bosch process is energy-intensive, relies heavily on fossil fuels, and results in significant CO₂ emissions. In pursuit of sustainable alternatives, renewable energy-driven synthesis routes have attracted growing interest. This review surveys recent advances in green ammonia production, covering electrocatalytic, photocatalytic, photo-electrocatalytic, and photothermal pathways, with an emphasis on the mechanistic understanding of nitrogen reduction from various feedstocks (N₂, NO₃⁻, NO₂⁻, and NO). We also highlight the critical role of in situ and operando characterization techniques in identifying active sites and reaction intermediates, as well as progress in catalyst design. By integrating mechanistic insights, analytical advances, and materials innovation, we outline key challenges and propose actionable strategies to advance scalable and sustainable ammonia synthesis.

Due to the intrinsically flexible skeletons, loose aggregation and disorder packing of organic materials, organic photovoltaic nanoparticle (OPV-NP) encounters inferior exciton dissociation and charge recombination, especially poor operational stability when applied in photocatalytic hydrogen production. To alleviate these shortages, two new acceptors were constructed by boosting 2-cantilever XZ-1 to 4-cantilever XZ-2 and 6-cantilever XZ-3, thus greatly extending the conjugated plane towards two-dimensionality. Consequently, the decreased reorganization energies, weaker exciton binding, prolonged exciton lifetimes and more ordered molecular packings were observed for 6-cantilever XZ-3, further affording an excellent hydrogen yielding rate (184.68 mmol g ⁻¹ h⁻¹). For the PM6:XZ-3 system, the hydrogen production rate was maintained at 106.1% at 40 h compared to the first 10 h of the photocatalytic hydrogenation rate. By unveiling a clear relationship of molecular spatial size-dependent photocatalytic performance, our work paves a new avenue for improving both photocatalytic activity and stability of OPV-NPs synergistically.

The rapid expansion of lithium-ion batteries in electric vehicles and grid-scale energy storage intensify the demand for sustainable recycling strategies. Traditional metallurgical recycling methods face significant challenges, including high energy consumption, environmental pollution, and inefficient critical metals recovery. In contrast, advanced direct recycling can selectively extract valuable metals while preserving cathode structure, achieving over 99% lithium recovery from lithium iron phosphate. Moreover, by directly repairing defects and crystal structures of spent materials, their electrochemical performance can be effectively restored. Due to significantly reduced energy and reagent inputs, direct recycling cuts processing costs by over 20% and reduces waste emissions by at least 40% compared to conventional methods, making it a promising low-carbon alternative. This review systematically integrates the recent advances in direct recycling of spent batteries as well as the limitations and challenges of existing technologies, and proposes future research pathways to promote resource recycling and sustainable development.

Chiral luminescent materials with multiple functions are critically significant for multimodal anti-counterfeiting systems and information encryption, but the design strategy still faces challenges. Herein, the (R-)/(S-)-QPPTZ with aggregate conformational isomerism is ingeniously designed and synthesized, exhibiting diverse photophysical properties in poly(methyl methacrylate) matrix. Quasi-equatorial (eq) conformation with highly twisted configuration exhibits enhanced intramolecular charge transfer, which leads to shorter excitation but longer emission wavelengths. The bent configuration of the quasi-axial (ax) conformation confers inverse excitation and emission behaviors. Meanwhile, the transition characters of excited states are also manipulated by the conformational configuration, in which the intersystem crossing (ISC) is effectively facilitated, assisting in the generation of triplet excitons and enabling photoactivated phosphorescence. Multiple functionalities, including excitation-dependent emission, photoactivated room-temperature phosphorescence (RTP), and circularly polarized luminescence (CPL), are simultaneously realized within the single-molecule-based system. Finally, a four-dimensional (4-D) anti-counterfeiting label is successfully demonstrated. This work not only advances the understanding of influences of molecular conformation on the molecular properties but also presents a promising strategy for multimodal anti-counterfeiting.

Seawater uranium extraction is of significant strategic importance for ensuring a continuous supply of uranium resources and the sustainable development of nuclear energy. However, the capacity, selectivity, and sustainability of this process have been notably impacted by factors such as the low concentration of uranium in seawater, the presence of complex competing ions, and inevitable marine interference. Over the past decade, substantial progress has been achieved in the development of materials and methods for uranium extraction. Notably, the electrochemical uranium extraction method has garnered widespread attention for its green, efficient, and modular development benefits. In this review, we summarize the latest advancements in the field of electrochemical uranium extraction. Firstly, we introduce the application of various electrochemical methods and different electrode materials in the extraction of uranium from seawater. Second, we analyze the mechanism of electrochemical uranium reduction and the existing new systems for uranium extraction. In the final part, we point out the limitations, challenges, and future prospects of electrochemical uranium extraction from seawater.

The deliberate and precise fabrication of supported catalysts with well-defined structures has been a long-standing pursuit. Among the large number of supports for anchoring noble metal species, layered double hydroxides (LDHs) stand out as a class of ideal supports for dispersing noble metal species due to their uniform distribution of metal sites and charge centers. However, a prerequisite for the investigation of noble metals-loaded LDHs is the construction of well-defined active sites and precisely controlled sizes of noble metal species on LDH surfaces. Based on research advances made over the past decade, we provide a detailed discussion on the fine regulation of noble metal species, including single atoms, nanoclusters, nanoparticles, and multi-site catalysts on LDHs. Furthermore, we focus on uncovering three critical aspects of noble metal-loaded LDHs: the precise location, the atomic configurations, and the interaction with the LDHs. Building upon these well-defined structures, we further clarify the structure-activity relationships of the developed materials in reactions such as hydrazine decomposition, biomass conversion, C-H bond activation, and water splitting, etc. Finally, the challenges and future directions are outlined to offer valuable insights for advancing high-activity noble metal-loaded LDHs.

Anion chemistry in electrolytes has recently attracted increasing attention due to its important role in governing solvation structure, interfacial reactions, and the formation of anion-derived electrode-electrolyte interphases. However, it remains challenging to elucidate the influence of anion coordination on the solvation dynamics and its correlation with interfacial reactions, and design principles for constructing anion-modulated solvation structures are still lacking. In this review, the coordination mechanism of anions in electrolyte solvation structures is elaborated in detail, as well as their effects on the electrochemical stability window of electrolytes, transport dynamics of solvation structures, and interfacial chemistry. We summarize universal strategies for regulating the interactions between electrolyte components to achieve anion-modulated solvation, with particular emphasis on salt design and solvent-anion interaction tuning. Furthermore, the influence of anions on the redox potential of solvation structures was correlated with interfacial behavior, while the resulting interphases and interfacial kinetics under anion chemistry are elucidated. Advances in characterization methods and their integration with simulations are also discussed, providing new opportunities for probing the dynamic evolution of anions in real time. By tuning the spotlight on anions, this review offers a unique perspective and theoretical foundation for electrolyte design for next-generation high-energy-density batteries.