Science China Chemistry最新文献

The electrosynthesis of hydrogen peroxide (H₂O₂) has been widely considered as an environmentally friendly and sustainable alternative to the conventional anthraquinone protocol. Covalent organic frameworks (COFs) have emerged as promising metal-free catalysts for oxygen reduction reaction (ORR) processes. The designable molecular structures of COFs render adjustable catalytic selectivity towards two-electron (2e⁻) ORR pathway for the electrosynthesis of H₂O₂. Here, we synthesized a viologen-linked cationic COF, namely PTBD, via Zincke reaction using a conventional solvothermal strategy. To investigate the correlation between the structure and the catalytic performance, imine-linked neutral COFs of PTBP and PBBP with varying heteroatom nitrogen contents are prepared via Schiff-base condensation reaction. Notably, the PTBD COF, which is constructed by di-cationic viologen linkages and triazine blocks, delivers an exceptional H₂O₂ selectivity of ~92%, considerably surpassing the imine-bridged neutral PTBP (~30%) and PBBP (~78%) COFs. Theoretical calculations are performed to uncover how the thermodynamic tendency of PTBD COF towards 2e⁻ ORR route is related to its proper activation of O₂. This work highlights the role of linkage and heteroatom contents in COFs regarding the catalytic selectivity, paving a way for designing metal-free catalysts for the selective electrosynthesis of H₂O₂.

The development of power conversion efficiency (PCE) for organic solar cells (OSCs) based on polymer donors with benzo[1,2-b:4,5-b′]-difuran building block is slower than that of those based on benzodithiophene due to uncontrollable aggregation behavior. However, the former is expected to be more promising in realizing environmentally friendly and high-performance devices. Thereby, a smart aggregation tuning strategy is needed for boosting the efficiency of this type of OSCs. Here we report solid additives designed by self-imitation strategy, which aims to control the aggregation of the donor D18-Fu, and regulate the domain expansion of the acceptor L8-BO. Three oligomeric additives, with or without halogenation, can uniformly reduce the energy loss and enhance charge generation compared to an additive-free control device. This improvement is demonstrated through a series of morphological characterizations, photophysical analyses and theoretical simulations, indicating strong interaction between additive molecules and donor & acceptor. As a result, a 19% PCE is reported in binary OSCs, which also represents the highest level for devices based on benzo[1,2-b:4,5-b′]-difuran core contained polymer donor. Apart from high performance, our study provides new insights into manipulating the competition between the donor and acceptor’s pure phase formation through new additive design methods.

Antibiotic pollutants have become a global environmental challenge, with tetracycline (TC) antibiotics posing a severe threat to ecosystems due to their widespread use and resistance to degradation. In this study, InVO₄ nanocrystals were synthesized using a microwave-assisted hydrothermal method. By applying a band engineering strategy, a Z-scheme heterojunction was constructed by combining InVO₄ with BiVO₄, and reduced graphene oxide (rGO) was introduced to create a BiVO₄/rGO/InVO₄ ternary photocatalyst for the efficient degradation of TC. Structural characterization and theoretical calculations indicate that the construction of the Z-scheme heterojunction facilitates the spatial separation of photogenerated charge carriers while maintaining a high redox potential of the system (with a photocurrent density of 3.46 mA/cm²). The rGO, acting as an electron transfer bridge, significantly enhances the interface charge transfer rate and material stability. The optimized ternary system exhibits degradation rate constants for TC that are 3.9 times higher than BiVO₄, 21.5 times higher than InVO₄, and 1.8 times higher than BiVO₄/InVO₄ photoanodes, maintaining stable catalytic activity after five cycles. Liquid chromatography-mass spectrometry analysis of the intermediate product evolution and toxicity assessments together verify the ecological safety of the degradation process. Density functional theory calculations combined with electron paramagnetic resonance measurements confirm that the oxidation path primarily driven by the synergistic action of h⁺, ·OH and ·O ⁻₂ radicals is the main mechanism for pollutant degradation. This study aims to develop an efficient and stable photocatalytic system by constructing a Z-scheme heterojunction composite system with a two-dimensional conductive medium, providing a theoretical basis and technical solution to address key issues such as low mass transfer efficiency and insufficient oxidation capacity in antibiotic pollution remediation.

Hydrogel-based electronic skins or triboelectric nanogenerator (TENG) are considered ideal candidates for flexible electronics. However, current hydrogels face limitations that lead to suboptimal performance, and their reliance on external power sources hampers their practical application. A two-step washing approach comprising of “salt soaking” and “salt washing” is introduced to fabricate the multifunctional hydrogel. Initially, the hydrogel framework (SAC₂Z)-acrylamide (AM) and silk fibroin (SF) hydrogel is formed via salt soaking. Subsequently, the crosslinking degree is fine-tuned by adjusting the salt ion concentration through salt washing. The obtained hydrogel SAC₂ZC possesses excellent mechanical properties (a 15-fold increase in fracture strength to 320 kPa) and excellent cold resistance up to −80 °C. Compared to conventional water-dispersible hydrogels, strain sensors based on SAC₂ZC are capable of sensing up to −30 °C. The flexible antifreeze battery based on SAC₂ZC has excellent dendrite resistance and could supply power under high pressure (30 MPa) and severe bending (180°). The SAC₂ZC-based TENG (C-TENG) enables energy harvesting, eliminating reliance on external power sources. This innovation paves the way for flexible sensing systems that integrate energy collection and storage, facilitating all-weather human-smartphone signal interaction. This research provides a new strategy to develop multifunctional SAC₂ZC hydrogel for flexible wearable devices, especially in extremely cold complex environments.

Nanomedicine has emerged as a dynamically evolving frontier in contemporary medical research. However, the development of nanomedicine is impeded by significant challenges due to its complex, multidisciplinary nature, necessitating the exploration of innovative solutions. Artificial intelligence (AI) has established itself as a pivotal and rapidly advancing domain within nanomedicine research. By leveraging its robust data processing and analytical capabilities, AI can efficiently analyze large datasets and accurately predict the properties and medical functions of nanomaterials. Over the past years, AI applications have proliferated across critical nanomedicine subdomains, including intelligent nanobiosensors for precision diagnostics, AI-optimized nanocarriers for targeted drug delivery, machine learning-guided adjuvant therapy systems, and predictive computational models for nanosafety evaluation. This review aims to provide a thorough analysis of AI’s influence throughout the entire spectrum of nanomedicine, as well as the formidable challenges and extraordinary potential for pioneering researchers.

The exposome is defined as the cumulative lifetime exposure to exogenous environmental factors and their corresponding biological responses, thereby providing a holistic framework for elucidating the complex interplay between environmental determinants and human health outcomes. Understanding these complex interactions is important for identifying the causes of diseases and associated risk factors. Recent advances in analytical methodologies employed in exposomics, including mass spectrometry and sensor-based platforms, have significantly expanded our capacity to identify and quantify both external exposures and internal biological responses. This review explores recent advancements and practical applications of these techniques in environmental health studies, with a focus on their role in detecting and characterizing complex exposure patterns. Additionally, we discuss the challenges in exposome research and propose strategies to improve its application, thereby reinforcing the potential of the exposome paradigm in advancing precision public health.

Chlorine-rich argyrodite electrolytes, despite their exceptional ionic conductivity, face critical challenges in industrial utilization of all-solid-state lithium batteries (ASSLBs) due to inherent air instability and unsatisfactory compatibility with lithium metal anodes. To solve this problem, this work doped the PO ³⁻₄ unit in Li_5.5PS_4.5Cl_1.5, yielding a modified electrolyte LPSC-5%Li₃PO₄ with significantly enhanced chemical/electrochemical stability. The integration of PO ³⁻₄ units within the bulk structure reinforces lattice stability through robust P–O bonding while inhibiting reactive sulfur species responsible for moisture-triggered H₂S generation, resulting in enhanced air/moisture stability. Moreover, the electrolyte demonstrates an ionic conductivity of 5.71 mS cm⁻¹ coupled with an exceptional critical current density reaching 2.9 mA cm⁻², indicating robust dendrite suppression capability. Notably, the PO ³⁻₄ -doped into the LPSC electrolyte induces multifaceted interfacial enhancements: a composite interphase layer consisting of LiCl and Li₃OCl phases is spontaneously formed at the lithium/electrolyte interface. Physical field simulations demonstrate that the electrolyte exhibits excellent mechanical stability, effectively suppressing the penetration of lithium dendrites. Chemically, Density functional theory calculations reveal that the electrolyte possesses a high lowest unoccupied molecular orbital potential, demonstrating good compatibility with lithium metal. This multifaced mechanism synergistically inhibits dendritic lithium growth by simultaneously passivating reactive interfaces and homogenizing ion transport dynamics. The assembled ASSLBS enables stable cycling performance, delivering an initial discharge capacity of 146.7 mAh g⁻¹ and a capacity retention of 80.0% after 1000 cycles at 0.5 C. This work establishes a straightforward and effective doping paradigm that simultaneously addresses ionic transport efficiency, air stability, and interfacial compatibility in sulfide based electrolytes. The proposed strategy provides critical insights into the rational design of high-energy-density ASSLBs with superior cyclability.

The development of advanced materials and technologies in the field of sustainability is of vital importance for addressing environmental pollution. Covalent organic frameworks (COFs) show great potential in the field of environmental remediation due to their ordered structure, high porosity, low density, large specific surface area, alongside excellent chemical stability. These features position COFs as promising candidates for environmental remediation. However, COFs usually exist in powder form with poor processability and recyclability. To overcome such challenges, the construction of COF-based aerogels with a unique three-dimensional interconnected pore structure and extremely low density is considered an important means to realize their device applications. The research on the development of advanced COF aerogel composites at the molecular level opens up a new way and provides a new choice of multifunctional materials for environmental governance. This review focuses on COF aerogels and systematically summarizes their synthesis methods and development in environmental applications.