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Encapsulating perovskite quantum dots into 3D COF for visible light-driven CO2 reduction

Science China Chemistry 2025年

作者： Xinxin Wang Yucheng Jin Xiya Yang Qingyu Luan Tianyu Wang Dongdong Qi Kang Wang Jianzhuang Jiang College of Chemistry and Materials Science Anhui Normal University Beijing Advanced Innovation Center for Materials Genome engineering Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials Department of Chemistry and Chemical Engineering School of Chemistry and Biological EngineeringUniversity of Science and Technology Beijing

Lead halide perovskite quantum dots（LHP QDs） have been revealed to possess great potential in photocatalytic applications including CO2reduction, which however suffer from poor stability. Herein, a high crystalline hydrazine-linked three-dimensional（3D） covalent organic framework, USTB-17, was fabricated from the reaction between 12-connected building block and 4-connected 3,5,7-tetrakis（4-aldophenyl）-adamantane. Post-modification with Ni2+affords the metallic framework USTB-17（Ni）followed by sequential deposition of the CH3NH2PbI3（MAPbI3） perovskite QDs into its pores, generating the USTB-17（Ni）@MAPbI3composite. Powder X-ray diffraction analysis together with theoretical simulations and transmission electron microscopy discloses the crystalline nature of USTB-17, USTB-17（Ni）, and USTB-17（Ni）@MAPbI3with an unprecedented noninterpenetrated hpt topology. The close contact of QDs inside the COF pores with the Ni catalytic site locating at the pore surface of COF allows a rapid transfer of the photogenerated electrons in QDs to the Ni catalytic sites, enhancing the photocatalytic activity for CO2reduction. This endows USTB-17（Ni）@MAPbI3with efficient photocatalysis performance for photocatalytic CO2reduction with CO generation rate of 365 μmol g-1h-1and CO selectivity up to 96% under visible-light irradiation, 7 times higher than that of USTB-17（Ni）. After four cycles of reactions, the photocatalytic CO generation rate remains almost unchanged, demonstrating its excellent cycle stability.

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Upcycling of polyethylene terephthalate to1,4-cyclohexanedimethanol in water

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Science China Chemistry 2025年

作者： Shuhui Fang Zhiwen Gao Xinrui Shi Min Zhang Wei Zhang Yue Liu State Key Laboratory of Petroleum Molecular & Process engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University engineering.Center for Sustainable Carbon Science and Technology East China Normal University Institute of Eco-Chongming

The recycling of waste polyethylene terephthalate（PET）, an extensively used polymer as plastic and fiber materials, has become an urgent topic due to the rapid generation and accumulation of plastic waste into the environment. Current chemical recycling approaches to depolymerize and convert PET into 1,4-cyclohexanedimethanol（CHDM）, an important chemical in the production of advanced polyesters, predominantly use organic solvents, such as alcohols or dioxane. Herein, we developed an environmentally friendly and economically viable pathway for converting PET to CHDM using water as the solvent. In this process, PET is sequentially hydrolyzed in water, hydrogenated to 1,4-cyclohexane dicarboxylic acid（CHDA）, and then reduced to CHDM. The PET conversion rate is self-enhanced in aqueous medium via acid-catalyzed hydrolysis by the generated CHDA intermediate. A Pd-based catalyst（e.g., Pd/C） selectively hydrogenates the arene ring of the PET monomer, terephthalic acid intermediate, and a Ru-Sn/C bimetallic catalyst reduces its COOH to CH2OH group. At optimized reaction conditions, a complete conversion of PET and 80.1% yield of CHDM are obtained. Alternatively, this approach can also efficiently produce CHDA from PET, with a yield up to 86.4%.

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DEM simulations of die filling during pharmaceutical tabletting

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Particuology 2008年第6期6卷 412-418页

作者： Chuan-Yu Wu school of chemical engineering University of Birmingham Edgbaston Birmingham B15 2TT UK

The flow behaviour of powders from a stationary shoe into a moving die, which mimics the die filling process in a rotary tablet press, was analysed using a discrete element method （DEM）, in which 2D irregular shaped particles were considered. The influence of the particle shape, size and size distribution, the number of particles used in the simulation, the initial height of powder bed in the shoe, and the filling speed on the average mass flow rate and the critical filling speed （the highest speed at which the die can be completely filled） were explored. It has been found that a maximum flow rate is obtained at the critical filling speed for all systems investigated and poly-disperse systems have higher mass flow rates and higher critical filling speeds than mono-disperse systems. In addition, the powder with particles which can tessellate generally has a lower filling rate and a lower critical titling speed.

关键词： DEM Die filling Tabletting Powder compaction Mass flow rate Critical filling speed

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Enantioselective β-alkenylation of α,β-unsaturated aldehydes via chiral biphosphine ligand modified dirhodium(II) catalysis

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Science China Chemistry 2025年

作者： Guangli Xu Hongda Chen Xiaoming Wang State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in chemical Synthesis Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences school of Chemistry and Materials Science Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences school of Chemistry and chemical engineering Henan Normal University

Dirhodium(II) complexes have achieved great success in organic synthesis,and fine-tuning their catalytic properties with various bridging ligands is well-investigated in carbene ***,combining dirhodium(II) with a sophisticated ligand as a catalyst in other reactions is still extremely challenging,especially for the asymmetric synthesis of valuable chiral ***,we report a dirhodium(II)/(S)-MeO-BIPHEP catalytic system for the challenging asymmetric β-alkenylation of α,β-unsaturated aldehydes,affording the corresponding chiral conjugate addition products in good yields with high enantioselectivities.A couple of drug-derived substrates were also compatible with the protocol,which has been successfully used to prepare biologically relevant pyranochromene *** mechanistic studies suggested that the dirhodium core might remain intact over the catalytic cycle,and the chiral diphosphine ligand plays a key role in this novel reactivity and determining the high enantioselectivities of the asymmetric conjugate addition.

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Formation and evolution of supercritical geofluid

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Science China Earth Sciences 2025年第1期68卷 39-51页

作者： Huaiwei NI Yilin XIAO Xiaolin XIONG Xiandong LIU Chunxiao GAO Yi-Xiang CHEN Yunguo LI Wan-Cai LI Xuan GUO Yang-Yang WANG Dong-Bo TAN Li ZHANG State Key Laboratory of Lithospheric and Environmental Coevolution University of Science and Technology of China Deep Space Exploration Laboratory/school of Earth and Space Sciences University of Science and Technology of China Guangzhou Institute of Geochemistry Chinese Academy of Sciences school of Earth Sciences and engineering Nanjing University State Key Lab of Superhard Materials Jilin University

In this work, we provide a comprehensive review on the formation, evolution, properties, and effects of supercritical geofluid. In Earth's interior, enhanced miscibility between H2O and silicate by the addition of special components or by the increase of pressure and temperature gives rise to supercritical geofluid with a significant amount of both H2O and silicate *** formation of supercritical geofluid in magmatic-hydrothermal systems, typified by pegmatite system, is governed by meltfluid critical curve. The formation of supercritical geofluid in metamorphic systems, typified by subducted slab, is governed by the second critical end point. Experimental results suggest that the presence of boron and fluorine in pegmatite system makes it possible to form supercritical geofluid at crustal depths, but the release of supercritical geofluid from subducted slab is withheld until almost 100 km depth. A major presence of both H2O and depolymerized structural units（monomers, dimers, etc.） endows supercritical geofluid with unique physical properties including low density, low elastic moduli, low viscosity, high diffusivity,and high electrical conductivity. Supercritical geofluid can effectively mobilize a variety of elements even including high field strength elements and heavy rare earth elements. The chemical signatures of supercritical geofluid can be inherited by metasomatized mantle and mantle-derived melts, and this could give an explanation of the oxidation of arc magmas. Phase separation of supercritical geofluid through the mechanism of spinodal decomposition leads to formation of a melt network. Multiphase fluid inclusions recovered from subduction zone rocks and pegmatites are possible relics of supercritical geofluid. Supercritical geofluid can cause electrical anomaly and low seismic velocity near the top of subducted slab, and can be linked with intermediate-focus earthquakes. Supercritical geofluid may have played a crucial role in the formation of pe

关键词： Supercritical geofluid Miscibility Subduction zone Pegmatite

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Research progress in metal-organic frameworks and their derivatives in electrochemistry

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Science China Chemistry 2025年

作者： Lingling Chen Yuxin Liu Yichun Su Wenchen Zhu Guangyu Du Huan Pang school of Chemistry and chemical engineering Yangzhou University Department of Applied Physics The Hong Kong Polytechnic University Interdisciplinary Materials Research Center Institute for Advanced Study Chengdu University State Key Laboratory of Coordination Chemistry Nanjing University

Metal-organic frameworks (MOFs) are distinguished by their unique porosity and meticulously ordered framework structures,setting them apart from conventional complexes. These materials are defined by their highly organized crystalline and pore structures, extensive surface areas, robust porosity, and superior adsorption capabilities. Owing to their exceptional structural and functional attributes, MOFs and their derivatives are leveraged across a broad spectrum of applications, demonstrating significant potential across diverse sectors. In recent times, the scientific community has increasingly focused on MOFs, underscoring their growing importance in research. Despite the promising array of applications for MOFs and their derivatives,challenges persist in practical deployments, and the pathway to research advancement remains daunting. This document delves into the synthesis and various applications of MOFs and their derivatives, particularly in the domains of energy storage, catalysis,sensing, and water treatment. It also highlights the ongoing research progress in the field of electrochemistry, including developments in lithium ion batteries (LIBs), lithium-sulfur batteries (LSBs), zinc-ion batteries (ZIBs), aqueous nickel-zinc batteries (NZBs), and supercapacitors. Finally, it provides an outlook on the future prospects and potential hurdles facing the development of MOF materials.

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Electronic structure and ultraviolet spectra of p-C_(6)H_(4)-C_(20)

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原子与分子物理学报 2025年第3期42卷 21-28页

作者： CHEN Xin school of Materials and chemical engineering West Anhui UniversityLu’an 237012China

Geometry optimization of p-C_(6)H_(4)-connected cyclo[20]carbon(p-C_(6)H_(4)-C_(20))was carried out at M062X/6-311G(d,p)level,three kinds of bond orders(Mayer,Laplacian,and Wiberg),electron-hole distributions,localized orbital locators(LOL),and infrared(IR)spectrum were also performed at the same *** on TD-DFT M062X/6-311G(d,p)method,the first 20 excited states and ultraviolet(UV)spectra of p-C_(6)H_(4)-C_(20) were *** results of π-electron delocalization analyses prove thatπ-electron delocalization of p-C_(6)H_(4)-C_(20) is more likely to occur on shorter C-C bonds rather than longer C-C bonds,and inside/outside of the ring plane rather than above/below the ring *** absorption peaks of p-C_(6)H_(4)-C_(20) locate at about 319 nm and 236 nm,respectively.

关键词： p-C_(6)H_(4)-C_(20) Bone orders UV spectrum Electron-hole analyses π-electron delocalization analyses

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Synthetic control of chiral pore surfaces in covalent organic frameworks for enantioselective separation of chiral drugs

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Science China Chemistry 2025年

作者： Shiguo Fu Xiaofeng Zhang Kaixuan Wang Linfeng Chen Fan Xia Yong Cui Yan Liu school of Chemistry and chemical engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3D chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. Density functional theory (DFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

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Microspheres trigged-stress concentration regulating piezoelectric properties of PVDF/elastomer composites

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Science China Chemistry 2025年

作者： Wenxian Zhang Jiahong Yang Qijun Sun Lu Peng Tong Lin Shouke Yan Xiaoli Sun State Key Laboratory of chemical Resource engineering Beijing University of Chemical Technology Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences State Key Laboratory of Separation Membranes and Membrane Processes School of Textile Science and EngineeringTiangong University Key Laboratory of Rubber-Plastics of Ministry of Education Shandong Provincial Key Laboratory of Rubber-PlasticsQingdao University of Science & Technology

Wearable self-powered piezoelectric pressure sensors are attracting tremendous ***,fabricating a high-sensitive elastic piezoelectric sensor for a broad response range remains ***,we assemble polar poly（vinylidene fluoride）(PVDF) microsphere-elastomer composites,achieving high-sensitive and wide-responsive pressure *** polar PVDF microspheres are produced cost-effectively through phase separation,enabling *** piezoelectric composite （PC） film demonstrates low Young’s modulus,and excellent anti-fatigue ***,the PC-based piezoelectric sensor exhibits a rather high sensitivity of 540 mV N-1in a wide sensing range （5–40 N）,240 times greater than the PVDF film-based sensor and comparable to the inorganic piezoelectric *** excellent performance is attributed to the highest average stress concentration on the spherical PVDF coupled with the remarkable deformation of dipoles of spherical PVDF in the flexible *** on excellent performance,this piezoelectric sensor achieves precise recognition of motions and sound *** high-sensitive flexible piezoelectric sensor enabling large area production with ultralow price exerts great potential in smart monitoring and intelligent robots.

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Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

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Science China Chemistry 2025年

作者： Yuan Tian Jiang-Bo Chen Jie Ying Ge Tian Yu-Xuan Xiao Yi Lu Si-Ming Wu Wei Geng Ling Shen Xiao-Yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology school of chemical engineering.and Technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

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