Journal of the American Chemical Society
·
2023
·
IF 15
Shang Shi,Zhenzhen Shen,Shanshan Li,Qian Wang,Rui Wen,Bing Liu
The use of carbon materials in porous electrodes has impressive advantages. However, precisely tailoring the multilevel pore structure of carbon electrodes remains an unsolved challenge. Here, we report a highly efficient site-selective growth strategy to synthesize colloidal carbon rings by templating patchy droplets. Carbon rings are used for the direct fabrication of self-standing porous electrodes with hierarchical pores for lithium–oxygen batteries (LOBs). In situ atomic force microscopy reveals that during discharge the discharge products densely nucleate and grow on carbon rings, demonstrating that such rings are a very potential electrode material in LOBs. The hollow carbon ring electrode (HCRE) possesses micrometer-scale channels formed by random packing of rings and nanochannels consisting of ring-shaped hollow cavities connected by nanosized pores in the wall. Both channels contribute to ion transportation and gas diffusion, but the storage of the discharge products mainly lies in micrometer-scale channels, leading to a high discharge capacity of LOBs (20 658 mAh/g). Our work paves a new way to construct hierarchically porous electrodes for application in electrocatalysis and electrochemical energy storage.
研究领域:
材料科学
·
电化学能源存储
✓ 已验证
DOI
高影响因子
CHEMIE INGENIEUR TECHNIK
·
2021
·
IF 1.672
Shu Wang,Xiaopeng Wang,Yanhang Huang,Lingyong Zeng,Yiyi He,Mebrouka Boubeche,Huixia Luo
Previously unreported Ce 0.9 Pr 0.1 O 2- δ -Pr 0.6 Ca 0.4 MnO 3- δ (CPO-PCMO) dual-phase membrane is designed and successfully fabricated. The crystal structure, surface morphology, stability, and oxygen permeability is systematically investigated. The XRD results reveal that CPO-PCMO dual-phase membranes are made up of cubic fluorite phase and orthorhombic perovskite phase, which exhibit excellent stability at elevated temperature under air atmospheres as well as various low oxygen conditions such as Ar or CO 2 atmospheres. In addition, no obvious holes, cracks, and impurities are observed. The obtained CPO-PCMO membrane with 0.8 mm thickness exhibits comparable oxygen permeability with a flux of 0.23 mL min −1 cm −2 under air/He gradient at 1000 °C and stably works over 300 min without obvious deterioration under air/CO 2 gradient, suggesting it has good CO 2 stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2025
·
IF 3.3
Chaonan Wang,Kaixuan Guo,Zhonghan Cheng,Chongli Wang,Duozhen Chai,Dongfeng Cao,Ye Yuan,Somboon Chaemchuen
Metal-organic frameworks (MOFs) with ZIF-67 have been widely studied. Incorporating multi-bimetals into ZIF-67 offers a strategic approach to leverage unique properties and address the limitations of traditional single-metal in ZIF-67. An environmentally friendly solid-state thermal (SST) method to simultaneously incorporate heterometals (Cu, Fe, Ru, Pd, Mn, and Ni) into the ZIF structure, referred to as M@ZIF-67, is developed. The synthesis occurs in a single step, utilizing thermally-treated mixed solid precursors of multi-bimetals and imidazole ligands without additional agents or solvents, which is the innovative green route to approach multi-bimetals ZIFs. Multiple techniques confirm that heterometals are homogeneous, uniform, and precised metal content in the iso-structure of ZIF-67. Interestingly, synthesizing M@ZIF-67 through the SST method achieves a scalable and high yield. Furthermore, the M@ZIF-67 exhibits a precise heterometal content, which plays a crucial role in enhancing the catalytic performance of CO2 cycloaddition, surpassing results obtained through traditional ZIF-67.
研究领域:
材料科学
·
化学工程
·
环境科学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Bin Jiang,Congcong Zhang,Na Yang,Qi Zhou,Longfei Zhang,Jingshuai Li,Wei Yang,Xiaodong Yang,Luhong Zhang
Developing highly active photocatalysts that can directly utilize clean, cheap, and sustainable solar energy to achieve an efficient carbon dioxide (CO2) cycloaddition reaction under mild reaction conditions (1 bar of CO2) remains a great challenge. In this paper, 2D/2D ZnIn2S4/Zn-NC S-scheme heterojunction composites were constructed by the in situ growth of layered ZnIn2S4 on the surface of two-dimensional (2D) ZIF-L-derived Znδ+ (0 ≤ δ ≤ 2) and N codoped carbon skeletons (Zn-NC-T) via a low-temperature solvothermal method. The optimized ZnIn2S4/Zn-NC-T photocatalysts exhibited favorable photocatalytic CO2 cycloaddition performance, and the yield of cyclic carbonate reached about 98.8% under 10 mmol epoxides reactant, 1 bar CO2 pressure, and full-spectrum irradiation for 4 h. The favorable photocatalytic performance is attributed to the efficient photothermal conversion and effective separation of photogenerated carriers induced by the carbon matrix and heterojunctions, respectively. In addition, the stability of the heterojunction structure and activity were demonstrated through cyclic experiments. Furthermore, the possible mechanism of S-scheme heterojunction photocatalytic CO2 cycloaddition is proposed through electron paramagnetic resonance (EPR) spectra, cyclic voltammetry (CV) experiments, and quenching experiments. The mechanism analysis proved that light irradiation is conducive to the transfer of photogenerated electrons from the conduction band of ZnIn2S4 to epoxides, promoting the formation of ring-opening intermediates, and photogenerated holes may promote the coordination and polarization of adsorbed epoxides. This work not only prepared an S-scheme heterojunction catalyst with excellent photocatalytic CO2 cycloaddition performance but also provided new insights for the rational design of heterojunction catalysts for photocatalytic CO2 cycloaddition.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
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2021
·
IF 4.641
Ling Zhou,Kan Hu,Tengguo Dong,Qian Wang,Hengming Huang,Chunhua Lu,Jiahui Kou,Zhongzi Xu
Copolymerization is an efficient method to modulate the intrinsic properties of graphitic carbon nitride (g-C 3 N 4 ). Herein, carbon ring and stereo molecular scaffold co-doped g-C 3 N 4 heterostrcutural nanosheets are constructed for simultaneously enhanced photocatalytic hydrogen evolution under ordinary pressure. The carbon ring changes the in-plane connection of g-C 3 N 4 by the sp 2 -hybridized C N bonds, extending the delocalization of π electrons. The stereo molecular scaffold loses the interlayer stacking of bulk g-C 3 N 4 for easier exfoliation. The synergistic effect of the above two aspects can greatly improve the photocatalytic performance of AGCN. After thermal exfoliation, the highest photocatalytic hydrogen generation activity of A 0.2 G 0.3 CN-E sample is 12.9 times higher than that of MCN. This work provides a strategy to design g-C 3 N 4 photocatalysts with enhanced photocatalytic activity by using synergistic effect.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qifeng Chen,Guoming Gao,Hongpian Guo,Shen-Ao Wang,Qingqing Wang,Yanfen Fang,Xun Hu,Ran Duan
The photocatalytic overall water-splitting to generation hydrogen and oxygen over polymeric carbon nitrides is highly crucial in green energy usages and industry applications. To promote the separation efficiency of photoinduced charge carriers and adjust the band structure of polymeric carbon nitrides (PCNs), boron doped PCN modified with carbon-ring (CR) and carbonyl was synthesized via a polymerization of melamine with boric acid and benzoic acid. The combination of doped boron atom into the heptazine structure by displacing a carbon atom with the introduction of CR conjugated to the carbon atom in heptazine unit regulated the band structure, electronic structure, and delocalized the distribution of electrons, leading to improved separation and transfer of charge carriers photoinduced. Moreover, experimental results combined with density functional theory (DFT) calculations proved that the introduced polar groups, carboxyl, facilitated the adsorption of water molecules and promoted the photocatalytic hydrogen evolution. Importantly, the CR in-situ formed promoted the photocatalytic dioxygen evolution. The combined effect of doped boron, CR modification and carboxyl group endowed the improved the photocatalytic overall water-splitting activity. This work provides an avenue for the synthesis of metal-free photocatalysts with improved overall water-splitting activity via the combination of heterogeneous atom doping and construction of delocalized π-conjugated structures and polar group modification.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 33
·4812-4821
·
IF 5.582
Yudi Feng,Ke Jin,Jia Guo,Changchun Wang
The development of the modern microelectronic industry calls for low permittivity interlayer dielectric materials with excellent thermal stabilities, robust mechanical strength and matching processability. Traditionally, it is difficult to fabricate materials with low k values, high heat endurance, high modulus and good processability simultaneously. Herein, we prepared two novel hydrocarbon precursors with dibenzocyclooctene (DBCOD) and thermo-crosslinkable benzocyclobutene (BCB) units by group transformation and cross-coupling reactions. These precursors can be cured at elevated temperatures to give crosslinked all-aliphatic/aromatic-ring structures. The low-polarizable hydrocarbon skeletons possess low dielectric constants (Dk = 2.66/2.54, respectively) and superior hydrophobicity (high water contact angle of ∼113°/125° and low water uptake of 0.10%/0.37%). Moreover, the rigid crosslinked cyclic structures render significantly high thermostability and mechanical modulus, such as very high glass transition temperatures (Tg > 380 °C/369 °C), high 5% weight loss temperatures (Td,5% = 499 °C/492 °C), low coefficient of thermal expansion of 41.7/41.8 ppm K−1, and storage modulus of 3.7/3.8 GPa, respectively. The enhanced comprehensive performances make the all-carbocycle hydrocarbon resins good candidates for next-generation interlayer dielectrics.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Pengbo Li,Yuanrong Zhang,Haodi Liu,Yanfen Fang,Shuaitao Li,Xun Hu,Qifeng Chen
The conjugated structure of graphitic polymeric carbon nitrides (GPCNs) has low efficiency in the photocatalytic hydrogen peroxide (H 2 O 2 ) production, due to the electronic properties, band structure, and surface-active-sites. Herein, boron and carbon-ring modified GPCNs were synthesized with via a thermal condensation method, using melamine and phenylboronic acid as raw materials. The introduced boron atom, conjugated to the carbon atom in the heptazine moiety, and the adjacent nitrogen vacancy (V N ) formed a dual-site, which not only modified the electronic properties but also promoted the adsorption and activation of molecular dioxygen; The carbon-ring introduced altered the band structure and electron distribution, which was proved by density functional theory (DFT) calculations. The co-modification promoted the conversion of dioxygen molecule to H 2 O 2 , coupled with oxidation of benzyl alcohol (BA) to benzaldehyde (BAD). The optimal activity was achieved over CN-B 3 (1.87 mmol/(g·h)), which was about 4-fold higher than that of PCN (0.49 mmol/(g·h)). More interestingly, mechanism study revealed that the photocatalytic H 2 O 2 generation was realized via a photon energy transfer route, that is, O 2 molecule firstly was converted to a highly active singlet oxygen ( 1 O 2 ) intermediate, which was reduced by electrons to superoxide anions ( O 2 − ) and coupled with proton to form H 2 O 2 . This method provides a novel strategy to improve photocatalytic H 2 O 2 and high value-added chemical production by regulating the microstructure and electronic structure of GPCNs through heteroatom and moiety co-modification.
研究领域:
材料科学
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环境科学
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Lingli Wang,Yu Zhu,Dan Yang,Lei Zhao,Hanming Ding,Zhaohui Wang
Effective photogenerated charge separation and rapid Cu(II)/Cu(I) redox cycling is still challenging for photocatalytic reactions and copper-based Fenton-like process, respectively. Herein, a novel heterogeneous Fenton-like catalyst of copper incorporated carbon ring- g -C 3 N 4 (Cu-C-CN) was prepared through a facile calcination method. The carbon ring could be intimately connected with g -C 3 N 4 via sp 2 -hybridized C N bonds to form an in-plane π-conjugated structure. The carbon ring spliced g -C 3 N 4 (C-CN) can serve as an effective electron-hole separator owing to the varied electron affinity of two domains (e.g. carbon-ring and g -C 3 N 4 ). The copper species were further introduced to the framework of g -C 3 N 4 via the Cu N bonds to act as acceptors of conduction-electrons from g -C 3 N 4 and H 2 O 2 activators. Taking the photodegradation of methylene blue (MB) as a model reaction, the decomposition efficiency over Cu-C-CN is 5.5 times higher than that of pristine g -C 3 N 4 , and would nearly linearly increase with pH. The notable enhancement in photodegradation efficiency could be ascribed to the synergetic collaboration between photocatalysis process and Fenton-like process to generate abundant OH and e − . The Cu-C-CN catalyst shows high recycling stability with negligible Cu leaching due to the strong affinity of Cu 2+ to g -C 3 N 4 framework. The strategy of coupling Fenton-like catalysts, electron-deficient domains (e.g. carbon-ring) into semiconductor-based photocatalysis provides a facile and promising solution to the remediation of water pollution with solar energy.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 11
·3420-3430
·
IF 4
Hongxiao Lv,Liming Fan,Tuoping Hu,Chenxu Jiao,Xiutang Zhang
The efficient catalytic performance displayed by MOFs is decided by an appropriate charge/radius ratio of defect metal sites, large enough solvent-accessible channels and Lewis base sites capable of polarizing substrate molecules. Herein, the solvothermal self-assembly led to a highly robust nanochannel-based framework of {[In4(CPDD)2(μ3-OH)2(DMF)(H2O)2]·2DMF·5H2O}n (NUC-66) with a 56.8% void volume, which is a combination of a tetranuclear cluster [In4(μ3-OH)2(COO)10(DMF)(H2O)2] (abbreviated as {In4}) and a conjugated tetracyclic pentacarboxylic acid ligand of 4,4′-(4-(4-carboxyphenyl)pyridine-2,6-diyl)diisophthalic acid (H5CPDD). To the best of our knowledge, NUC-66 is a rarely reported {In4}-based 3D framework with embedded hierarchical triangular-microporous (2.9 Å) and hexagonal-nanoporous (12.0 Å) channels, which are shaped by six rows of {In4} clusters. After solvent exchange and vacuum drying, the surface of nanochannels in desolvated NUC-66a is modified by unsaturated In3+ ions, Npyridine atoms and μ3-OH groups, all of which display polarization ability towards polar molecules due to their Lewis acidity or basicity. The catalytic experiments performed showed that NUC-66a had high catalytic activity in the cycloaddition reactions of epoxides with CO2 under mild conditions, which should be ascribed to its structural advantages including nanoscale channels, rich bifunctional active sites, large surface areas and chemical stability. Moreover, NUC-66a, as a heterogeneous catalyst, could greatly accelerate the Knoevenagel condensation reactions of aldehydes and malononitrile. Hence, this work confirms that the development of rigid nanoporous cluster-based MOFs built on metal ions with a high charge and large radius ratio will be more likely to realize practical applications, such as catalysis, adsorption and separation of gas, etc.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xin Wang,Li Yang,Yanglin Chen,Chaokun Yang,Jianwen Lan,Jianmin Sun
The silicon-based materials with enriched superficial Si–OH groups are candidates in the field of the cycloaddition of CO2 to epoxide to cyclic carbonate; meanwhile, the triazine ring with a nitrogen-rich structure has shown a high adsorption affinity toward CO2 to polarize CO2. On this basis, a metal-free triazine-incorporated organosilica framework (SiTIOF) containing triazine rings, −NH, and Si–OH was prepared by substitution reaction and then a hydrothermal method. The prepared SiTIOF exhibited an outstanding catalytic activity for the cycloaddition of CO2 to epoxide with the cocatalyst tetrabutylammonium bromide (Bu4NBr) due to the triazine unit and multiple hydrogen bond donors (−NH, −OH). Besides, the SiTIOF catalyst could be reused six times and has good versatility to various epoxides with CO2 cycloaddition. Moreover, the possible reaction mechanism with a hydrogen bond donor (HBD) and halide anion synergistic catalysis was proposed.
研究领域:
材料科学
·
催化化学
·
环境化学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2024
·
IF 4.1
Ji Xiong,Ming-Hui Chen,Xiang-Yu Li,Quan Shi,Yun-Hao Xu,Ya-Qing Feng,Bao Zhang
The sunlight-driven CO 2 fixation into high value-added industrial products constitutes a promising approach to mitigating global warming, offering an alternative to traditional thermally-driven fixation requiring high temperature and/or high pressure. Herein, we design and synthesize four isostructural porphyrinic covalent triazine frameworks ( Por-CTFs ) including metal-free Por-CTF ( H2Por-CTF ) and metallized Por-CTFs ( MPor-CTFs , M = Co, Zn, Cu) and their photocatalytic activity in CO 2 cycloaddition. All Por-CTFs exhibit wide light adsorption range in visible region via introducing porphyrins into the covalent triazine frameworks (CTFs) skeleton. Different metal ions which are well anchored in the MPor-CTFs skeleton not only offer Lewis acidic sites for substrate interaction but also apparently endow photocatalysts with longer photogenerated carrier lifetimes and higher electron-hole separation efficiency. Encouragingly, under visible light-assisted and mild conditions, the CoPor-CTF exhibits excellent photocatalytic performance achieving a reaction rate of 62.22 mmol g −1 h −1 , which is among the state-of-the-art cases for photocatalytic CO 2 cycloaddition and outperforms two other MPor-CTFs . This work demonstrates that the photophysical and electronic properties of Por-CTFs can be rationally tuned by incorporating various metal ions into porphyrin units to achieve effective photocatalysts for CO 2 cycloaddition.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）