JOURNAL OF CATALYSIS
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2024
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IF 6.5
Mingyuan Guo,Yongning Ma,Zhanqing Liu,Donghua Wang,Yuhao Yang,Xiaolong Li,Enzhou Liu
Halogen doping is an effective approach to regulate the electronic structure and improve photocatalytic properties of g-C 3 N 4 . Here, a salt-assisted approach was employed to prepare layered porous halogen-doped g-C 3 N 4 . The effects of halogen electronegativity and pore morphology were discussed. Highly electronegative F-doped g-C 3 N 4 with smaller pore size and higher surface area displayed the enhanced absorption property on reactants. The H 2 production rate decreased and the RhB degradation significantly increased with increasing the electronegativity of layered porous g-C 3 N 4 , which was significantly different from the conventional halogen-doped g-C 3 N 4 prepared with halogenated acid and monolayer g-C 3 N 4 . The decreased H 2 evolution can be ascribed to the strong adsorption property, and the strong interactions between halide ions and H + were difficult to be disassociated. Additionally, the RhB degradation performance of halogen-doped g-C 3 N 4 significantly increased with increasing the electronegativity. The most active species that dominated the RhB degradation of F-doped g-C 3 N 4 are leaved holes (h + ), which are totally different from that of the pristine g-C 3 N 4 and Cl/Br-doped g-C 3 N 4 (superoxide radicals,·O 2 – ). This work helps us to well understand the role and importance of electronegativity and pore morphology on the H 2 generation and RhB degradation properties of layered porous g-C 3 N 4 .
研究领域:
材料科学
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环境科学
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DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2025
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IF 9.8
Mingyang Zhang,Likun Zang,Hui Tong,Fuyuan Liu
Polyetherimide (PEI), as a kind of high-temperature dielectrics, still face the issue of current leakage under thermo-electrical coupling fields, leading to a sharp degradation of energy storage performance. In this study, an intrinsic PEI with superior comprehensive properties was synthesized using 4,4'-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) and 2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP) . Through molecular design, an "electron gate" mechanism was introduced via σ-π hyperconjugation effects , effectively suppressing long-range charge delocalization. The resulting intrinsic PEI achieves an energy storage density ( U d ) of 1.93 J/cm 3 at 150 °C , which is 20.6 % higher than that of commercial Ultem™ PEI film (1.6 J/cm 3 ). Further modification was conducted by doping with three molecular semiconductors: 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). Density Functional Theory (DFT) simulations and Low-Energy Inverse Photoemission Spectroscopy (LEIPS) experiments reveal that all three semiconductors exhibit higher electron affinity than the intrinsic PEI. Additionally, Thermally Stimulated Depolarization Current (TSDC) reveals that the incorporation of molecular semiconductors increases trapped charges and trap energy level compared to intrinsic PEI. Both experimental and simulation results consistently demonstrate that molecular semiconductor doping can enhance energy storage performance by constructing deep trap sites within the PEI matrix. Experimental results demonstrate that at 150 °C, the 0.125 % PTCDI-doped PEI achieves a breakdown strength of 545 MV/m, an U d of 3.71 J/cm 3 , and a charge-discharge efficiency ( η ) of 90.13 % (vs. 436 MV/m, 1.93 J/cm 3 , and 94.67 % for intrinsic PEI). This research provides an effective strategy for improving the capacitive performance of polymer dielectrics under thermo-electrical coupling conditions.
研究领域:
高分子材料科学
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介电物理
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能源材料
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功能高分子
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热电耦合效应
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2025
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IF 8.2
Longkui Zheng,Yang Xiang,Dawei Zheng,Ning Luo
In this study, we systematically investigate the triboelectric performance degradation of polytetrafluoroethylene (PTFE)-based triboelectric nanogenerators (TENGs) under high–low temperature cycling and humidity variations, a critical yet underexplored challenge in extreme environmental applications. Under accelerated aging conditions spanning 0–300 thermal cycles and 0–90% RH, PTFE films demonstrated progressively worsening electrical output, their short-circuit current declining steadily from 7.2 to 4.6 μA, alongside an open-circuit voltage drop from 400 to 240 V. Surface characterization via scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy reveals that thermal cycling induces microstructural defects and chemical oxidation, where oxygen content replaced C–F bonds with weaker electron-accepting groups (C–O, C═O). This oxidative degradation reduced PTFE’s electron affinity and directly impaired charge transfer efficiency in TENGs. To address performance unpredictability, an improved extreme learning machine algorithm is developed, achieving 100% accuracy in real-time classification of PTFE aging states by analyzing triboelectric signals. Furthermore, paired with pristine PTFE, aged PTFE modified surface states enable a 21.8-fold power output enhancement and outperform conventional configurations. These findings establish a mechanistic framework linking thermal-humidity aging to triboelectric decay while proposing machine-learning-driven predictive maintenance strategies for TENGs in aerospace, energy systems, and autonomous devices operating in harsh environments.
研究领域:
材料科学
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纳米技术
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电气工程
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表面科学
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机器学习
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环境测试
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高分子科学
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产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2025
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IF 19
Bihong Chen,Yuehua Pan,Yuxiang Deng,Yunhao Hou,Haixuan Liang,Nannan Wang,Jun Luo,Kai Chen,Xinpeng Wang
Pyridine heterocyclic covalent organic frameworks (COFs) have attracted widespread attention in the field of photo-driven hydrogen peroxide (H 2 O 2 ) synthesis due to their unique optoelectronic properties and excellent electron affinity. In this study, the microenvironment change of COFs is achieved through the system regulation of pyridine content in its skeleton. Among these COFs, the bipyridine-structured TpDaBp exhibits the best visible-light-driven H 2 O 2 evolution rate of 8156 µmol g −1 h −1 and reveals significant potential for photocatalytic uranium extraction, attributed to its enhanced π–π interactions, improved optoelectronic performance, and enlarged specific surface area. This work not only provided a new strategy for further designing novel pyridine N-heterocyclic-based COFs but also shows its novel advantages of application.
研究领域:
材料科学
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光催化
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有机化学
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能源化学
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环境修复
✓ 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）