Materials Today Chemistry
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2022
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IF 7.613
Tian Xia,Zhuangzhuang Wu,Ying Liang,Wenxin Wang,Yongpeng Li,Zhuyin Sui,Linlin Shan,Chaokun Li,Ruimei Fan,Qi Chen
The design and fabrication of versatile covalent organic frameworks (COFs) with multiple properties for diverse applications is highly desirable. Here, the difunctional COFs material g–C 18 N 3 –COF was prepared and modified to be applied for efficient photocatalytic degradation of Rhodamine B (RhB) and pH detection, respectively. Owing to the triazine unit which was suitable for photocatalyst construction, g–C 18 N 3 –COF was sensitive to visible light and exhibited excellent photocatalysis capability toward RhB. Specially, the photocatalytic degradation of RhB with a high concentration of 300 ppm using g–C 18 N 3 –COF reached equilibrium within 6 h. Moreover, g–C 18 N 3 –COF was further grown in-situ onto the filter paper to generate a novel composite material g–C 18 N 3 –COF@Paper with bright yellow fluorescence. g–C 18 N 3 –COF@Paper could visualize the pH detection by remarkable changes in its fluorescent intensity and color in the range of pH value from 1 to 5, on account of the protonation of the nitrogen atoms from the triazine ring in g–C 18 N 3 –COF. The triazine-based sp 2 carbon-conjugated g–C 18 N 3 –COF, respectively, used as photocatalyst and sensor in this work offers a new strategy to construct the versatile COFs material, facilitating the application of functional COFs in the environmental protection field.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
Catalysis Science & Technology
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2021
·Vol. 11
·期 16
·5663-5670
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IF 6.119
Mengqi Xue,Daochuan Jiang,Haiwei Du,Zhongjun Li,Hong Bi,Yupeng Yuan
Localizing charge carriers close to catalytically active sites can reduce the charge recombination in photoexcited polymeric carbon nitride (PCN), which thus potentially increases its photocatalytic H2 generation. However, this strategy has not been applied to enhance the photocatalytic performance of PCN. Herein density functional theory (DFT) calculations unravel that N defect (Ndefect) engineered tri-s-triazine units form a highly localized mid-gap state in PCN, which can localize the π electrons for efficient separation of electrons and holes. Moreover, Ndefect engineered tri-s-triazine units impart the lowest Gibbs free energy barrier of −0.129 eV for the reduction of H+ to adsorbed H, thereby serving as the catalytically active sites. Enlightened by theoretical results, the Ndefect engineered tri-s-triazine units were created via post oxidation of PCN in an electronic furnace. Such PCN with N defects offers an increased photocatalytic H2 generation under visible light exposure. The highest H2 generation rate is up to 98.1 μmol h−1, 3.8 times higher than that by using pristine PCN (26.1 μmol h−1). This work manifests the significance of localizing charge carriers close to the catalytically active sites for increased photocatalytic performance of PCN.
研究领域:
材料科学
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理论计算化学
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高影响因子
Journal of Materials Chemistry A
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2024
·Vol. 12
·期 38
·25761-25772
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IF 10.7
Zibin Li,Ya Chu,Fanpeng Meng,YunYun Dong,Jinsheng Zhao,Huayang Zhang,Xiujuan Zhong
Conjugated porous polymers (CPPs) incorporating donor–acceptor (D–A) structures are gaining significant interest for their potential in photocatalytic hydrogen evolution reaction (HER). The microstructure and electronic properties of the polymer frameworks are crucial for optimizing their photocatalytic efficiency. Here, we design two D–A type CPP photocatalysts using 4,8-di(thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene (DBD) and triazine units to investigate the impact of different bridging units on HER activity. Compared with PhDBD–CPP using benzene as the bridging unit, ThDBD–CPP with a thiophene linking unit achieves an expansion of the HOMO orbital distribution and an enlarged molecular dipole moment, which is conducive to the efficient separation and migration of photogenerated carriers. Consequently, ThDBD–CPP with thiophene as the bridging unit exhibits a remarkable photocatalytic hydrogen evolution rate of 20.75 mmol h−1 g−1 under full arc light. After loading 1 wt% Pt cocatalyst, the HER activity is further improved to 30.36 mmol h−1 g−1. This study suggests that modulating bridging units provides a new viable approach to designing efficient polymer photocatalysts.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Ming Li,Junying Ma,Bingli Pan,Junling Wang
A cage-covalent organic framework (COF)-TP {T = bis(tetraoxacalix[2]arene[2]triazine); P = piperazine}, a novel two-dimensional covalent organic skeleton substituted with a nucleophilic cyanuric chloride analogue, was synthesized by a simple polymerization process. Cage-COF-TP is advantageous owing to its good structural order, permanent porosity, and low preparation cost. This skeleton was employed as a cost-effective adsorbent for the intermittent adsorption of an organic dye from aqueous solutions. Adsorption experiments were carried out at different initial dye concentrations, contact times, and solution pH. The adsorption kinetics followed the pseudo-second order model, and the results of thermodynamic studies were consistent with the Langmuir isotherm model. The high degree of matching between the size and shape of malachite green (MG) and the shrunken channels present in Cage-COF-TP were responsible for the enhanced adsorption ability of this material. Furthermore, theoretical calculations indicated that the high adsorption of the studied adsorbent can be attributed to the presence of nitrogen-rich triazine units in the Cage-COF-TP, which are expected to strengthen its affinity to guest molecules. The obtained results showed that the developed adsorbent is an efficient adsorbent that is theoretically capable of stimulating the removal of ∼2000 mg/g MG from wastewater at ambient temperature. This study will therefore be expected to promote the development of new functional materials based on COFs.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
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2022
·Vol. 11
·期 2
·800-808
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IF 14.511
Yixuan Lv,Dandan Ma,Kunli Song,Siman Mao,Zhetong Liu,Dan He,Xuewen Zhao,Tianhao Yao,Jian-Wen Shi
The gradual depletion of global fossil energy and environmental pollution make the development of hydrogen energy an imminent concern. Two-dimensional g-C3N4 (CN) based heterostructures have attracted considerable research interest in the photocatalytic H2 evolution field, but the unsatisfactory interfacial contact between metal-free CN and other metal oxide/sulfide semiconductors usually results in a low transfer efficiency of charge carriers. Herein, we develop a new homojunction by in situ decoration of CN nanosheets with a C–N compound broken by s-triazine units (abbreviated to BST). The resultant CN/BST homojunction presents significantly enhanced photocatalytic H2 generation (12.47 mmol g−1 h−1), which is about 4 and 33 times higher than that of pristine CN (3.086 mmol g−1 h−1) and BST (0.376 mmol g−1 h−1), respectively. It is revealed that the BST fragments tightly anchored on the CN nanosheets act as electron-trapping agents to rapidly transfer photogenerated electrons from the CN conduction band to generate hydrogen, effectively inhibiting the recombination of photogenerated electrons and holes. The work shows that the construction of a suitable homojunction is an effective way to obtain high photocatalytic activity.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
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IF 16.683
Jingzhen Zhang,Chunyang Yu,Junyu Lang,Yongfeng Zhou,Baoxue Zhou,Yun Hang Hu,Mingce Long
Photocatalytic H 2 O 2 production (PHOP) on graphitic carbon nitride (GCN) at neutral pHs is limited by the sluggish oxidation of sacrificial alcohols and insufficient protons. In our work, the PHOP over a series of K intercalated triazine (KTCN) or tri-s-triazine units (KTTCN) reached 11–32 folds of GCN in the presence of only 0.5 vol% isopropanol, and a positive correlation between the H 2 O 2 production and the K contents was found. The critical role of K was revealed as that K intercalation creates Lewis acidic sites for isopropanol adsorption and strengthens Lewis basic sites for hydrogen abstraction and proton release. The improved alcohol oxidation and enhanced O 2 chemisorption synergistically result in dramatically accelerated PHOP over KTTCN. The findings provide the understanding of the preliminary active site dependent PHOP mechanism and bring insights for design of carbon nitride polymers with desirable photocatalytic performance.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yunchao Ma,Yuxin Yao,Shengnan Qi,Chuanxue You,Yuanyuan Wu,Chunbo Liu,Bo Hu,Keyu Cui
Herein, we successfully synthesized two photoactive donor–acceptor (D-A) covalent organic frameworks by incorporating electric-deficient triazine and electric-rich benzotrithiophene moieties into the framework. The introduction of sulfur atom and triazine unit significantly change the intrinsic band gap of JLNU-COFs, this leads to an expanded range of light absorption, encompassing wavelengths from ultraviolet to visible. The narrow band gap of JLNU-311 allows for efficient utilization of visible light while maintaining the thermodynamic activity required for nitrogen reduction within appropriate energy bands. JLNU-311 modified with strong electron absorbing groups has higher activity to NH 3 production without co-catalyst or sacrificial agent, and yield can reach 325.6 µmol/g/h. Theoretical calculation further confirm that acceptor structure can effectively regulate the band gap width, promote the adsorption, dissociation and protonation of N 2 molecules on JLNU-COFs, and thus reduce the energy barrier of photocatalytic nitrogen reduction reaction (PNRR). Therefore, this study provides an effective strategy for design of active nitrogen fixing photocatalysts.
研究领域:
材料科学
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催化化学
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环境科学
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高影响因子
DYES AND PIGMENTS
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2015
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IF 3.966
Yi Chen,Jingwei Xie,Zixing Wang,Jin Cao,Hongwei Chen,Jinhai Huang,Jianhua Zhang,Jianhua Su
Two novel indole-based, bipolar, host materials were designed and synthesized by introducing the triazine unit to the 5-position of indole moiety with a meta -linking strategy. The two host materials exhibited excellence bipolar transport abilities and the meta-linking analog presented a high T g value (>120 °C). Furthermore, their electrochemical and photo-physical properties were also fully characterized and all the results exhibited that the meta -linking strategy made a significant effect on the physical properties of the two hosts. Moreover, the PHOLED devices using 9-(4-(5-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)- 1H -indol-1-yl) phenyl)- 9H -carbazole and 9-(4-(5-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)- 1H -indol-1-yl)phenyl)- 9H -carbazole as hosts were also fabricated to evaluate the practical utilities of host materials. The devices achieved the maximum external quantum efficiencies of 17.53% for para -linking compound and 14.53% for meta -linking analog, respectively. In particular, para -linking compound based device revealed the maximum external quantum efficiency was twice that of the device using 4,4′-bis( N -carbazolyl)-1,10-biphenyl as the host.
研究领域:
有机电子学
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry A
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2017
·Vol. 5
·期 16
·7612-7617
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IF 8.867
Tongmou Geng,Zongming Zhu,Weiyong Zhang,Yu Wang
A new kind of nitrogen-rich fluorescent conjugated microporous polymer TTPB was synthesized via a Friedel–Crafts reaction of 2,4,6-trichloro-1,3,5-triazine (TCT) and N,N,N′,N′-tetraphenylbenzidine (TPB) catalyzed by methanesulfonic acid. Having structural features of an expanded conjugated area, N-rich, twisted structure, and microporosity in polymer networks, TTPB showed excellent, efficient, reversible ultrahigh absorption performance for iodine vapour with an uptake of up to 4.43 g g−1, which is the highest value reported to date for CMPs. Furthermore, fluorescence study indicated that TTPB exhibits high sensitivity to electron-deficient nitrobenzene explosives via fluorescence quenching.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）