Small
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2024
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IF 13
Jinqiao Li,Lizheng Chen,Xuefeng Chu,Kaikai Ba,Tengfeng Xie,Wenfu Yan,Gang Liu
2D carbon nitride nanosheets, exemplified by g-C 3 N 4 , offers significant structural benefits and enhanced photocatalytic activity. Nonetheless, the quantum confinement effect prevalent in nanoscale photocatalysts would result in an enlarged bandgap, potentially restricting the spectral absorption range and impeding improvements in photocatalytic efficiency. Here, a high-performance 2D photocatalyst with an extended spectral response is achieved by incorporating a novel phenol-like structure into the conjugated framework of ultrathin g-C 3 N 4 nanosheet. This novel strategy features targeted pyrimidine doping to create a conjugated carbon zone in heptazine structure, offering a thermodynamically favorable pathway for hydroxyl functionalization during the annealing exfoliation process. Consequently, the π–π* transition energy in the material is significantly decreased, and the active lone pair electrons in phenol-like structure induces a new n–π* transition with notably enhanced absorption from 500 to 650 nm. The optimized material shows a dramatic enhancement in photocatalytic activity, achieving ≈72 times than the activity of bulk g-C 3 N 4 , and demonstrating a measurable H 2 production rate of 6.57 µmol g −1 h −1 under 650 nm light. This study represents a significant step forward in the strategic design of 2D photocatalysts, with tailored electronic structures that significantly boost light absorption and photocatalytic efficiency.
研究领域:
材料科学
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光化学
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DOI
PubMed
高影响因子
Catalysts
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2022
·Vol. 12
·期 12
·1496
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IF 4.501
Fengyun Su,Zhishuai Wang,Haiquan Xie,Yezhen Zhang,Chenghua Ding,Liqun Ye
Hydrogen evolution by photocatalytic technology has been one of the most promising and attractive solutions, and can harvest and convert the abundant solar energy into green, renewable hydrogen energy. As a new kind of photocatalytic material, graphitic carbon nitride (g-C3N4) has drawn much attention in photocataluytic H2production due to its visible light response, ease of preparation and good stability. For a higher photocatalyic performance, N defects were introduced in to the traditional g-C3N4in this work. The existence of N defects was proved by adequate material characterization. Significantly, a new absorption region at around 500 nm of N-deficient g-C3N4appeared, revealing the exciting n-π* transition of lone pair electrons. The photocatalytic H2production performance of N-deficient g-C3N4was increased by 5.8 times. The enhanced photocatalytic performance of N-deficient g-C3N4was attributed to the enhanced visible light absorption, as well as the promoted separation of photo-generated carries and increased specific surface area.Keywords:N defects;g-C3N4;H2evolution;photocatalysis;n-π* transition
研究领域:
材料科学
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能源科学
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Yan Ke,Mingzhu Yuan,Xinglong Li,Yuan Liu,Yangyang Li,Yuanxu Liu,Xiangang Lin,Qinghua Liu,Yupeng Yuan
Improving electron delocalization and optical absorption properties of graphitic carbon nitride (g-C 3 N 4 ) is essential for enhancing the performance of photocatalytic wastewater treatment. Herein, an enhanced electron delocalization with activation n-π∗ electronic transitions of g-C 3 N 4 (TCN m ) by embedding electron-rich pyrimidine units into the g-C 3 N 4 skeleton was successfully fabricated. Experimental characterizations and density functional theory calculations demonstrated that the precise incorporation of pyrimidine units into the g-C 3 N 4 skeleton reduces the degree of overlap of positive and negative charge centers, enhances the delocalization of conjugate electrons, and facilitates carrier separation. Furthermore, this novel structure introduced additional n-π∗ electronic transitions, extending the light-absorbing edge beyond 700 nm. As a result, after 60 min of light irradiation, TCN m exhibited the highest kinetic constant (0.0287 min −1 ) in the degradation of tetracycline, which was ∼3.8 times higher than that of pristine g-C 3 N 4 . In particular, the optimal antibacterial rate for Staphylococcus aureus reached 88.3% after 4 h of light exposure. These findings illustrate the remarkable potential of TCN m in addressing antibiotic and microbial contamination in water.
研究领域:
环境科学
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材料科学
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化学
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2025
·
IF 2.5
Miao Wang,Feixiang Ding,Yuren Zhao,Ge Xu
Conventional graphitic carbon nitride (g-C3N4) suffers from rapid complexation of photogenerated charge carriers and limited visible-light absorption. To address these issues, this study aims to construct an intramolecular donor–acceptor system within g-C3N4 to precisely modulate its electronic structure and enhance photocatalytic performance. A novel carbon nitride-based composite photocatalyst (CN-abIM9mg) was synthesized via a two-step thermal condensation method using 2-aminobenzimidazole (abIM) as a dopant. The ultratrace doped donor provides an electron transfer mode requiring lower energy, which narrows the band gap of g-C3N4 from 2.79 eV to 2.70 eV and expands the absorption capability to visible light. Furthermore, CN-abIM9mg has a specific surface area of 112.215 m2 g−1, which is 3.5 times higher than that of g-C3N4 (32.156 m2 g−1), supplying more photocatalytic active sites. A possible mechanism was proposed based on characterization using X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, and density functional theory simulation calculations. In addition to the π–π* transition originating from the pristine g-C3N4, the occurrence of n–π* electronic transition within the donor–acceptor system enhanced the delocalization ability of the photogenerated charge carriers. The synergistic effects of improved light absorption, efficient charge separation, and increased surface area endow CN-abIM9mg with high photocatalytic activity, leading to a 98.8% degradation rate for Rhodamine B under visible light, with a reaction rate constant 4.9 times that of pure g-C3N4. This work provides profound molecular-level insights into enhancing photocatalytic activity through n–π* transition promotion in donor–acceptor-structured polymers.
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高影响因子
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