Nanomaterials
·
2025
·Vol. 15
·期 5
·365
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IF 4.3
Yijie Shen,Zhe Liu,Renke Bi,Bianbian Zhou,Yan Wang,Jialong Liu,Zhiyu Wang,Bing Han
Photodegradation of antibiotics based on photocatalytic semiconductors is a promising option to alleviate water pollution. Despite its limitations, TiO2-based photocatalysts are still the most widely studied materials for pollutant degradation. In this work, a pomegranate-like g-C3N4/C/TiO2nano-heterojunction was constructed using the hydrothermal–calcination method, consisting of interconnected small crystals with a dense structure and closely contacted interface. Low-crystallized carbon filled the gap between TiO2and g-C3N4, forming a large interface. The local in-plane heterostructures generated by C/g-C3N4are further improved for carrier transport. As expected, the optimal sample calcined at 300 °C (GTC-300) efficiently eliminated tetracycline hydrochloride (TC-HCl, 20 mg L−1), achieving a removal rate of up to 92.9% within 40 min under full-spectrum irradiation and 87.8% within 60 min under the visible spectrum (λ > 400 nm). The electron mediator, low-crystallized carbon, successfully promoted the formation of new internal electric fields via the widespread heterojunction interface, which accelerated the separation and migration of photogenerated carriers between g-C3N4and TiO2. These results confirm that the g-C3N4/C/TiO2nano-heterojunction exhibited outstanding photodegradation performance of TC-HCl. The electron mediator shows great potential in promoting carrier transfer and enhancing photocatalytic performance of heterogeneous photocatalysts in water treatment.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CARBON
·
2023
·
IF 10.9
Bin Wang,Yaotian Yan,Jinghuang Lin,Yifei Cai,Jian Cao,Junlei Qi
Efficient multi-path heat dissipation is urged to be designed for balancing the heat density generated in highly integrated electronic devices. Herein, aluminum foam/carbon composites were fabricated by chemical bath and annealing method to realize the effect of strengthening the effective thermal conductivity while retaining the convective heat transfer characteristics of the porous structure . The results show that the continuous and high crystalline carbon coating can be obtained in the optimized composites prepared with 350 g dopamine addition at 600 °C annealing temperature. When compared with amorphous carbon , the phonons in crystalline carbon can carry more energy during the heat transport in terms of high phonons density of states, and their scattering behavior can be alleviated. A smaller temperature gradient is further established in the system. Hence, a desirable thermal conductivity, 21.44 W m −1 K −1 , is obtained in the optimized composites, which is almost 3 times that of pristine aluminum foam (7.67 W m −1 K −1 ). Additionally, the remarkable cooling efficiency of 24.71% in comparison to other studies, suggests that aluminum foam/carbon composites hold great potential as thermal management materials in addressing the issue of intense heat generation.
研究领域:
材料科学
·
热管理工程
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DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 2
·312
·
IF 2.7
Zijie Xiao,Yayun Wang,Hui Chen,Haotian Wang,Yuke Li,Yilin Chen,Yun Zheng
Black phosphorus (BP) and heptazine-based crystalline carbon nitride (KPHI) composite photocatalysts were synthesized by molten salt and ultrasound-assisted liquid phase exfoliation methods. The structure, morphology and optical properties of the as-prepared BP/KPHI composites were evaluated by various characterization techniques. In addition, the photocatalytic performance of BP/KPHI composites for hydrogen production was investigated. The photocatalytic activity of BP/KPHI composite catalysts could be modulated by changing the loading mass ratio of BP. The BP/KPHI composite photocatalyst with a mass ratio of 10% exhibited the highest photocatalytic activity with the hydrogen production rate of 4.3 mmol g−1h−1, about three times higher than that of pristine KPHI. Benefiting from the advantages of simplicity, rapidity, high yield and good controllability, this nanocomposite photocatalyst has the potential to serve as an excellent photocatalytic material for solar energy conversion.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
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IF 9.7
Yueyang Tan,Yayun Pu,Zhongyan Zhang,Yabin Jiang,Lei Zeng,Chao Cai,Lu Jia,Weiman Zhuang,Zongzhao Sun,Limin Huang
In the typical ionothermal synthesis of crystalline carbon nitride (CCN), alkali metal halides are usually used in large amounts. Here, we report a new method for synthesizing poly (heptazine imide) (PHI) using only a trace amount of NaF, which is 20 times less than the amount of NaCl typically required to achieve the PHI structure. Different from the prevailing view that salts function primarily as templates and chelating agents during polymerization, our research revealed the unique role that NaF plays in the polymerization of PHI. We propose a new formation mechanism, termed the “pinning-docking mechanism,” in which fluoride (F) atoms and bidentate nitrogen atoms (N) coordinated to sodium (Na) atoms build a strong triangle configuration that synergistically promotes the formation of PHI. Calculations indicate that the highly electronegative F atom generates an effective electron flow within the N-metal-F complex, causing local electron reorganization and accordingly activating the N sites for H 2 evolution. The synergistic roles of Na and F atoms in NaF for synthesizing PHI cannot be replicated with either NaCl or NH 4 F salts under low dosage conditions. The synthesized PHI structure exhibits an exceptional hydrogen evolution rate of 10.2 mmol h −1 g cat −1 , exceeding that of amorphous TCN (550) by 217 times. This work provides an economical method for CCN synthesis and explores the underlying role of NaF salt during polymerization, which can be valuable for designing highly crystalline carbon nitride materials.
研究领域:
材料科学
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化学工程
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能源科学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yingfei Wang,Junhui Zhou,Fengliang Wang,Yi Xie,Shengwei Liu,Zhimin Ao,Chuanhao Li
Degrading organic pollutants while generating hydrogen from water splitting is an ideal application of photocatalysis. Herein, we presented an efficient photocatalyst, oxygen-doped crystalline carbon nitride, to power the degradation of various kinds of pharmaceuticals and personal care products and the simultaneous hydrogen production. The highest efficiency was achieved in treating the simulated wastewater containing naproxen (NPX), with the H 2 evolution rate of 819.1 µmol/g/h and the NPX degradation efficiency of 92 % upon visible light irradiation. Experimental and computational results suggested that the doped oxygen atoms thermodynamically favored the generation of hydroxyl peroxide for pollutant degradation and lowered the energy barrier of H 2 O reduction to produce hydrogen fuel. Most importantly, the catalysts functioned well in the natural aquatic environment including sea water, sewage water, river water, and well water. This study provides fundamental insights into photocatalytic water treatment with simultaneous hydrogen production, indicating an energy-recovering approach for wastewater treatment.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2022
·Vol. 19
·期 23
·15707
·
IF 4.614
Meirou Huang,Huiqin Guo,Zhenxing Zeng,Hong Xiao,Hong Hu,Liu He,Kexin Li,Xiaoming Liu,Liushui Yan
The photocatalytic conversion of lignin to aromatic compounds in aqueous solutions is a promising approach. We herein report a crystalline carbon nitride prepared by high-temperature thermal polymerization and alkali-metal molten salt treatment, which was then applied in the selective conversion of lignin to aromatic compounds. The results showed that the tri-s-tri-C3N4presented a relatively high activity and selectivity for the conversion of lignin in aqueous solutions. In a 95% water–acetonitrile solution, it achieved a relatively high conversation rate of lignin, reaching 62.00%, and the selectivity of the C-C bond cleavage was high, at 86.8%. The characterization results obtained by TEM, UV-vis/DRS, PL, and transient photocurrent response showed that the ultra-high activity of tri-s-tri-C3N4was mainly due to the improvements in crystallinity and light absorption. Mechanism studies showed that the dispersion of the catalyst and the combination of lignin and catalyst in aqueous solvents with different acetonitrile ratios were the main factors affecting lignin conversion. As the water content in the solutions increased, the primary active sites were converted from h+to ·O2−. This study revealed the interactions between lignin, photocatalysts, and reaction solutions, providing a theoretical basis for the photocatalytic conversion of lignin in aqueous solutions.Keywords:crystalline carbon nitride;photocatalysis;lignin;aqueous solution effect;aromatic compounds
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2023
·Vol. 49
·期 5
·1801-1817
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IF 3.3
Wu Zhiwen,Wang Bo,Zhu Yean,Xue Jinming,Nie Yidan,Xie Zongbo,Le Zhanggao
It is critical to recover uranium from wastewater containing U(VI) and to ensure the commercial development of nuclear-related energy sources. The extraction and recovery methods of uranyl ions from contaminated areas have become clearer with the rapid development of photocatalytic technology. However, there are several challenges, such as low-charge carrier migration and a lack of active sites. Crystallized carbon nitride (CCN) catalysts at different temperatures were successfully obtained to improve the efficiency of photocatalytic reduction of uranium. The characterization results show that the crystallinity of the material increased and improved the electron–hole separation efficiency. We investigated the effects of catalyst dosage, pH value of a solution, and concentration of U(VI) on the photocatalytic reactions as well as the photoreduction mechanisms. The efficiency of photocatalytic reduction of uranium is enhanced by 2.5 times with good stability in five cycles compared with bulk carbon nitride. The results demonstrate that CCN can effectively remove U(VI) by photocatalytic reduction, which has a wide range of applications prospects in the treatment of uranium-containing wastewater.
研究领域:
材料科学
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环境科学
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核能技术
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DOI
高影响因子
ChemSusChem
·
2021
·Vol. 14
·期 20
·4516-4524
·
IF 8.928
Guoqiang Zhang,Yangsen Xu,Hongwei Mi,Peixin Zhang,Haowen Li,Yujuan Lu
Graphical Mind the gap : A series of heptazine-based K + -implanted crystalline carbon nitride (CCN) materials with narrow bandgap (2.87–1.86 eV) are constructed by copolymerization of pyrimidine donor, which exhibits a superior photoactive wavelength to CCN-based photocatalysts. This work offers a universal donor bandgap strategy without sacrificing the reduction ability of photogenerated electrons towards photocatalytic reduction reactions. Crystalline carbon nitride (CCN) with a light response up to 700 nm has been seldom reported but is significant for the artificial photocatalysis. In this study, it is proposed that, unlike acceptors, introducing donors can effectively narrow the bandgap without sacrificing the reduction ability of photogenerated electrons, which is more advantageous to photocatalytic reduction reactions. Hence, a series of heptazine-based K + -implanted CCN (KCN) with a narrow bandgap (2.87–1.86 eV) are constructed by copolymerization of pyrimidine donors. The optimized photocatalysts can extend the light response to 700 nm and account for approximately 122- and 33-fold enhancements in H 2 production ( λ >500 nm) in comparison to CN and KCN, respectively. The apparent quantum efficiency (AQE) can reach 8.2 % at 500 nm and is comparable to the top-level CN- and CCN- based materials. Its photoactive wavelength has significant advantages over previously reported CCN-based photocatalysts. This method offers a universal donor bandgap engineering strategy towards photocatalytic reduction reactions.
研究领域:
材料科学
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光催化
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Zhihan Yu,Chen Guan,Xiaoyang Yue,Quanjun Xiang
Enhancing the carrier separation in graphitized carbon nitride (g-C 3 N 4 ) is advantageous for improving its photocatalytic activity. Herein, we propose a feasible method for preparing CN-C by thermal polymerization to gradually infiltrate carbon rings (C-rings) into the surface of crystalline carbon nitride (CN), enabling photogenerated electrons to be transferred rapidly between the CN inner layers and the CN/C outer layer. Successful penetration and distribution of carbon rings into carbon nitride were confirmed by secondary ion mass spectroscopy using ratio analysis of C and N elements at various depths of the prepared photocatalyst. Theoretical calculations indicated that CN and CN/C in the molecule generated different Fermi levels to form an S-scheme homojunction, establishing appropriate built-in electric fields and thus enabling interlayer charge migration. Moreover, the overlap of the conjugate plane of C-rings with carbon nitride led to the formation of photogenerated in-plane charge transfer tunnels. The two-electron transfer tunnels greatly improved the dissociation efficiency of photogenerated electrons. The prepared sample loaded with 3 wt% Pt as a co-catalyst for hydrogen production under visible light irradiation, and the prepared optimal sample CN-C showed a maximum quantum efficiency of 15.56% for photocatalytic H 2 evolution at 385 nm. This research introduces a new idea for constructing a directional transfer path for charge carriers in-plane and intralayer.
研究领域:
材料科学
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光催化
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产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 20
·205707
·
IF 3.874
Chongyang Zhang,Zhi Liu,Pan Xu,Ying Zhang,Xigui Yue
With the rapid development of electronic devices and wireless communication tools, it is urgent to design and fabricate low-cost, lightweight and effective electromagnetic absorption materials to solve interference of electromagnetic waves. Herein, a new strategy toward porous carbon/graphite nanosheet/ferromagnetic nanoparticle (PC/GNS/Fe) composites was designed to investigate the influence of crystalline carbon on electromagnetic wave absorption. To begin with, graphite nanosheets (GNSs) were incorporated into the porous polyimide by in situ polymerization, and Fe were added as a magnetic particle source and an agent to regulate the pore size. A series of PC/GNS/Fe composite absorbents were obtained. The direct carbonization of porous polymer precursors was beneficial to the design of the pore structure of materials. A hierarchically porous structure derived from the phase separation process was well maintained in the polyimide pyrolysis process. The results demonstrated that the presence of crystalline carbon could influence the reflection loss value and the frequency range. Hence, the absorbing performance can be optimized by adjusting the pore structure and the content of crystalline carbon in materials, which is conducive to obtaining electromagnetic wave absorption materials with excellent comprehensive performance.
研究领域:
材料科学
·
电磁学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Tingting Huo,Quanhua Deng,Fei Yu,Guoan Wang,Yuguo Xia,Haiping Li,Wanguo Hou
Crystalline carbon nitride (CCN) with a poly(heptazine imide) structure is efficient in photocatalytic hydrogen evolution (PHE), but synthesis of CCN ultrathin nanosheets (CCNuns) and their use in PHE with selective organic oxidation are still rare. Herein, CCNuns with Na+ doping are prepared using NaCl as the ion-induction and templating agent and mesoporous melon as the feedstock, exhibiting efficient synchronous PHE and benzyl alcohol oxidation to benzaldehyde, with an apparent quantum yield of 10.5% at 420 nm and a visible light PHE rate that is 94.3 times that of bulk polymeric carbon nitride (PCN). The selectivity of benzaldehyde formation (90.5%) is also much higher than that of PCN (40.7%). Interestingly, this selectivity increases gradually with increasing light wavelengths. The high photoactivity of CCNuns originates from their ultrathinness and Na+ doping, which considerably enhance the photogenerated charge separation. This work opens up an avenue for the synthesis of CCNuns and extends their application.
研究领域:
材料科学
·
光催化化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wenjing Huang,Hongbo Ming,Xiaoqiong Bian,Can Yang,Yidong Hou,Kaining Ding,Jinshui Zhang
The activation of peroxymonosulfate (PMS) over carbon nitride-based photocatalysts towards refractory organic removal has received growing attention in wastewater treatment. In this study, we successfully synthesized copper single atoms incorporated into crystalline carbon nitride (Cu-CCN) and applied it to activate PMS towards bisphenol A (BPA) removal. The characterization and theoretical calculation results indicated that Cu-CCN had good crystallinity, outstanding charge separation and transfer ability, and numerous PMS adsorption and activation sites provided by Cu single atoms. Consequently, Cu-CCN demonstrated an enhanced ability to activate PMS for BPA degradation. The activity performance of Cu-CCN was affected by the experimental conditions at different levels, and the catalyst had good stability in structure and activity during cyclic runs. A plausible reaction mechanism was also proposed according to free radical trapping and quenching experiments. This oxidation process can efficiently degrade organic pollutants as well as reduce the toxicity. The findings of this work elucidated an efficient photocatalyst for activating PMS towards organic removal and might guide the design of other metal single-atom modified photocatalysts.
研究领域:
环境科学
·
材料科学
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化学工程
✓ 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）