Surfaces and Interfaces
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2023
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IF 6.2
Yijun Wang,Meijuan Ding,Ziyu Li,Mei Li
To facilitate the realize high-value utilization of coal tar pitch, carbon quantum dots (CQDs) were synthesized using ball-milling-assisted H₂O₂ oxidation method with tar pitch as carbon source. Subsequently, Ag₃PO₄/g-C₃N₄/CQDs composites were prepared through the electrostatic self-attraction of CQDs, Ag₃PO₄ and g-C₃N₄. These composites were then employed for the photocatalytic degradation of dyes, including methyl orange (MO), methylene blue (MB) and rhodamine B (RhB). A case study of MO, the degradation rate constant of Ag₃PO₄/g-C₃N₄/CQDs reached 0.02469 min −1 , which was 11 times and 1.6 times higher than that of g-C₃N₄ and Ag₃PO₄. It found that Ag₃PO₄:g-C₃N₄ mass ratio of 1:1 and 5 mg/L CQDs solution loading were optimal. Characterization analysis revealed the specific surface area of the catalyst was increased and optimized band gap structure after the combination of CQDs as the co-catalyst. The possible reaction mechanism was also expounded, Ag₃PO₄/g-C₃N₄/CQDs constructed Z-scheme heterostructure, with CQDs as electron bridge. In addition, the impact of catalyst mass, initial concentration, and pH on the degradation process was studied, as well as the cyclic stability of the catalyst. Based on capture and ESR tests, the main active substances involved in the reaction were in the following order: h + > ·OH > ·O 2 − . These experiments provided a new idea on the application of coal-based CQDs in the field of visible light catalytic degradation.
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ChemistrySelect
·
2023
·Vol. 8
·期 37
·e202302830
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IF 2.1
Hongyan Guo,Shu Wang,Lian Duan,Yue Sun,Shuwei Chen
Graphical A method for the synthesis of Nitrogen-Doped Carbon quantum Dots (N-CQDs) with 4-aminosalicylic acid and tartaric acid is proposed. The synthesized N-CQDs exhibit strong fluorescence and good photostability and can selectively detect CN − in solution. Selective and sensitive detection of Cyanide (CN − ) is critical essential due to it is one of the most lethal chemicals and threat to human health. In this study, nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by one-step hydrothermal method using 4-aminosalicylic acid and tartaric acid as raw materials. The prepared N-CQDs were spherical particles with good water solubility and uniform particle size distribution, the optimal excitation and emission wavelengths of N-CQDs were 495 nm and 514 nm, respectively. Based on the selective fluorescence quenching effect between CN − and N-CQDs, achieving accurate and rapid detection of CN − . Fluorescence quantum yield (PLQY) of N-CQDs is 39 %, and the other competing anions showed little or no interference to CN − . For highly sensitivity detections of N-CQDs under optimal conditions, the fluorescence quenching degree was linearly correlated with the CN − concentration in the range of 0–100 μM (R 2 =0.9929).
研究领域:
材料科学
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环境科学
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分析化学
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CATALYSIS LETTERS
·
2023
·
IF 2.8
Sun Wenwen,Guo Ruyue,Shi Chaojie,Li Xuechen,Wu Jiayi,Tian He,Li Huayi,He Jie,Yang Zhengchun,Li Jiahui,Sun Shanfeng
In this study, we prepared carbon quantum dots (CQDs)-modified 26-facet Cu/Cu 2 O composites and investigated their photocatalytic degradation effect on methyl orange (MO). The microstructure and composition of the reduction products were analyzed. The test results validate the successful modification of CQDs on the surface of Cu/Cu 2 O composites. Further, through electrochemical performance analysis among the materials with different thiourea dioxide (TD) contents, 3TD (n × 0.00075 mol of thiourea dioxide is defined as nTD) exhibits the strongest electron transfer ability; thus, 3TD was selected to further combine with CQDs to examine the photocatalytic performance of Cu/Cu 2 O composites. We analyzed the photocatalytic behavior of the composites by monitoring the degradation of the MO solution. Based on the photocatalytic performance test, the CQDs/3TD composite exhibits excellent photocatalytic activity. Following 120 min of visible light irradiation, the degradation rate of MO with the addition of loaded CQDs increased from 25 to 73%. Materials with both adsorption and photocatalytic properties were successfully prepared, which resolved the regeneration of adsorbents to a certain extent and further accelerated the degradation of dyes. Graphical Abstract
研究领域:
材料科学
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环境科学
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INORGANICA CHIMICA ACTA
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2021
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IF 2.545
Ji-Min Yang,Yun-Kai Kou
Metal-organic framework-based composites can help overcome the functional shortcomings of single materials by virtue of the synergetic properties of their components. The new functionalities introduced in the resulting material allow for their use in a wide range of applications. Herein, we prepared a fluorescent amino-CQDs@MIL-101-SO 3 H composite sensor by immobilizing amino-functionalized carbon quantum dots (amino-CQDs) on sulfo-modified MIL-101 nanoparticles. MIL-101-SO 3 H was not only used as a carrier to encapsulate the amino-CQDs in the pore cavity by hydrogen bonding interactions between the free -SO 3 H groups of MIL-101-SO 3 H and the –NH 2 group of the amino-CQDs, but also as an adsorbent to selectively adsorb and capture the target analyte, i.e. 2,4-dinitrophenol (DNP), via hydrogen bonding interactions between the free -SO 3 H groups of MIL-101-SO 3 H and the –NO 2 group of DNP. The amino-CQDs were used as a probe to sense the target molecules with high selectivity. The amino-CQDs@MIL-101-SO 3 H composite sensor displayed excellent selectivity and sensitivity toward DNP, with a detection limit of 0.041 μM. This is the first study to demonstrate the immobilization of fluorescent amino-CQDs in mesostructured MIL-101-SO 3 H. The selective fluorescence detection demonstrated herein will provide a new platform for sensing hazardous pollutants.
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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ACS Applied Materials & Interfaces
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2021
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IF 9.229
Chenghong Wu,Xiaopeng Chen,Liqun Tang,Qiaolu Wei,Xiaojie Wei,Jiezhen Liang,Linlin Wang
A key issue in attaining highly efficient supported catalysts for the hydrogenation of unsaturated polymers arises from the entanglement between the number of exposed active sites and the severe internal mass transfer limitation caused by their large molecular size. Hence, an ultrasmall N-doped carbon nanosphere with Ni NPs and CQDs embedded (Ni-CQDs/NCNs) was reasonably constructed by low-temperature (400 °C) pyrolysis of the precursor CQDs@Nano-Ni-ZIFs. As-prepared Ni-CQDs/NCNs exhibited superior catalytic activity to a commercial 10% Pd/C catalyst in petroleum resin hydrogenation under a low temperature of 150 °C, which is 100 and 60 °C lower than that of previously reported Ni- and Pd-based catalysts, respectively. The excellent catalytic activity of Ni-CQDs/NCNs mainly contributes to the following factors: first, its ultrasmall structure (ca. 50 nm) eliminates the internal mass transfer limitation; second, the CQDs and N-doped carbon matrix stabilize the 53.1 wt % high-loading Ni NPs at a small size of 5.6 nm, providing abundant active sites; and third, the electronic regulation of N-doped carbon enhances the intrinsic activity of Ni, which was revealed by the experiments and DFT calculations. Besides, Ni-CQDs/NCNs exhibits long-term stability and appreciable magnetic separation performance, making it a considerable candidate for industrial application. This work not only offers a facile approach to prepare nano MOF-derived catalysts but also gives helpful instruction to the rational design of heterogeneous catalysts for the reaction involving large molecules.
研究领域:
催化化学
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材料科学
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能源化学
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PubMed
高影响因子
WEAR
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2024
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IF 5.3
Xu Tan,Xiuqian Yu,Wenyang Huang,Yifan Zhou,Enzhu Hu,Xingkai Ding,Chuan Li,Kunhong Hu
Two kinds of the novelty lubricant additives (La/CQDs and MoS 2 -La/CQDs dispersions) were synthesized via a simply hydrothermal approach. The dispersions were demonstrated a significant enhancement in the lubrication performance of polyethylene glycol (PEG200). A series of modern analysis technologies were used to elucidate the anti-wear and anti-friction mechanisms of dispersions in PEG200. Results demonstrated that dispersions markedly improved the lubrication performance of PEG200 at 25, 75 and 100 °C. PEG200 containing 0.3 wt% MoS 2 -La/CQDs demonstrated the greatest decrease in the friction coefficient and wear rate, with reductions by 66.3 % and 35.5 % at 100 °C, respectively. Friction and wear mechanisms are ascribed to the engagement of nanoparticle-active components in both dispersions, which facilitate the formation of boundary lubrication films. 1
研究领域:
材料科学
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机械工程
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CERAMICS INTERNATIONAL
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2026
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IF 6
Cunxin Wei,Yiheng Cao,Haitao Li,Xinyue Jiang,Tianyi Zhang,Bin Zhang,Huiping Qi,Yan Liu
A CdS-WO 3 S-scheme heterojunction material modified by CQDs was constructed through simple methods, which effectively increases the photocatalytic degradation rate of single CdS. In the composite material, CdS acts as a reducing photocatalyst (RP) and WO 3 acts as an oxidizing photocatalyst (OP), forming an S-scheme heterojunction. In order to solve the photocorrosion problem of CdS, carbon quantum dots (CQDs) were loaded onto CdS. The CQDs possess a high work function, enabling them to facilitate electron transfer, enhance the migration of photogenerated carriers, and suppress electron-hole pair recombination, thus improving photocatalytic performance. The characterizations of XRD, TEM, element mapping, and XPS confirmed the successful synthesis of the CQDs-CdS-WO 3 composite. The material not only exhibited a photocatalytic degradation efficiency of 89.7% and 58.8% towards norfloxacin and tetracycline, respectively, but also revealed a certain degradation capability toward methylene blue and methyl orange. The primary active substances relevant in this degradation process are h + , 1 O 2 , H 2 O 2 , • O 2 − , and • OH. After multiple cyclic experiments, the material still maintains stable crystalline structure and degradation activity. Therefore, the successful preparation of this composite material provides a new method for photocatalytic decomposition of antibiotics and organic dyes.
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Analytical Methods
·
2023
·Vol. 15
·期 7
·944-950
·
IF 3.1
Wenzhan Yu,Qian Li,Liqiong He,Renlong Zhou,Lifu Liao,Jinhua Xue,Xilin Xiao
Camphor leaves were used as the precursor for the hydrothermal synthesis of carbon quantum dots. The preparation method is simple and rapid, and the raw material is environmentally friendly and easy to obtain. Without additional modification, the carbon quantum dots were used as fluorescent probes for the sensitive and selective detection of Fe3+ and isoniazid at different excitation wavelengths. For Fe3+, at the excitation wavelength of 320 nm, the ratio of fluorescence intensity of CQD solution after adding Fe3+ to CQD solution without Fe3+ addition, F/F0, and Fe3+ concentration showed a good linear relationship in the range of 2.72 × 10−5 to 1.00 × 10−4 mol L−1 (R2 = 0.9912), and the limit of detection was 8.16 μmol L−1. For isoniazid, at the excitation wavelength of 270 nm, the ratio of fluorescence intensity of CQDs solution with isoniazid to CQDs solution without isoniazid, F/F0, and isoniazid concentration showed good linear relationships in the range of 3.81 × 10−6 to 1.00 × 10−5 mol L−1 (R2 = 0.9941) and 1.00 × 10−5 to 2.10 × 10−4 mol L−1 (R2 = 0.9910) respectively, and the limit of detection was 1.14 μmol L−1. A fluorescence method for the determination of Fe and isoniazid content was proposed. The method has been used to detect iron in iron supplement tablets and isoniazid in isoniazid tablets with satisfactory results.
研究领域:
分析化学
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药物分析
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环境科学
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Jia Li,Wentao Liu,Yang Li,Zhi Liu,Yang Liu
A series of hierarchical flower-like CdS/carbon quantum dots/NiAl-LDH (CCL) photocatalyst have been successfully prepared to achieve efficient conversion of CO 2 -to-CO via a simple yet effective hydrothermal method. In the CCL, interspersed-CQDs not only increase the number of reactive sites but also reduce inner electronic impedance with the assistance of light reflecting-scattering effect. This significantly improves electron migration efficiency and inhibits the recombination of photoinduced electron-holes pairs. Without any sacrificial agent or photosensitizer, the sample of CCL-1 exhibits the highest CO evolution rate of 7.04 μmol·g −1 ·h −1 in water under simulated sunlight illumination with a large specific surface area (129.15 m 2 g −1 ) and an appropriate CQDs content of 15.2 wt%, which is 12.8- and 11.2-fold higher than those of pristine LDH, pure CdS, and many previously reported LDH-based counterparts. A type-Ⅱ interfacial charge transfer mechanism is proposed, where electrons migrate rapidly from CdS to LDH with highly-interspersed CQDs as unhindered electron conduction bridges. The present work outlines a simple and controllable LDH-based heterojunction, which give rise to superior photocatalytic activity for CO 2 photoreduction.
研究领域:
材料科学
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环境科学
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FUEL
·
2025
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IF 7.5
Hang Ye,Qi Liu,Tong Wu,Wanzhen Xue,Chunkai Wang,Kai Cheng,Tiong Michelle,Dan Luo,Chenggang Xian,Yiqun Liu
Asphaltene deposition is a significant issue in CO 2 -EOR, leading to reservoir damage and reduced efficiency. In this study, oil-soluble carbon quantum dots (CQDs) were synthesized to address asphaltene deposition issues, evaluating the inhibitory performance through laboratory experiments and molecular dynamics (MD) simulations. Experimental results demonstrated that CQDs effectively delayed the onset of asphaltene deposition from 45 vol% to 55 vol%, reduced the average particle size of asphaltene aggregates from 1200 nm to approximately 600 nm, and achieved an inhibition rate of 52.7 %. MD simulations revealed that CQDs reduced the mobility of asphaltene molecules and decreased the number of stacked asphaltene model molecules in aggregates from four to two, thereby lowering the risk of aggregation and subsequent deposition. Furthermore, the study showed that CQDs primarily inhibit asphaltene aggregation and deposition by weakening T-shaped or offset stacking interactions between asphaltene molecules. This effect was attributed to the strong interactions between CQDs and asphaltenes, with stabilization energies reaching up to −90 kcal/mol. Asphaltene molecules formed π-π interactions with CQDs through π-electron cloud overlap, dispersing the π-π interactions originally occurring between asphaltene molecules. This ultimately suppressed asphaltene aggregation. These characteristics suggested that CQDs offer a promising new approach to mitigate asphaltene deposition and have the potential to enhance oil recovery in low-permeability reservoirs.
研究领域:
石油工程
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材料科学
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计算化学
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2026
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IF 17.2
Qianqian Xu,Haihong Zhong,Chunli Li,Rong Jiang,Yongjun Feng,Luis Alberto Estudillo-Wong
Modulating the electronic structure of electrocatalysts represents a widely employed strategy to enhance the oxygen reduction reaction (ORR) activity and H 2 O 2 selectivity, yet achieving precise control over this process remains challenging. In this work, we introduce oxygen-doped carbon quantum dots (O-CQDs) into NiSe 2 nanoparticles/nanosheets to regulate the electronic structure of Ni active sites. This optimization promotes favorable O 2 adsorption and reduces the energy barrier for • OOH formation, thereby significantly boosting the electrocatalytic production of H 2 O 2 via the two-electron (2e – ) ORR pathway. Combined spectroscopic analysis and density functional theory calculations reveal that the O-bridged interface facilitates electron transfer to surface Ni sites, strengthening O 2 adsorption in an “end-on” configuration and favoring the 2e – ORR mechanism. The resulting O-bridged NiSe 2 /CQDs catalyst exhibits outstanding 2e – ORR performance under alkaline conditions, achieving a high H 2 O 2 production rate of 7458.24 mmol g cat –1 h –1 at 31.25 mA cm –2 and a Faradaic efficiency of 92.88% at 0.5 V. The efficient degradation of the Rhodamine B and Methylene Blue is achieved by utilizing the electrolyte obtained after the H 2 O 2 electrosynthesis process as a Fenton reagent. This study demonstrates that rational tailoring of interfacial charge distribution in hybrid catalysts provides an effective strategy for enhancing catalytic performance, offering a promising design principle for advanced electrocatalysts.
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FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
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2024
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IF 2.1
Huanhuan Lu,Yongfeng Zhao,Tong Wang,Qiyu Wang,Chunyan Sun
In this study, a highly selective and sensitive composite fluorescence sensor (Y-CODs @PVDF@PVP) was developed for the quantitative and visual detection of Hg2+ by electrostatic spinning carbon quantum dots (CQDs) with polyvinylidene fluoride (PVDF) and polyethylene pyrrolidone (PVP). The Y-CODs @PVDF@PVP composite fluorescence sensor exhibited strong yellow fluorescence under ultraviolet light (365 nm), demonstrating stable detection capability for mercury (II) in water samples. The morphology, chemical composition, and optical properties of Y-CODs @PVDF@PVP were thoroughly investigated. Different quenching effects were observed in Y-CODs @PVDF@PVP based on varying concentrations of Hg2+, enabling accurate determination of Hg2+. The achieved detection limit was 9.27 nM. Both static quenching and dynamic quenching mechanisms contributed to the observed results. Notably, the method successfully detected Hg2+ in real water samples from Beichuan Lake as well as rice samples, yielding satisfactory outcomes. Furthermore, when combined with software image analysis, quantitative and visual detection of field Hg2+ levels was accomplished using the composite fluorescence sensor. This research provides valuable insights for developing portable sensors aimed at monitoring harmful substances in water.
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