APPLIED SURFACE SCIENCE
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2019
·
IF 5.155
Yan Jiang,Feiqiang Qu,Lin Tian,Xiaofei Yang,Zhaoyong Zou,Zixia Lin
The solar-to‑hydrogen conversion via semiconductor-based photocatalytic water splitting has triggered the search for cost-effective, high-performance photocatalytic materials. Graphitic carbon nitride (g-C 3 N 4 ) has proven to be a promising metal-free photocatalyst for the hydrogen evolution reaction (HER), however, bulk g-C 3 N 4 suffers from limited HER efficiency owing to its disadvantages including fast electron-hole recombination, low conductivity and irregular microstructure. Herein, we report a supramolecular chemistry-based approach to construct g-C 3 N 4 nano-architectures by calcining the pre-organized complexes originating from the copolymerization of two symmetrical precursors, melamine and trithiocyanuric acid. The resultant g-C 3 N 4 micro-/nanostructures not only effectively induce enhanced visible light-harvesting property but also accelerate the electron-hole separation and charge carrier transfer, leading to highly improved HER performance. X-ray photoelectron spectroscopy (XPS) analysis confirms the chemical environment of different elements, while in-situ electron paramagnetic resonance (EPR) characterizations reveal the types of oxygen-containing radicals and charge carrier dynamics. Compared to pristine g-C 3 N 4 , the optimal large-aspect-ratio g-C 3 N 4 sheets derived from ethanol show the fastest HER rate of 1144 μmol·h −1 ·g −1 . The improvement of photocatalytic activity can be ascribed to synergistic effects of extended visible light absorption, boosted charge transfer and more active catalytic sites for HER in modified g-C 3 N 4 materials.
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高影响因子
SENSORS
·
2013
·Vol. 13
·期 1
·1064-1075
·
IF 1.953
Zhenzhu Zheng,Jing Han,Wensheng Pang,Juan Hu
With an internal transcribed spacer of 18 S, 5.8 S and 26 S nuclear ribosomal DNA (nrDNA ITS) as DNA marker, we report a colorimetric approach for authentication ofPseudostellaria heterophylla(PH) and its counterfeit species based on the differentiation of the nrDNA ITS sequence. The assay possesses an unlabelled G-quadruplex DNAzyme molecular beacon (MB) probe, employing complementary sequence as biorecognition element and 1:1:1:1 split G-quadruplex halves as reporter. In the absence of target DNA (T-DNA), the probe can shape intermolecular G-quadruplex structures capable of binding hemin to form G-quadruplex-hemin DNAzyme and catalyze the oxidation of ABTS2−to blue-green ABTS•−by H2O2. In the presence of T-DNA, T-DNA can hybridize with the complementary sequence to form a duplex structure, hindering the formation of the G-quadruplex structure and resulting in the loss of the catalytic activity. Consequently, a UV-Vis absorption signal decrease is observed in the ABTS2−-H2O2system. The “turn-off” assay allows the detection of T-DNA from 1.0 × 10−9to 3.0 × 10−7mol·L−1(R2= 0.9906), with a low detection limit of 3.1 × 10−10mol·L−1. The present study provides a sensitive and selective method and may serve as a foundation of utilizing the DNAzyme MB sensor for identifying traditional Chinese medicines.Keywords:G-quadruplex DNAzyme;molecular beacon;colorimetric;Pseudostellaria heterophylla
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2012
·
IF 3.461
Huanhuan Ji,Fei Chang,Xuefeng Hu,Wei Qin,Jiaowen Shen
Graphitic carbon nitride (g-C 3 N 4 ) was synthesized by directly thermal condensation of dicyandiamide and characterized by XRD, XPS, SEM, TEM and FT-IR. Then the as-prepared catalyst was employed to degrade priority pollutant 2,4,6-trichlorophenol (2,4,6-TCP) under visible light irradiation ( λ > 420 nm). The 2,4,6-TCP could be completely mineralized over g-C 3 N 4 , and the pseudo-first-order rate constant for 10 −4 M 2,4,6-TCP degradation was 0.70 h −1 in the presence of 1 g/L catalyst. O 2 - / OOH was identified as the most important reactive species contributing to 2,4,6-TCP degradation in air. Meanwhile, valence band holes (VB holes) of g-C 3 N 4 was observed to play important roles for the degradation of 2,4,6-TCP at N 2 gas ambient when metal ions were added as electron acceptors. The possible degradation pathway of 2,4,6-TCP was proposed.
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MOLECULAR PHARMACEUTICS
·
2013
·
IF 4.57
Yuanyuan Guo,Min Chu,Songwei Tan,Shuang Zhao,Hanxiao Liu,Ben Oketch Otieno,Xiangliang Yang,Chuanrui Xu,Zhiping Zhang
To overcome the P-glycoprotein (P-gp)-induced multidrug resistance (MDR) of cancer cells, a novel copolymer, chitosan-graft-d-α-tocopheryl polyethylene glycol 1000 (TPGS) (CT) was synthesized for doxorubicin (DOX) delivery by the P-gp inhibiting virtue of TPGS. DOX-loaded CT nanoparticles (NPs) were fabricated by a modified solvent extraction/evaporation method combined with ionic cross-linking to form a uniform particle size of 140–180 nm with ∼40% DOX loading efficiency. These drug-loaded CT NPs demonstrated a pH-responsive release behavior, and DOX was released more quickly under low pH values. Significant cell cytotoxicity was observed on the human hepatocarcinoma cells (HepG2 and BEL-7402) and human breast adenocarcinoma cells (MCF-7). The cell cytotoxicity and apoptosis of drug-resistant cells (MCF-7/DOX and BEL-7402/5-Fu), was greatly enhanced as compared to Adriamycin. The IC50 value showed that DOX-loaded CT NPs could be 1.5–199-fold more effective than Adriamycin. This can be attributed to the P-gp blocking and down-regulation of ATP levels by the CT NPs. The potential of these NPs to act as an oral delivery system was also investigated. Both the pharmacokinetic properties and in vivo antitumor activity of DOX-loaded CT NPs were improved compared with Adriamycin.
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高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Chan Yu,Qing Zhou,Fan Xiao,Yihui Li,Hang Hu,Ying Wan,Zifu Li,Xiangliang Yang
Doxorubicin (DOX), a kind of wide-spectrum chemotherapeutic drug, can cause severe side effects in clinical use. To enhance its antitumor efficacy while reducing the side effects, two kinds of nanoparticles with desirable compositions and properties were assembled using optimally synthesized hydroxyethyl starch-grafted-polylactide (HES-g-PLA) copolymers and utilized as partner nanocarriers. The large empty HES-g-PLA nanoparticles (mean size, ca. 700 nm), at an optimized dose of 400 mg/kg, were used to block up the reticuloendothelial system in tumor-bearing mice 1.5 h in advance, and the small DOX-loaded HES-g-PLA nanoparticles (mean size, ca. 130 nm) were subsequently applied to the mice. When these partner nanocarriers were administered in this sequential mode, the released DOX had a significantly prolonged plasma half-life time and much slower clearance rate as well as a largely enhanced intratumoral accumulation as compared to free DOX. In vivo antitumor studies demonstrated that the DOX-loaded HES-g-PLA nanoparticles working together with their partner exhibited remarkably enhanced antitumor efficacy in comparison to free DOX. In addition, these HES-g-PLA partner nanocarriers showed negligible damage to the normal organs of the treated mice. Considering safe and efficient antitumor performance of DOX-loaded HES-g-PLA nanoparticles, the newly developed partner nanocarriers in combination with their administration mode have promising potential in clinical cancer chemotherapy.
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高影响因子
E-POLYMERS
·
2016
·Vol. 16
·期 2
·99-109
·
IF 0.812
Xiu-Juan Wu,Ji-De Wang,Li-Qin Cao
Novel chitosan/diatomite (CS/DM) membranes were prepared by phase inversion technique to remove anionic azo dyes from wastewater. The fabricated composite membranes exhibited the combined advantages of inorganic substances, diatomites, and polysaccharides. These composite membranes were characterized through Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. The mechanical properties of the membranes were also evaluated. Adsorption experiments were conducted under varied initial dye concentration, solution pH values, contact time, and adsorbent dosage. The results indicate that pH 3 is the optimal pH value for Orange G adsorption. The CS/DM membranes exhibit the highest adsorption capacity of 588 mg g -1 and removal rate of 94% under an initial dye concentration of 200 mg l -1 , contact time of 6 h, and membrane dosage of 8 mg. Langmuir, Freundlich and Redlich-Peterson adsorption models were applied to describe the equilibrium isotherms at different dye concentrations. The equilibrium data was found to be fitted well to the Redlich-Peterson isotherm. Pseudo-first-order and pseudo-second-order kinetics models were used to describe the adsorption of membranes. The adsorption data were well explained by pseudo-second-order models, and also followed by the Elovich model. In addition, these membranes display high adsorption capacity and mechanical performance even after reused for seven times.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Gonge Tang,Cailan Zhao,Jie Gao,Hongliang Tan
It is of great importance to simply and sensitively detect hydrogen sulfide (H 2 S) because of its role in various physiological processes as well as its inherent toxicity. In this work, a colorimetric method for H 2 S detection was developed by employing terbium-G-quadruplex-hemin (Tb/G4-hemin) DNAzyme as a peroxidase mimic, which can catalyze H 2 O 2 -mediated oxidation of 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) to produce radical cation (ABTS + ). Compared with the G4-hemin DNAzyme promoted by K + and Na + , Tb/G4-hemin DNAzyme exhibits a higher catalytic activity. In the presence of Ag + , the peroxidase-like activity of Tb/G4-hemin DNAzyme can be inhibited significantly owing to the disruption of G-quadruplex structure. However, the addition of H 2 S can effectively suppress such negative behavior by competitive binding with Ag + , leading to the recovery of the peroxidase-like activity of Tb/G4-hemin DNAzyme, which can be reflected by an increase in absorbance signal of ABTS + . The absorbance of ABTS + was enhanced linearly with increasing H 2 S concentration from 20 nM to 2 μM. The detection limit for H 2 S is 13 nM, which is much lower than most of previous methods. Moreover, the proposed method possesses the features of simple preparation, easy reproducibility and good biocompatibility. Given the fine performances and striking properties, we believe that the Tb/G4-hemin DNAzyme would have a great promise for analytical applications.
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NEW JOURNAL OF CHEMISTRY
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2017
·Vol. 41
·期 23
·14602-14609
·
IF 3.269
Ke Xu,Hong Xu,Guangwei Feng,Jian Feng
NiS cocatalyst modified LaFeO3/g-C3N4 heterostructures were successfully prepared and their photocatalytic hydrogen evolution performance under visible light irradiation was presented. LaFeO3/g-C3N4/NiS composites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption desorption isotherms, UV-vis diffuse reflectance spectroscopy (DRS), transient photocurrent responses and electrochemical impedance spectroscopy (EIS). The results indicated that the LaFeO3/g-C3N4/NiS heterostructures had enhanced photocatalytic hydrogen evolution performance than pure g-C3N4, LaFeO3 and LaFeO3/g-C3N4. 5%-LaFeO3/g-C3N4/2%NiS exhibited the highest photocatalytic hydrogen evolution rate of 121 μmol g−1 h−1 under visible light, which was almost 60 times higher than the hydrogen evolution rate of 5%-LaFeO3/g-C3N4. The effective separation of photogenerated electron–hole pairs in the LaFeO3/g-C3N4 Z-scheme system with NiS as a cocatalyst enhanced the photocatalytic hydrogen evolution performance. This study provided a facile approach to prepare NiS modified LaFeO3/g-C3N4 heterostructures and to construct an effective photocatalytic system for hydrogen evolution under visible light irradiation.
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Nanomaterials
·
2024
·Vol. 14
·期 10
·896
·
IF 4.4
Ching-Wen Lou,Meng-Meng Xie,Yan-Dong Yang,Hong-Yang Wang,Zhi-Ke Wang,Lu Zhang,Chien-Teng Hsieh,Li-Yan Liu,Mei-Chen Lin,Ting-Ting Li
In this study, a Ti3C2MXene@g-C3N4composite powder (TM-CN) was prepared by the ultrasonic self-assembly method and then loaded onto a carbon nanofiber membrane by the self-assembly properties of MXene for the treatment of organic pollutants in wastewater. The characterization of the TM-CN and the C-TM-CN was conducted via X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FTIR) to ascertain the successful modification. The organic dye degradation experiments demonstrated that introducing an appropriate amount of Ti3C2MXene resulted in the complete degradation of RhB within 60 min, three times the photocatalytic efficiency of a pure g-C3N4. The C-TM-CN exhibited the stable and outstanding photocatalytic degradation of the RhB solution over a wide range of pH values, indicating the characteristics of the photodegradation of organic pollutants in a wide range of aqueous environments. Furthermore, the results of the cyclic degradation experiments demonstrated that the C-TM-CN composite film maintained a degradation efficiency of over 85% after five cycles, thereby confirming a notable improvement in its cyclic stability. Consequently, the C-TM-CN composite film exhibits excellent photocatalytic performance and is readily recyclable, making it an auspicious eco-friendly material in water environment remediation.
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高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Wenyu Bai,Guangpeng Ma,Xinpu Zhou,Tongtong Gao,Yu Luo,Di Yu,Shuang Wang
Traditional two-dimensional transition metal carbides/nitrides (MXene) have gained much academic concern due to their excellent physicochemical properties, but their susceptibility to self-stacking leads to poor cyclic stability. In this paper, an MXene-based electrode active material was successfully prepared. The generated modified PPy (g-PPy) increases the active site, increases the accessibility of ions, and can give full play to the pseudocapacitance. By the combination of modified PPy (g-PPy) nanoparticles with pseudocapacitive behavior polymerized in situ on sulfonated cellulose (SC) and MXene , not only the electrochemical performance was improved by exploiting the synergy between different electrode materials and different energy storage mechanisms, but also the MXene as a skeleton limited the volume expansion and contraction of PPy during charge/discharge cycles and the g-PPy and SC composites (g-PPy@SC) as a spacer supported the MXene layer, resulting in much higher cycle stability. Cycle stability of 98.4 % even after 10,000 cycle tests. In addition, a symmetric supercapacitor assembled from this electrode material maintains a stability of 84.4 % under 10,000 cycles at a low temperature of −40 °C. Therefore, this study provides a feasible method for the preparation of MXene-based electrodes with high cycling stability.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Muhua Chen,Yiping Liu,Ju Liu,Zilin Kan,Chenhui Sun,Yuqing Wang,Bo Fu,Xinbao Zhu
Recently, photocatalytic production of H 2 O 2 by semiconductors emerges as a green and potential method for green and sustainable H 2 O 2 synthesis. In this work, a g-C 3 N 4 /CAU-17 composite with heterojunction structure was fabricated. There is a tight interface contact between g-C 3 N 4 and CAU-17. And the g-C 3 N 4 nanosheets was uniformly wrapped on CAU-17 surface. In the hybrid catalyst, CAU-17 provides a high surface area for g-C 3 N 4 dispersion and the integration of g-C 3 N 4 boosts the visible light response. Results showed that the H 2 O 2 yield is 419.0 μmol . L −1. h −1 over g-C 3 N 4 /CAU-17 sample, which is 1.59 and 7.83 fold enhancements to bare g-C 3 N 4 and CAU-17 counterparts. This work sheds light on the design of CAU-17-based composite photocatalysts and provides insights into H 2 O 2 synthesis.
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Materials Today Chemistry
·
2024
·
IF 6.7
Junyu Chen,Yanqin Ma,Xinjian Cheng,Yufan Wu,Huizhi Chen,Cheng Liu
Natural polymer chitosan has many advantages, but the poor solubility limits its application. In this study, chitosan derivatives soluble in DCM, DMF, DMSO, H 2 O and other solvents were developed by introducing side chains into chitosan (CS). In addition, the fluorescent group on the side chain makes the chitosan derivative have the ability to detect 4-nitrophenol (4-NP). Firstly, a chain transfer agent containing C C (N3-NS) was synthesized with naphthalimide as the fluorescence unit. Then, using AIBN as initiator, an extensively soluble polymer with fluorescent moiety TP-NVP was synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) method using monomer N -vinyl pyrrolidone (NVP). Finally, the C C of TP-NVP was used to react with –NH 2 on CS to prepare PVP-g-chitosan, so that more CS was “pulled” by TP-NVP into the solvent. The solubility of the synthesized CS-PVP probe can be adjusted by adjusting the amount of NVP, up to 17.6 mg/mL. At the same time, the synthesized CS-PVP had a good detection effect on 4-NP, and the detection limit (LOD) was 0.054 μM. The HOMO-LUMO energy level of the probe was calculated by cyclic voltammetry (CV). In addition, CS-PVP was successfully loaded on a low background fluorescent test paper to achieve real-time visual intelligent determination of 4-NP in real samples with the help of a color scanning APP of a smartphone.
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危险品化学品经营许可证（带存储）