MOLECULAR PHARMACEUTICS
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2020
·
IF 4.321
Zhengzhong Wu,Bin Chen,Ziying Gan,Fan Chen,Xianglin Luo
The effective accumulation at tumor sites and endocytosis by tumor cells for anticancer agents in carriers are essential in successful cancer therapy, and both of the processes are affected by the surface charge of drug carriers. In this study, vitamin C (VC) was employed as an “exogenous switch” to trigger the surface charge conversion of DOX-loaded micelles to obtain a better antitumor effect. T micelles formed by poly(ε-caprolactone)-b-poly(N,N-diethylaminoethyl methacrylate)-ss-b-poly(2-methacryloyloxyethyl phosphorylcholine) (PCL–PDEA-ss-PMPC) turned their ζ potentials from +1 mV to +18 mV under treatment of 20 mM VC, while the ζ potentials of control R micelles formed by PCL-ss-P(DEA-r-MPC) almost remained unchanged under the same condition. DOX-loaded T@DOX and R@DOX had high DLCs of 12% and 13.8%, respectively, and both showed an accelerated drug release in a reductive environment (10 mM GSH or 20 mM VC) at pH 5.0. Notably, due to the surface charge conversion and fast drug release triggered by VC, T@DOX/VC (T@DOX was pretreated by VC) showed an enhanced cytotoxicity and cellular uptake superior to T@DOX, R@DOX, and R@DOX/VC. T@DOX/VC also displayed the in vivo antitumor effect well, which was comparable to DOX·HCl but with less toxic side effects than DOX·HCl. In summary, VC as an exogenous trigger can induce a better antitumor effect of drug-loaded micelles with a suitable polymer structure by charge conversion, and T@DOX/VC has shown to be as a promising approach to achieve potent treatment of tumors.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 413
·期 20
·5239-5249
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IF 4.157
Yin Chenhui,Chen Ligang,Niu Na
A sensitive and effective strategy for the detection of cytochrome c (Cyt c) and trypsin was developed using biomass nitrogen-doped carbon quantum dots (N-CQDs) as the fluorescence probe. N-CQDs were synthesized through a one-pot hydrothermal method by utilizing cellulolytic enzyme lignin as the carbon source and ammonia as the solvent and nitrogen source. The obtained N-CQDs had good water solubility and stable optical properties. The introduction of nitrogen increased fluorescence quantum yield (QY) to 8.23%, which was almost four times as high as that before nitrogen doping. The N-CQDs were fabricated as a label-free biosensor to detect Cyt c and trypsin. The fluorescence of N-CQDs was quenched with positively charged Cyt c due to electrostatic induction aggregation and static quenching. However, Cyt c tended to be hydrolyzed into small peptides in the presence of trypsin, which caused fluorescence recovery of the N-CQDs/Cyt c complex. A wide linear response range was achieved for Cyt c within 1–50 μM and the developed N-CQDs/Cyt c complex displayed a linear response for trypsin within 0.09–5.4 U/mL. The detection limits were 0.29 μM for Cyt c and 0.013 U/mL for trypsin, respectively. Furthermore, this assay had been applied to Cyt c and trypsin detection in serum samples with the recoveries in the range of 94.6–98.5% and 95.5–102.0%, respectively. The established method was sensitive, selective, easy to operate, and low cost, which proved its potential application in clinical diagnosis. Graphical abstract
The synthesis and fluorescence mechanism of N-CQDs and the strategy for Cyt c and trypsin detection
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ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Zhendong Yu,Jiachen Ma,Jinlan Dai,Shiyu He,Xiaoyi Huang,Yuancai Lv,Yifan Liu,Chunxiang Lin,Junfeng Chen,Minghua Liu
In this study, a bimetallic composite catalyst (Co–Fe@C) was fabricated with calcination at high temperature (800 °C) by using Co-MIL-101 (Fe) as the precursor. The characterization results showed that the resulted Co–Fe@C composite mainly consisted of carbon, FeCo alloys, Fe 3 O 4 , Co 3 O 4 and FeO, and owned evident magnetism. In addition, the Co–Fe@C was employed to activate the peroxydisulfate (PDS) to degrade a representative organic pollutant ( p -arsanilic acid, p -ASA) and the main factors were optimized, which involved 0.2 g L −1 of catalyst dosage, 1.0 g L −1 of PDS dosage and 5.0 of initial pH. Under the optimal condition, Co–Fe@C/PDS system could completely degrade p -ASA (20 mg L −1 ) in 5 min. In the Co–Fe@C/PDS system, SO 4 − · , Fe(IV) and ·OH were the main species during p -ASA degradation. Under the attack of these species, p -ASA was first decomposed into phenols and then transformed into the organics acids and finally mineralized into CO 2 and H 2 O through a series of reactions like hydroxylation, dearsenification, deamination and benzene ring opening. Importantly, most of the released inorganic arsenic species (93.40%) could be efficiently adsorbed by the catalyst.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2021
·Vol. 51
·期 1
·68-76
·
IF 1.938
Cui Xinying,Liu Li,Liu Xiaoyang,Li Yixin,Feng Yi,Ma Lijie,Liu Liangyu,Xue Ying,Zhu Yanchao,Wang Xiaofeng
Rice husks (RHs) are rich in silica and organic carbon components, which have been widely applied in lithium ion batteries. However, the natural structure of uneven dispersion between SiO 2 and amorphous C in RHs leads to poor electrical conductivity and structural integrity. In this work, SiO 2 /C composites were prepared by mechanical mixing and high-temperature carbonization from RHs, with coal tar electronic pitch (CTEP) or polyvinyl chloride (PVC) as the carbon coating agent, which imparted some improvement in cycling performance, initial coulombic efficiency (ICE), and rate performance. Compared with the high electrical conductivity of CTEP, PVC with low viscosity coated uniformly the surface of BM-SiO 2 /C, which is beneficial to providing both elastic and mechanical stability and keeping the structural integrity. BM-SiO 2 /C-PVC-6 exhibits a more stable cycling performance and higher specific capacity of 730 mA h g -1 after 100 cycles at 0.1 A g -1 , with the ICE of 60%. Hence, the application of carbon coating agent plays a vital role in improving the electrochemical performance of SiO 2 /C composites. PVC with excellent coating performance was selected to coat RHs-SiO 2 /C and the electrochemical performance was enhanced, which provides a method of converting biomass material into a useful storage device.
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CELLULOSE
·
2019
·Vol. 27
·期 2
·799-823
·
IF 3.917
Lv Wei,Liao Yuhe,Zhu Yuting,Liu Jing,Zhu Changhui,Wang Chenguang,Xu Ying,Zhang Qi,Chen Guanyi,Ma Longlong
The cleavage of linkages of lignocellulose is important for its valorization. The linkage cleavage of cornstalk hydrolysis residue was investigated over catalysts (Ru/C + MgCl 2 ) in EtOAc/H 2 O solvents. The results show that almost hydrogen bonds, C–C bonds, ether and ester bonds in the matrix of lignin and cellulose were broken, accompanying 80.6% of lignin and 98.5% of cellulose conversion, and obtaining 37.5% of aromatic monomers and 28.8% of lignin oligomers. In the reaction system, biphasic EtOAc/H 2 O solvents exhibited an effect on cleaving the intermolecular linkages between lignin and cellulose. MgCl 2 showed limited abilities of breaking the α-O-4 and β-O-4 linkages in lignin and limited β-1, 4-glycosidic and hydrogen bonds in cellulose were cleaved over Ru/C catalyst. The cleavage of C–O linkages (α-O-4, β-O-4, 4-O-5) and C–C bonds (α-β, β-5) in lignin were mainly dependent on Ru/C catalyst. Much C–O and the stubborn C–C linkages of β-5, β-1 and 5-5 were significantly disrupted by the synergistic effect between MgCl 2 and Ru/C. However, MgCl 2 exhibited great contribution to breakage of β-1, 4-glycosidic linkage, hydrogen bonds and sugar ring of cellulose. The linkage of β-1, 4-glycosidic, hydrogen bonds and C–C in C5/C6 sugars were significantly broken. The increased yield of products was evidently due to the synergistic effect of Ru/C combined with MgCl 2 .
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RSC Advances
·
2019
·Vol. 9
·期 68
·39561-39571
·
IF 3.049
Fahim A. Qaraah,Samah A. Mahyoub,Mahmoud Elsayed Hafez,Guangli Xiu
Herein, we fabricated a C and N co-modified Nb2O5 nanonet structure (C–N/Nb2O5NNs) from niobium oxalate using 2-methylimidazole (Hmim) as a source for C and N via a simple hydrothermal route. The obtained nanonets are robust and cost-effective with excellent recycling stability. Compared with N-doped TiO2 (N-TiO2) and a Nb2O5 control sample (Nb2O5-CS), the resulting nanonets exhibited the highest performance toward the photocatalytic degradation of Rhodamine B (RhB) upon visible light irradiation (λ > 420 nm). Through this study, we revealed that the synergetic effects of C and N on the nanonet surface, which were effectively incorporated into the surface of the Nb2O5 nanonet structure, not only remarkably enhanced the visible light response by decreasing the bandgap to 2.9 eV but also improved the light utilization efficiency and photo-induced electron–hole pair separation efficiency of our nanonet structure. We also proposed that the presence of carbonate species (COx) and nitrogen species (NOx) increased the population of generated holes (h+) that had the key role in the photodegradation mechanism of RhB, suggesting reasonable importance for the modification of Nb2O5 with C and N. This synergism offers a new view to reveal the origin of photodegradation processes, introducing h+ as a key intermediate. Our approach provides a new insight to design 2D nanostructures with potential applications in catalysis, solar energy conversion, and environmental protection.
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高影响因子
CARBON
·
2019
·
IF 7.466
Shakiaz Ahmad,Chao Yang,Wenyu Xie,Zhibo Deng,Heng Zhang,Yunlong Zhao,Xintai Su
The integration of two transition metals with carbon materials provides a great potential to boost the catalytic and electrochemical properties of supercapacitor . However, a scalable fabrication of such composite materials remains a challenge. Here, ternary composites of NiS–NiCo 2 O 4 @C nanosheets were derived from nickel and cobalt oleate using Na 2 SO 4 as both hard template and sulfur source. The NiS–NiCo 2 O 4 @C composites were then tested as catalysts toward rapid reduction of 4-nitrophenol (4-NP) and as electrode materials for supercapacitors. It was found that the catalytic and electrochemical properties of the composites were tuned by adjusting the ratios of Co to Ni and annealing temperature. The optimized composite showed the highest reduction rate constant for 4-NP reduction (1.78 min −1 ). In addition, this composite has also shown high specific capacitance of 1411 F g −1 at 1 A g −1 and 99.5% capacity retention after 2000 continuous charge-discharge cycles at a current density of 3 A g −1 , which is much higher than their respective monometallic Co and Ni composites. Furthermore, the ASC device (CN14//AC) achieved a high energy density of 37.2 W h kg −1 at a power density of 799.9 W kg −1 , and a good cycling performance of retention(89%) after 5000 cycles.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Jingtao Bi,Xin Huang,Jingkang Wang,Ting Wang,Hao Wu,Jinyue Yang,Haijiao Lu,Hongxun Hao
In this work, to simultaneously remove organic dyes and Pb(II) from wastewater, a series of magnetic Fe 3 O 4 @C@TiO 2 -nanotube composites were designed and successfully synthesized via a new facile oil-phase cyclic magnetic adsorption (OCMA) method. The structural properties of the synthesized composites were investigated by different characterization methods systematically. It was found that Fe 3 O 4 was uniformly deposited on the inner walls of TiO 2 nanotubes. Although a Type III band alignment was formed in the catalysts, Fe 3 O 4 @C@TiO 2 -nanotube composites exhibited enhanced light absorbing ability and enlarged absorption edge due to efficient separation of h + and e − , which was verified by UV–Vis (Ultraviolet–visible) and PL (Photoluminescence) spectra. Decontamination experiments of 1FeCTi showed that more than 98% of RhB and about 92% of Pb(II) ions could be removed through adsorptive removal in the dark equilibrium period and further elimination during the illuminating period. The pseudo-first-order model, L-H model and adsorption-reaction model were established to describe the adsorption of Pb(II) in the dark, photodegradation of RhB and further elimination of Pb(II), respectively. A four-step mechanism was proposed to describe the decontamination process of Pb(II) during the illuminating period according to the final forms of Pb (Pb δ1 , Pb δ2 , Pb 0 and PbO). Finally, it was found that the photocatalytic activity would be maintained in the recycle experiments due to the existence of 1FeCTi@PbO heterostructure.
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高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Shuqi Fang,Zhibing Cui,Yuting Zhu,Chenguang Wang,Jing Bai,Xinghua Zhang,Ying Xu,Qiying Liu,Lungang Chen,Qi Zhang,Longlong Ma
Herein, we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel. Compared with the conventional method, which includes carbonization , activation, impregnation and reduction, the entire preparation process was simplified to two steps, which was more straightforward. This synthesis method was green as Ni/C can be prepared without any additional chemical and the self-reduction process was realized in N 2 , which can avoid using H 2 thus averting some problems such as storage, transportation and safety of H 2 . Meanwhile, the size and dispersion of Ni particles can be controlled by changing carbonization temperature. The synthesis mechanism of Ni/C catalyst with self-reduction was investigated, which was mainly attributed to the carbon and reducing gas produced during the carbonization process. For the catalytic performance of GVL synthesis, a high yield (94.5%) can be obtained and it exhibited good stability up to 5 cycles without obvious loss of catalytic activity .
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高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Xing Xu,Lei Lai,Jiahong Jiang,Zhiqiao He,Shuang Song
Nitrogen-doped carbon-wrapped C,N-codoped TiO2 (CN@C,N-TiO2) was successfully prepared using a facile and efficient method involving hydrolysis and calcination under Ar using tetrabutyl titanate and 2,6-diaminopyridine as the precursors. X-ray photoelectron spectroscopy (XPS) and valence band XPS measurements reveal the successful codoping of interstitial carbon and nitrogen into TiO2, which leads to a visible-light absorption of up to ∼550 nm in the UV–vis diffuse reflectance spectra. Raman spectra and high-resolution transmission electron microscopy results show that N-doped carbon exists on the surface of C,N-TiO2, which gives rise to the efficient separation of photoexcited charge carriers, as determined by photoluminescence and electrochemical impedance spectroscopy. Benefiting from the combined effects of a surface-coated N-doped carbon layer and C,N-codoping, the photocatalyst calcined at 450 °C exhibits remarkable visible-light activity toward the hydrogen evolution reaction in the water splitting process with a H2 production rate of 833.2 μmol h–1 g–1 under 94 mW cm–2 visible-light illumination (λ > 420 nm). Moreover, the representative CN@C,N-TiO2 sample can maintain its activity for at least 40 h.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Qi Zhang,Liangyun Yu,Chenchen Xu,Jinyong Zhao,Haiyang Pan,Ming Chen,Qi Xu,Guowang Diao
Herein, a kind of Fe 3 O 4 @C@Ru hybrid nanocomposites was successfully synthesized by a three-step process. The as-prepared products were characterized by X-ray powder diffraction, transmission electron microscopy , high-resolution transmission electron microscopy , energy dispersive spectroscopy , X-ray photoelectron spectroscopy, UV–visible diffuse reflectance spectrometry and photoluminescence emission spectrometry . The Ru nanoparticles loaded on the surface of carbon shell on Fe 3 O 4 @C nanospheres were nearly spherical with an average diameter of less than 5 nm. The photodegradation of methylene blue (MB) was carried out under the irradiation of simulated visible light to investigate the catalytic activity of the introduced nanomaterial . The results showed that the catalytic activity of Fe 3 O 4 @C@Ru nanocomposites in the MB photodegradation was higher than that of Fe 3 O 4 nanospheres or of Fe 3 O 4 @C nanospheres, as they could degrade 92.70% of the dye in 140 min of simulated sunlight irradiation without any other oxidant or reductant. The photodegradation reaction was first-order with the rate constant of 0.0176 min −1 at room temperature . The degradation rate of Fe 3 O 4 @C@Ru nanocomposites decreased very slightly after five cycles. Furthermore, they could be easily separated and recycled by using an external magnet. It indicated that the magnetically recoverable Fe 3 O 4 @C@Ru nanocomposites had a very broad application prospect in the field of environmental protection.
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高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Qingfeng Zhou,Yun Gong,Keyu Tao
Binary metal compounds have higher conductivity and richer redox reactions due to the co-existence and synergism of different transition metals. Besides, carbon in composite materials has the advantage of enhancing electronic conductivity to promote fast electron transmission. Herein, a series of Ni m P n /C, Ni 2 P/C, Co 2 P/C and Ni x Co 2-x P/C nanohybrids with different Ni/Co molar ratios were synthesized by in-situ calcination/phosphorization of MOF precursors. These nanohybrid materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive spectrometer and electrochemical tests. The NiCoP/C material possesses a granular structure with NiCoP nanoparticles anchored in a large number of carbon. Taking advantage of the bimetallic synergism and carbon anchoring effect, the as-prepared NiCoP/C sample delivers the most prominent specific capacities of 775.7C g −1 at 1 A g −1 , and 582.4C g −1 at 20 A g −1 (20-fold) with a superior rate capability of 75.1% retention, much superior to those of the corresponding Ni m P n /C, Ni 2 P/C, Co 2 P/C, other Ni x Co 2-x P/C samples and various reported metal phosphide nanostructures/nanocomposites. Furthermore, the constructed NiCoP/C//activated carbon asymmetric supercapacitor can exhibit a high energy density of 47.6 Wh kg −1 at a power density of 798.9 W kg −1 , which was superior to those previously reported of Ni/Co phosphide nanomaterials.
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危险品化学品经营许可证（带存储）