APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
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IF 11.698
Xue Bai,Yanyan Du,Xiaoyun Hu,Yudong He,Chunliang He,Enzhou Liu,Jun Fan
A novel RP-MoS 2 /rGO nanocomposite as low-cost, environmental sustanable, stability and high-performance photocatalyst was successfully fabricated for the first time through a facile two-step hydrothermal method. Even without a noble-metal cocatalyst, the introduction of MoS 2 /rGO hybrid made RP exhibit excellent photocatalytic performance, including photoreduction of Cr (VI) and photooxidation of different organic pollutants, owing to the increased number of excited electrons/holes and enhanced separation efficiency of charge carriers. Importantly, the synergy of photocatalytic reduction and oxidation, as well as photocatalysis and adsorption played an important role in enhancing photocatalytic activity and reaching a high efficiency. Besides, the chemical structure of the RP-MoS 2 /rGO with P–S and P O bands ensure the stability of the nanocomposite materials. Overall, the photocatalytic elimination of the Cr (VI)-Organic molecule coexistence system in this work shows promising application to treatment the reality wastewater.
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高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2019
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IF 5.589
Xu Yan,Mengmeng Song,Mo Zhou,Chunlian Ding,Zhongren Wang,Yunyan Wang,Weichun Yang,Zhihui Yang,Qi Liao,Yan Shi
CuO nanoparticles (NPs) released into aqueous environments induce metal toxicity, which generally exerts negative effects on various organisms and leads to great challenge for wastewater biotreatment. In this study, a promotion effect of CuO NPs on biological process was first found. Cr(VI) reduction by Cupriavidus basilensis B-8 (hereafter B-8) was enhanced in the presence of CuO NPs. The efficiency of Cr(VI) bioreduction was much higher with B-8 and CuO NPs (approximately 100%) than with B-8 (approximately 37.6%) and CuO NPs (39.9–44.7%) alone, indicating a stimulatory effect of CuO NPs on Cr(VI) reduction by B-8. Our material analyses revealed different response mechanisms of B-8 to Cr(VI), with and without CuO NPs. The addition of CuO NPs influenced the interaction of Cr(VI) with the N-, P-, S-, and C-related functional groups of B-8. Transcriptomic analysis indicated that multiple mechanisms, including Cr(VI) uptake and reactive oxygen species detoxification, were induced by Cr(VI). Many genes involved in various metabolic processes were significantly upregulated by the addition of CuO NPs. To a certain extent, the pressure of DNA repairment by B-8 induced by Cr(VI) was also alleviated by the presence of CuO NPs. They contributed to facilitate B-8 growth and enhance Cr(VI) reduction, even with 50 mg/L Cr(VI). This study not only elaborated the mechanisms of bacterial Cr(VI) reduction when enhanced by CuO NPs, but also provided a novel perspective for wastewater biotreatment.
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PubMed
高影响因子
Journal of Energy Chemistry
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2014
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IF 0
Yong Xie,Rui-Xia Yang,Nian-Yu Huang,Hua-Jun Luo,Wei-Qiao Deng
We reported a bifunctional material, Cr-salen implanted conjugated microporous polymer (Cr-CMP), which is able to capture excellent CO 2 amounts and has a remarkable catalytic activity towards the cycloaddition reaction of CO 2 to epoxides forming cyclic carbonates at mild conditions without additional solvents. This heterogeneous Cr-CMP catalyst has a superior catalytic activity to its related homogeneous catalyst and can be reused more than ten times without a significant decrease in catalytic activity.
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Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 12
·6586-6591
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IF 7.443
Hongfei Shi,Huaqiao Tan,Wan-bin Zhu,Zaicheng Sun,Yuejia Ma,Enbo Wang
A series of Cr-doped Bi4Ti3O12/Bi2Ti2O7 (BTO) heterostructure fibers have been synthesized via a one-step, facile and economical electrospinning/calcination process. SEM and TEM results reveal that the diameters of the as-prepared fibers are 100 ± 30 nm. The light adsorption of Bi4Ti3O12 and Bi2Ti2O7 in the fibers has been remarkably improved by Cr doping. With increased Cr doping, XRD and XPS show that the amount of Bi2Ti2O7 increases in the fibers. As a result, the Bi4Ti3O12/Bi2Ti2O7 heterojunction structure is enhanced, which further promotes the charge separation of photogenerated charge carriers. Photocatalytic tests indicated that the as-prepared Cr-doped Bi4Ti3O12/Bi2Ti2O7 fibers exhibit good photocatalytic activity for photodegradation of methyl orange (MO) under visible-light irradiation.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2015
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IF 2.729
Xiuli Song,Tailai Yang,Haiyan Du,Wenyan Dong,Zhenhai Liang
Transition metal mixed oxides of Mn and Cr with the nominal compositional formula Mn x Cr 1 − x O 1.5 ( x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were obtained by the thermal decomposition method. The powders were analyzed by SEM (scanning electron microscopy), XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy). The electrochemical properties of the Mn x Cr 1 − x O 1.5 electrodes for the OER (oxygen evolution reaction) in alkaline solution were evaluated by LSV (linear sweep voltammetry), staircase voltammetry and chronoamperometry . The results indicated that the mixed oxides were solid solutions of Mn 2 O 3 (bixbyite) and Cr 2 O 3 (eskolaite), and when x = 0.2, the catalyst had better catalytic activity in the OER process than did that of single Mn 2 O 3 and Cr 2 O 3 . At the high potential region (1.0 V vs Ag/AgCl), the current density of the Mn 0.2 Cr 0.8 O 1.5 electrode was ~ 80 times higher than that of Mn 2 O 3 and ~ 9 times higher than Cr 2 O 3 , and its overpotential ( η = 367.3 mV at a current density of 1.0 mA·cm − 2 ) was considerably lower than that of single Mn 2 O 3 ( η = 996.5 mV) and Cr 2 O 3 ( η = 648.5 mV) catalysts and was comparable to the precious metal oxide IrO x . The stability testing indicated that the mixed oxides had good stabilities in strong alkaline solution during the OER process.
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APPLIED CATALYSIS A-GENERAL
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2014
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IF 3.674
Siyang Tang,Zhen Liu,Xiaowei Yan,Ning Li,Ruihua Cheng,Xuelian He,Boping Liu
An extensive experimental kinetic study of ethylene trimerization was carried out over the Chevron-Phillips homogeneous catalyst system [Cr(2-ethylhexanoate) 3 (Cr(2-EH) 3 )/2,5-dimethylpyrrole (DMP)/co-catalyst/halide] in terms of the effects from organic halide additives, type of co-catalysts, temperature, ethylene pressure, Cr concentration, and ligand/Cr molar ratio, etc. Ten kinds of organic halides and four kinds of organometallic co-catalysts were tested in this work. The 1,1,2,2-tetrachloroethane (TCE) and triethylaluminum (TEA) were found to be the best candidates for this catalyst system. The molar ratios of DMP/Cr, TCE/Cr and TEA/Cr showed a strong impact on the catalytic performance of ethylene trimerization. A detailed catalytic kinetic behavior and the kinetic simulation were also performed for the first time over this catalyst system. It could be extrapolated that the dependency of the trimerization reaction rate on ethylene concentration and catalyst concentration is second-order and first-order, respectively. The apparent activation energy of this reaction is 99.1 kJ/mol at the temperature range from 65 °C to 95 °C. And the apparent reaction rate equation is achieved as follows:. R = 5.23 × 10 18 exp − 99.1 R T C ca 1.12 C e 1.95 .
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2014
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IF 3.84
Wangyao Zhang,Yang Yang,Fenfen Li,Guosheng Song,Yong Shao,Ruizhuo Ouyang,Lina Xu,Weiwei Li,Yuqing Miao
A simple one-step method was successfully developed to prepare stable nanosized Ni(OH) 2 @Cr(OH) 3 hybrid particles by just adding NaOH to a mix solution containing Ni(NO 3 ) 2 and Cr(NO 3 ) 3 at room temperature. In contrast, under the exact same conditions, flocculent Ni(OH) 2 or Cr(OH) 3 precipitate was obtained after the addition of equivalent NaOH in a solution containing same amount of Ni(NO 3 ) 2 or Cr(NO 3 ) 3 as in the mix solution. The interaction between Ni(II) and Cr(III) ions was believed to make major contribution to the formation of stable Ni(OH) 2 @Cr(OH) 3 nanohybrid without aggregation to large-size particles. The prepared Ni(OH) 2 @Cr(OH) 3 hybrid nanoparticles were well characterized by the scanning electron microscopy (SEM), the transmission electron microscopy (TEM), X-ray diffraction (XRD), and electrochemical measurements with results showing uniform size, smooth surface, good monodispersibility, fast electron transfer rate as well as promising electrocatalytic properties toward glucose (Glu) and cysteine (Cys) oxidation. The presence of a small amount of Cr(OH) 3 in the composite not only improved the stability and monodispersibility of the Ni(OH) 2 @Cr(OH) 3 hybrid particles, decreased their size to nanoscale, but also exerted positive effect to the electrochemical properties of the obtained Ni(OH) 2 based nanomaterials like the electron transfer rate and the electrocatalytic activity. Satisfactory electrocatalytic performances of the Ni(OH) 2 @Cr(OH) 3 nanohybrid toward Glu and Cys oxidations were achieved, respectively, in certain concentration ranges with acceptable detection limits and correlation coefficients, suggesting the potential facilitation of electrocatalysis toward other small molecules by the newly prepared Ni(OH) 2 @Cr(OH) 3 nanohybrid.
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ChemCatChem
·
2017
·Vol. 9
·期 17
·3364-3373
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IF 4.803
Qiaoqiao Sun,Ruihua Cheng,Zhen Liu,Xuelian He,Ning Zhao,Boping Liu
Graphical The fluorine effect : Fluorinated Phillips catalysts (Cr/F-SiO 2 ) exhibit an enhanced reactivity towards ethylene polymerization and copolymerization. DFT calculations show that the difference of the Gibbs free energy barriers between chain transfer and chain propagation increased after the introduction of the fluoride onto the silica surface, which is in accordance with the increased molecular weight of the polyethylene formed using the Cr/F-SiO 2 catalyst. In this work, a fluoride-modified Phillips catalyst was investigated by using combined experimental and computational methods. The addition of fluoride to the Phillips Cr/SiO 2 catalyst can increase the activity of the catalyst calcined at a low temperature and the molecular weight of the polyethylene product. DFT calculations were performed to show that the difference of the Gibbs free energy barriers between chain transfer and chain propagation increased after the introduction of the fluoride onto the silica surface, which is in accordance with the increased molecular weight of the polyethylene produced by the fluoride-modified Phillips Cr/F-SiO 2 catalyst. The computational results also reflect the increase of the activity of the ethylene/1-hexene copolymerization after the introduction of fluoride, although the modification has little effect on the regioselectivity of the produced ethylene/1-hexene copolymer. Moreover, copolymers produced by the fluoride-modified Phillips catalyst with more short-chain branches (SCBs) in the high-molecular-weight fraction and a significant enhancement of the environmental stress crack resistance can be explained from the results of the DFT calculations.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2017
·Vol. 134
·期 18
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IF 1.86
Shizhen Zhao,Xun Song,Xiuming Bu,Chong Zhu,Gang Wang,Fang Liao,Siwei Yang,Miao Wang
Because of the great demand for fluorescent materials, fluorescent dyes, semiconductor quantum dots, and carbon-based quantum dots have been studied extensively. However, the poor photostability and potential biological toxicity need to be resolved. In this study, we demonstrated the synthesis of a new biomass quantum dot, the polydopamine dot (PDADs), via a simple hydrothermal method under an acidic environment. This new biomass quantum dot showed not only remarkable photoluminescence properties (quantum yield = 0.93) but also a high stability and low toxicity. Moreover, these PDADs could be used as a fluorescent probe for the rapid detection of Cr(VI) (response time = 0.01 s). The detection limit (1 × 10 −11 M ) is the lowest detection limit reported for Cr(VI) fluorescent probes. The mechanism efficient quenching progress could have been due to the fast redox progress between the PDADs and Cr(VI). Moreover, we also showed a practical application of PDADs for Cr(VI) detection in vitro . © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44784.
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MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2024
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IF 4.2
Z.H.A.O.-X.U.A.N. Jiang
In this investigation, UiO-66-NH 2 was effectively synthesized through a solvothermal approach, utilizing benzoic acid and hydrochloric acid (HCl) as modulating agents. This synthesis process intentionally introduced defects mediated by benzoic acid, and the degree of these defects was precisely adjusted by the concentration of HCl. Subsequently, the material underwent a covalent modification process through an amidation reaction, resulting in the attachment of tetrakis (4-carboxyphenyl) porphyrin (TCPP). The results demonstrated a significant improvement in the photocatalytic reduction of Cr(VI), showcasing a 125 % elevation in reduction efficiency as compared to the unmodified UiO-66-NH 2 material serving as the baseline. The performance enhancement is due to the synergistic effect of the defect structure and TCPP modification, which enhances the light absorption, promotes charge transfer and separation, reduces the recombination rate, and improves the adsorption capacity and light absorption efficiency of Cr(VI). This research introduces an innovative approach and a highly effective catalyst, offering a novel solution for modifying metal-organic frameworks (MOFs) and enhancing their photocatalytic performance in the reduction of Cr(VI).
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高影响因子
Surfaces and Interfaces
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2024
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IF 5.7
Jiaqi Ma,Linkun Fan,Xusheng Wang,Lan Li,Yiming Zhang,Guixia Zhao,Bo Chai,Junkuo Gao
Cr(VI) stands as a profoundly toxic chemical and photocatalysis technology has shown promising potential in photocatalytic reduction of Cr(VI) to Cr(III), where the reduced Cr(III) is less toxic and can be further precipitated in a wide pH range. Metal-organic frameworks (MOFs), as emerging class of porous coordination polymers, is expected to be ideal platform for photocatalysis. In this study, defect engineering on MOFs was applied to promote photoreduction of Cr(VI). The obtained oxygen vacancy-containing MIL-125-NH 2 samples showed modified electron structure, adjusted surface and porous properties, and enriched active sites. Among these oxygen vacancy-containing MIL-125-NH 2 samples, the 300-M (MIL-125-NH 2 heated at 300 °C for 2 h under N 2 atmosphere) displayed the most remarkable performance in terms of photocatalytic Cr(VI) reduction. The pronounced efficacy of 300-M is evident from the achieved removal rate of Cr (VI), reaching an impressive 98 % in just 20 mins (19.6 mg Cr(VI) g −1 cata min −1 ), in stark contrast to MIL-125-NH 2 , which exhibited a modest removal rate of 53 %. Remarkably, the k-value for 300-M is 5.1 times that of MIL-125-NH 2 , further underscoring the superior efficiency of 300-M. The photoreduction mechanism of 300-M was further substantiated through a battery of advanced characterization techniques including transient photocurrent, electrochemical impedance spectroscopy, fluorescence spectroscopy, the Mott-Schottky analysis, and electron spin resonance. Those results disclosed that oxygen vacancies and mesopores introduced via controlled heat treatment play a pivotal role in facilitating the photoreduction of Cr(VI) within the MIL-125-NH 2 structure. More advanced characterizations for the structures of photocatalysts and the photocatalytic mechanisms including charge transfer path need further studied. The systematic exploration of temperature-dependent effects on material properties opens avenues for future research in designing efficient and versatile MOF-based photocatalysts for environmental remediation applications.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
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IF 9
Yunqi Zhou,Ye Yuan,Xinlei Liu,Zhi Wang
Metal-organic framework (MOF) membranes with proper pore size distribution and functional groups are generally more suitable for separation. Most MOFs are characterized by a hierarchical pore structure, which possesses large cavities surrounded by small windows. Fabrication of MOF membranes only retaining microporous fragment structure is a workable method to narrow pore size distribution. In this study, well-grown NH 2 -MIL-101(Cr) fragment membranes were fabricated for CO 2 separation by adjusting acetic acid – ligand – metal ratio to balance the nucleation and growth. NH 2 -MIL-101(Cr) fragment has a similar chemical structure to NH 2 -MIL-101(Cr) as expected, but only small pores with size around 0.56 nm is retained. The NH 2 -MIL-101(Cr) fragment membranes exhibited CO 2 /N 2 selectivity of about 37 with CO 2 permeance up to 6104 GPU.
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