JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2020
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IF 3.306
Yongsheng Yang,Zhiduo Liu,Da Chen,Bingli Gu,Bo Gao,Zihao Wang,Qinglei Guo,Gang Wang
In this work, nitrogen-doped graphene quantum dots (N-GQDs) with high blue fluorescence are synthesized by the one-pot hydrothermal method from benzimidazoles. The as-fabricated N-GQDs possess a homogeneous size of 3.8 nm, good crystallinity, pip photostability, good water soluble, and a high quantum yield of about 25 %. In addition, it is found that the fluorescence of N-GQDs can be obviously quenched by tetracycline (TC) and elevated temperature. The detection of TC is implemented, with a detection limit of 0.21 μmol L −1 . For the temperature sensing, the fluorescence intensity shows a linear reduction between 25 °C and 100 °C. Moreover, reversible and stable abilities of temperature sensing are demonstrated. Owing to the superior optoelectronic properties, white light emitting diodes (WLEDs) using the N-GQDs as the phosphor are fabricated, and the CIE coordinates is (0.357, 0.315) with the color temperature of 4427 K. The results reported here will expand the multiple applications of N-GQDs in environment monitoring, biosensing engineering and optoelectronic devices.
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高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Y. Su,C. Li,C. Yao,L. Xu,J. Xue,W. Yuan,J. Liu,M. Cheng,S. Hou
The Palladium (Pd) nanoparticles were immobilized on the boron (B), nitrogen (N) doped porous carbon (BNC-50) through replacing cobalt path at room temperature, which was derived from the high-temperature pyrolysis of the modified Zeolitic Imidazolate Frameworks (ZIF) composes coated with 5-boronoisophthalic acid. The Pd nanoparticles could be uniformly dispersed on the BNC-50 supports by replacement reaction to effectively avoid the Pd nanoparticles agglomeration. Meanwhile, the B, N doping can further grapple the palladium nanoparticles with luxuriant activity sites during the loading process. The highly order carbon frameworks also offer more porous paths and interspace to enhance the mass and charge delivery. Therefore, the synthetic catalysis of palladium nanoparticles immobilized on the porous B, N-doped carbon displays excellent activity (Pd/BNC-50) for ethanol oxidation reaction (EOR). The catalytic activities of the Pd/BNC-50 with peak current density (2638.41 mA mg −1 ) are 3.77 times than that of Pd/C in the basic reaction solution.
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CRYSTENGCOMM
·
2020
·Vol. 23
·期 4
·884-891
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IF 3.117
Changle Wang,Lipeng Zhang,Ping Yang
Transition-metal phosphides have been identified as effective materials for improving electrocatalytic hydrogen evolution. In this study, Ni2P, Co2P, and NiCoP yolk–shell structures were embedded in N- and P-doped carbon nanofibers (NPNFs) by controlling the heat-treatment procedure of the fiber precursors. The hydrogen evolution reaction (HER) activity of the samples was tested. The formation process of phosphides introduced a large number of surface defects that act as active sites to improve H2 evolution. NPNF embedding composite NiCoP particles exhibited better performance compared with Ni2P–NPNFs and Co2P–NPNF samples in acidic conditions. In the case of a molar ratio Ni : Co : P of 1 : 1 : 1, NiCoP-decorated NPNFs revealed the best HER performance, which is ascribed to the loading of NiCoP composite particles, which greatly increased the specific surface area. NiCoP–NPNFs exhibited overpotentials of 183 and 280 mV at current densities of 1 mA cm−2 and 10 mA cm−2, respectively, with a Tafel slope of 94.5 mV dec−1.
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高影响因子
ENVIRONMENTAL POLLUTION
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2020
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IF 6.793
Wanfeng Wang,Panqing Yang,Yanling Guo,Haoran Ji,Fang Liang
Four phenylurea herbicides (PUHs) were assessed for degradation and transformation into N-nitrosodimethylamine (NDMA) under three oxidation conditions (chlorine (Cl 2 ), chlorine dioxide (ClO 2 ), and ozone (O 3 )) from an aqueous solution. Removal ratios correlated with the numbers of halogen elements contained in PUHs (isoproturon (0) > chlorotoluron (1 Cl) > diuron (2 Cl) > fluometuron (3 F) ), and the degradation efficiencies of oxidants from fastest to slowest were: O 3 , ClO 2 , and Cl 2 . NDMA can be generated directly from the ozonation of PUHs. Further, compared with chloramination alone, ozonation prominently promoted NDMA formation potential (NDMA-FP) during post-chloramination, and NDMA-FPs increased approximately 23–68 times than those during ozonation only at 2.5 mg/L O 3 over 10 min; molar yields of NDMA from highest to lowest were 11.1% (isoproturon), 1.17% (chlorotoluron), 1.0% (diuron), and 0.73% (fluometuron). The PUH degradation kinetics data during ozonation agreed with the pseudo-first-order model. The rate constant k obs were 0.31 × 10 −3 –19.8 × 10 −3 s −1 . The k obs and removal ratios of PUHs during ozonation partially scaled with the mass, LogK ow , and Henry’s constants of PUHs. Comparisons of measured NDMA-FPs with calculated NDMA-FPs from residual PUH after oxidation showed that the intermediates produced during ozonation facilitated NDMA-FPs; this contribution was also observed for chlorotoluron and isoproturon during ClO 2 oxidation. Examination of reaction mechanisms revealed that tertiary amine ozonation, N-dealkylation, hydroxylation, the cleavage of N–C bonds, ammonification , and nitrification occurred during the ozonation of PUHs, and the dimethylamine (DMA) functional groups could be decomposed directly and transformed into NDMA via the formation of the intermediate unsymmetrical dimethylhydrazine . NDMA is also formed from the reaction between DMA and phenylamino-compounds. Clarifying primary degradation products of PUHs and transformation pathways of NDMA during oxidation processes is useful to optimize treatment processes for water supplies.
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 13
·7862-7878
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IF 4.22
Cao Xue-Fang,Yue Pan,Wei Qiu-Rui,Dang Yun-Fei,Zhang Si-Qi,Wei Zhi-Xian,Wang Rong-Zhen
In this study, a solar-driven photocatalyst La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) with p – n heterojunction structure was synthesized and characterized. The magnetic, photocatalytic properties, Fenton-like action and the synergistic effect of the photocatalysis and Fenton-like on methyl orange (MO) degradation of La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) were also investigated. Results show that p – n heterojunction was formed, and it has considerable photocatalytic properties under ultraviolet light and solar irradiation. More importantly, La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) also exhibits Fenton-like catalytic performance in the presence of H 2 O 2 and oxalic acid (OA). The main reactive radicals of the La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 –H 2 O 2 –OA–sunlight system are h + , · OH and · O 2 − . The chemical oxygen demand removal rate of MO wastewater in La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%)–H 2 O 2 –oxalic acid–sunlight system reached 72.4%; the value was higher than that of the sum of single photocatalysis (34.5%) and Fenton-like-dark system (27.6%), indicating that there is a synergistic effect between the photocatalysis and Fenton-like on MO degradation. In addition, La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) displays approximately superparamagnetism and has higher saturated magnetization ( M s ), low coercive force and residual magnetism. So it can be easily recovered by an external magnetic field and can be reused 6 times. It was anticipated that La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) with p – n heterojunction structure is a stable and reusable solar-light-driven magnetic photocatalyst and has great potential applications for wastewater treatment. Graphical abstract The magnetic La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) with p – n heterojunction structure was synthesized and characterized by different methods. The magnetic, photocatalytic properties, Fenton-like action and the synergistic effect of the photocatalysis and Fenton-like on methyl orange (MO) degradation of La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%) were also investigated. It is not only a solar-driven photocatalyst with high efficiency, but also shows excellent Fenton-like catalytic effect. And the photocatalysis and Fenton-like system exhibited synergetic catalytic effect on MO degradation by La 0.7 Sr 0.3 MnO 3 /α-Fe 2 O 3 (20%). Furthermore, near superparamagnetic characteristics of the catalyst make it easy to recycle by the external magnetic field and can be reused for 6 times, suggesting that it is a stable multifunctional catalyst.
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CARBON
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2021
·
IF 9.594
Mengmeng Yang,Qingquan Kong,Wei Feng,Weitang Yao
In this study, N/O co-doped cage-type biomass carbon (NOBC) was prepared through a simple and facile hydrothermal reaction and two-step carbonization method. As the anode of a potassium ion battery, NOBC displays a superhigh long-cycling performance and a super high rate performance. NOBC-2 provides an excellent reversible capacity of 251.2 mAh g −1 after 1500 cycles at 0.5 A g −1 , and an excellent performance of 334.6 mAh g −1 at a high current density of 5 A g −1 (after 2000 cycles). The reversible capacity of 124.19 mAh g −1 can be maintained even after 5000 cycles at 10 A g −1 . The excellent performance of NOBC is attributed to the unique hollow cage structure, internal 3D carbon network structure and N/O co-doping. Based on the results of detailed fundamental analysis, the pseudo-capacitance mechanism contributes to the higher K ion storage process in NOBC-2. Density functional theory (DFT) calculations further show that N/O double doping can promote the adsorption of K ions in biomass carbon materials and improve the conductivity of the materials. The simple synthesis route and excellent electrochemical performance provide new insights for the search for novel carbon-based K storage anode materials with high energy and long cycle life.
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ACS Applied Nano Materials
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2020
·
IF 0
Wei Zhao,Shuang Liu,Huishu Wang,Jun Yang,Xinhan Chen
Heterogeneous Pd has been developed as a well-known catalyst for debenzylation reactions via hydrogenative C–N bond cleavage. However, the extensive applications are still limited owing to a high loading and usage amount of the noble metal. Herein, well-dispersed Pd nanocatalysts over TiO2 were explored with a deposition–precipitation method and characterized by FESEM, physical adsorption, XRD, TEM, and XPS. It was proposed that the ultrasmall and electron-rich Pd nanoparticles can be enhanced over TiO2 rather than C, Al2O3, or SiO2. As representatives, the debenzylations of hexabenzylhexaazaisowurtzitane (HBIW) and tetraacetyldibenzylhexaazaisowurtzitane (TADBIW), which are key steps for the synthesis of CL-20 with the highest energy and density, were selected to evaluate the catalytic performances. It was found that Pd/TiO2 exhibited considerably low usage with high yields in the debenzylation processes of not only HBIW (1 wt ‰) but also TADBIW (4 wt ‰). Meanwhile, the superior catalytic activities can be maintained in the different reaction scales and can be repeated for TADBIW hydrodebenzylation. Hence, Pd nanoparticles supported on TiO2 can be considered to be suitable catalysts for highly efficient catalytic synthesis for hydrogenative C–N bond cleavage.
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Wenjie Xue,Hongxia Liu,Baohua Mao,Honglei Liu,Minghuang Qiu,Chengguang Yang,Xinqing Chen,Yuhan Sun
Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al 2 O 3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.
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ENERGY & FUELS
·
2020
·
IF 3.421
Dongxing Wang,Ying Wang,Xiaochen Wang,Funan Guo,Yuanqi Bai
As a promising alternative fuel with favorable properties and attractive prospects, the application of n-hexanol in diesel engines has aroused the interest of researchers. This study investigated the effects of mixing with n-hexanol on the morphology, nanostructure, graphitization, and oxidation reactivity of soot particles generated from a diesel engine. Experiments were performed on a turbocharged, four-cylinder direct-injection diesel engine fueled with D100 (neat diesel fuel), DH15 (15% n-hexanol and 85% diesel, v/v), and DH30 (30% n-hexanol and 70% diesel, v/v), respectively. Under the constant torque of 125 N·m, two typical speeds of 1370 and 2150 rpm were selected. Transmission electron microscopy (TEM), Raman spectroscopy (RS), and thermogravimetric analysis (TGA) were used to characterize particulate samples. TEM images showed that DH15 and DH30 particles had smaller primary particle diameters in comparison with neat diesel particles. Moreover, with the increase of the n-hexanol content in mixtures, the interlayer distance increased, indicating a more disordered nanostructure. RS results showed that soot samples generated from n-hexanol/diesel blended fuels had a lower degree of graphitization with larger ID1/IG and AD1/AG and more amorphous carbon with larger ID3/IG and AD3/AG. Based on TGA, it can be deduced that the DH30 soot sample obtained at the engine speed of 1370 rpm was easier to be oxidized in the DPF regeneration process for an 8.23% reduction in Tmax compared with D100 soot. Furthermore, activation energy of soots sampled at the engine speed of 2150 rpm decreased from 123.0 kJ/mol for D100 soot, to 109.6 kJ/mol for DH15 soot, and to 101.2 kJ/mol for DH30 soot, respectively. Regarding the effect of engine speeds on physicochemical characteristics of particles, results showed that the soot has higher oxidation activity under higher engine speed.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Xiao-Lu Sun,Zan Liu,Zhi-Lin Cheng
This report introduced the facile synthesis of the carbon-nanofiber films reinforced by halloysite nanotubes (HNTs) via electrospinning. The HNTs-reinforced N-doped carbon-nanofiber films (PAN/HNTs-CNFs) possessed the higher strength and toughness while keeping the prospective adsorption capability for different sulfur compounds in oil due to the higher N doping content. The PAN/HNTs-CNFs were produced by firstly electrospinning for the HNTs-filled polyacrylonitrile (PAN) nanofiber films, followed by the high-temperature carbonization for the conversion of the polymer films into the carbon-nanofiber films with the N doping. The characterizations testified that the HNTs were capable of fulfilling the uniform and disordered dispersion in the carbon-nanofibers. For overcoming the toughness of the carbon-nanofiber film, the HNTs filling the obviously improved the mechanical performance of the carbon-nanofiber films by the pulling-out and bridging effect. Due to accessing the lipophilic and acid surface, abundant hierarchical pore structure and highly N-doping content, the PAN/HNTs-CNFs exhibited the remarkable adsorption performances for thiophene, benzothiophene, and dibenzothiophene (46.73 mg S/g, 38.4 mg S/g and 35.03 mg S/g for 800 ppm sulfur model oil), especially being suitable to the adsorption of thiophene. Furthermore, the study on the adsorption kinetics, equilibrium isotherms, and thermodynamics of thiophene over the PAN/HNTs-CNFs were conducted to discuss the adsorption mechanism.
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Meng Chen,Wei Lu,Hejun Zhu,Leifeng Gong,Ziang Zhao,Yunjie Ding
Linear α-olefins (C8–C12 α-olefin, LAOs) are acknowledged as high-value-added chemicals in both lubricant production and the polyolefin industry. An alternative route to the synthesis of high-purity LAOs is the dehydration of linear long-chain n-alcohols, whereas elevating the activity and selectivity of catalysts remains a challenge. Herein, we presented that on using sodium-modified γ-Al2O3 as the catalyst, a high selectivity (up to 96.87%) to 1-decene was achieved, and an optimized experimental condition (329 °C and 0.25 h–1) was found using the response surface method. Characterization results including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), pyrolysis (Py)-IR, NH3-temperature-programmed desorption (TPD), and CO2-TPD showed that a suitable ratio (∼0.4 wt %) of sodium impregnation could inhibit the strong acid sites of the catalyst, and sodium impregnation led to the formation of additional base sites, which accounted for the synergistic effect with other acid sites to promote further conversion of ethers to olefins. This work is of significance for the synthesis of LAOs from long-chain n-alcohols.
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高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
·
IF 3.807
Xinyu Zheng,Yingcai Hu,Huizi Li,Bolun Han,Ruiyu Lin,Biao Huang
Metal-organic frameworks (MOFs) of type ZIF-67 via simple heat- treatment process was employed to prepare N-doped carbon nanotube frameworks (NCNTFs). Whereafter, an electroanalysis method using NCNTFs as the modify material was constructed for selective sensing of hydroquinone (HQ) and catechol (CC). Both HQ and CC can be independently determined in mixed solutions. The anodic peak currents of HQ increase linearly in two concentration ranges, one from 0.8 to 100 and another from 100 to 200 μM. Also, the anodic peak currents for CC increase linearly in the concentration ranges of 0.8–40 μM and 40–120 μM. The detection limits are 0.17 μM and 0.12 μM for HQ and CC, respectively. The sensor was used to detect these two isomers in spiked lake water, and recoveries for HQ and CC are 91.6–95.0% and 95.3–105.0%, respectively.
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危险品化学品经营许可证（带存储）